Search Results

Search found 4879 results on 196 pages for 'karthik ram'.

Page 104/196 | < Previous Page | 100 101 102 103 104 105 106 107 108 109 110 111  | Next Page >

  • WPF on a iX104 Tablet PC - efficient enough?

    - by Casimodo72
    Hi, I'm considering to use WPF for an application running on an iX104 (unfortunately I don't have one of those yet). Do you guys think that this combination would be efficient enough? Or is WPF just to slow for such a machine, so better stick with WinForms? Relevant specs of the iX104: Intel Pentium U2500 CoreDuo 2x 1.2 GHz 1 GB RAM, optional 2 GB 10.4" TFT, XGA 1024x768 Regards, Kasimier

    Read the article

  • how to build and run core apps of ics like settings, camera etc on windows

    - by user1495186
    I have downloaded ics 4.0.3 source code, want to modify native settings, what i have to do is 1) add custom modifications to the settings 2) recompile native settings with added modifications 3) build the source code 4) generate a customized build to work on all android devices. How can I achieve the above thing? Every suggestion is appreciated. Thanks in advance. FYI: Using win7,4gb ram, intel i5 processor. Installed cygwin,git.

    Read the article

  • How to increase memory allocation to program

    - by Vaibhav
    When I try to initialize a 3D array of size 300*300*4 in a C program, my program stops running and reports stack overflow error. The system I am using has 3GB RAM, which should be sufficeint. Is there any way to increase memory allocated to a program? I am using Dev C++ on Windows Vista.

    Read the article

  • MySQL select one field from table WHERE condition is in multiple rows

    - by Alex
    Tried to find the answer, but still couldn't.. The table is as follows: id, keyword, value 1 display 15.6 1 harddrive 320 1 ram 3 So what i need is something like this.. Select an id from this table where (keyword="display" and value="15.6") AND (keyword="harddrive" and value="320") There's also a possibility that there will be 3 or 4 such keyword conditions which should result into returning one id (one row) It seems there's something to deal with UNION but i didn't use it before so i can't figure it out Thanks in advance

    Read the article

  • Tomcat 6 is really UNSTABLE when redeploying web apps

    - by EugeneP
    Do you know how to make it more stable, maybe properties to set, memory to allocate? It always hangs up when redeploying web apps, thru manager (wars), web interface or maven plugin. every second time it gives PermGenSpace, no memory errors etc. on my local machine 3gb ram. It looks like it should be manually set up to work in a stable way. How to fix such a problem?

    Read the article

  • How much memory is my iphone app using (from Simulator)

    - by Jonathan
    I know this has something to do with Instruments, but well it's kind of confusing and searching for Instruments on Google doesn't help much. I'd like to know how well my app runs, like how much memory it uses. I just don't know where to find something like: "As close as we can tell from the simulator you'll app will currently be using xx MBs of RAM on a real iphone device." I need help on how to get this information.

    Read the article

  • How to copy a ram_base file to disk efficiently

    - by Hui Jin
    I want to copy a large a ram-based file (located at /dev/shm direcotry) to local disk, is there some way for an efficient copy instead of read char one by one or create another piece memory? I can use only C language here. Is there anyway that I can put the memory file directly to disk? Thanks!

    Read the article

  • Two imageViews vs one imageView and a canvas

    - by user3009842
    I have a bitmap and I want to scale it up to fill an ImageView and overlay the unscaled version of the bitmap on top. Which would be cheaper (in terms of memory and processor usage)? Using two ImageViews, one for each version of the bitmap Using a canvas and drawing on the singular bitmap, using one ImageView I saw this question about ImageView vs Canvas, but it doesn't address memory/processor concerns. My intuition says two ImageViews may use more RAM, while using a canvas would use more processing power while the drawing occurs.

    Read the article

  • Porting 32 bit C++ code to 64 bit - is it worth it? Why?

    - by NTDLS
    I am aware of some the obvious gains of the x64 architecture (higher addressable RAM addresses, ect)... but: What if my program has no real need to run in native 64 bit mode. Should I port it anyway? Are there any foreseeable deadlines for ending 32 bit support? Would my application run faster / better / more secure as native x64 code?

    Read the article

  • Processing large (over 1 Gig) files in PHP using stream_filter_*

    - by mike
    $fp_src=fopen('file','r'); $filter = stream_filter_prepend($fp_src, 'convert.iconv.ISO-8859-1/UTF-8'); while(fread($fp_src,4096)){ ++$count; if($count%1000==0) print ftell($fp_src)."\n"; } When I run this the script ends up consuming ~ 200 MB of RAM after going through just 35MB of the file. Running it without the stream_filter zips right through with a constant memory footprint of ~10 MB. What gives?

    Read the article

  • Returning the size of available virtual memory at run-time in C++

    - by Greenhouse Gases
    In C++ is there a predefined library function that will return the size of RAM currently available on a computer a program is being run on, at run-time? For instance, if an object is 4bytes, then can we divide the available virtual memory by 4 bytes to give an estimate of how many more objects could be stored by the program safely? I have used the sizeof() function to return the size of objects within my program. Thanks

    Read the article

  • Writing a script with the cmd prompt.

    - by Josh
    I'm trying to make a script that will place a list (in a .csv file) of processes that are running that take up more than 10 mb of RAM and shows the time + date the script was run. My teacher did this during his lecture but I can't remember how he did it. Just trying to figure out how to be better at IT. So my question is, can anyone help me with this? I don't even know where to start.

    Read the article

  • Is Appfogs pricing model sustainable?

    - by Kyle Finley
    I was looking at AppFog's Pricing and they appear to be giving 2GB of ram away for free, to nonpaying customers. This seems unprecedented for PAAS provodes--providers like Heroku and App Engine remove the app from memory if it has been inactive for certain amount of time. Does cloudfoundry work similarly? Am I wrong in assuming that in a few years appfog servers will be filled with inactive non paying applications?

    Read the article

  • mySQL: How many rows in a table before performance is affected?

    - by Industrial
    Hi everybody, Is there a "known limit" for columns & rows in a mySQL table that when passed, it can be safe to say that performance is severely affected? I've think that I had heard that there is a "golden number" that you really dont want to exceed in either columns or rows in a table. - Or is it all about the size of the index and available RAM + CPU on the server? Thanks!

    Read the article

  • Is an Object the smallest pageable unit in the Heap?

    - by DonnieKun
    Hi, If I have a 2 GB ram and I have an 2 instances of an Object which is 1.5 GB each, the operating system will help and context switch the pages to and from harddisk. What if I have 1 instances but is 3 GB. Can the same paging method breakdown this instances into 2 pages? Or will I encounter out-of-memory issue? Thanks.

    Read the article

  • Useful software for netbook?

    - by Moayad Mardini
    I'm looking for recommendations of good software that are particularly useful for netbooks. Software that run great on small screens and low CPU/RAM requirments. I'll start off with the following : Operating Systems: Ubuntu Netbook Remix. Easy Peasy: A fork of Ubuntu Netbook Remix that was once called UBuntu EEE. It isn't just for eeePCs though. Definitely worth a look if vanilla Netbook Remix isn't cutting it. (MarkM) Damn Small Linux (Source) Windows 7: With trimming the installation or compressing the Windows directory to fit on an 8GB SSD. (Will Eddins) nLite: A utility to install a lightweight version of Windows XP without the unnecessary components (like Media Player, Internet Explorer, Outlook Express, MSN Explorer, Messenger...). Utilites: TouchFreeze: To disable the touch pad while typing (Source) InSSIDer: Not only does it make it easier to find and keep a wireless connection, but it turns a netbook into the perfect mobile tool for troubleshooting wireless networks. (phenry) AltMove: Adds more functionality to your mouse for interacting with windows. (Rob) ASUS Font Resizer Utility and other tools by ASUS, specific to ASUS Eee PC series. Internet: Run FileZilla FTP client for a small screen : You can hide a lot of FileZilla's interface parts in the View menu, even the directory trees. Go into Settings = Interface and move the message log next to the transfer queue, if you haven't hidden them both or you want to see them. Select a theme with 16x16 icons. (Source) IDEs and Text Editors: Best lightweight IDE/Text Editor: A question on Stack Overflow that has many good suggestions of IDEs and general text editors for programmers. What’s a good linux C/C++ IDE for a low-res screen?: IDEs for Linux-powered netbooks. Online tools: Dropbox: Since the Netbook has limited disk space, you would like to use Cloud Apps like Dropbox and Ubuntu One so that you don't run out of space especially if you are on a holiday. Later when you go back to your desktop with big hard disk,you can take out the files from your dropbox repo. (Manish Sinha) Google products: like Docs, Calendar and Reader (aviraldg) Web sites and software lists: Netbookfiles.com: Netbook specific software downloads. Software Apps to Maximise your Netbook Battery Power: Netbooks are known for their portability. Not only are they small and lightweight but with their increased power efficiency, batteries can last much longer than conventional laptops. This also means you no longer have to carry a power adapter with you! Several brands emphasis the longevity of the battery as a strong selling point, and for those people who travel a lot, it sure is. Free Must-Have Netbook Apps: Finding software for netbooks can present challenges due to limited hard drive space, processor power, RAM, and screen real-estate. That doesn't mean you have to do without essential programs. The apps below cover all the bases -- entertainment, productivity, security, and communication -- without compromising on performance or usability. Best of all, they're free! Useful Netbook Software: With short battery lives and small resolution screens Netbooks, unlike many other computers on the market, could so with some specific software for their use. Now, not all of those I’ve found are specifically designed for Netbooks, but all are relevant. And they’re designed for Windows XP. The question is community wiki, so feel free to edit it. Updated, thank you all for suggestions.

    Read the article

  • Why do GPUs overheat?

    - by JAD
    About a year ago, I added a 9800GT (1 GB version) and a Corsair CX500 PSU to an HP M8000N computer. A few weeks ago, the HDD overheated and I decided to transfer the GPU & PSU to a new build, which consists of: i3 @ 3.3Ghz Gigabyte H61 Micro ATX Mobo 4GB RAM 500GB WD HDD DVD RW Drive Cooler Master Elite 430 Tower Once I had Win7 up and running, I installed all the essential drivers that came with the Gigabyte Mobo CD. However, whenever I tried installing the Graphics Media Accelerator driver, the computer would crash and enter an endless boot sequence on the next startup. I skipped installing this driver and installed the CD driver for the 9800GT, which by now is a year old. Everything was working fine, WEI rated my GPU at 6.6 graphics & aero performance. However, after updating my Nvidia drivers to the latest, the WEI dropped my rating to 3.3 for Aero, and 4.7 for graphics performance. Just to make sure that everything was ok, I ran Bad Company 2 on medium settings. The first few minutes ran just fine at a smooth framerate, so I dismissed this as Windows being Windows. About 6 hours later, I ran BC2 again. This time I averaged anywhere from 2-5 FPS. I checked the GPU temperature through GPU-Z, and it came back as 120C. The problem with this, is that the computer was on for six hours up to that point. Wouldn't the card have experienced a reactor core meltdown a lot sooner than that? Granted, the computer was "sleeping" some of the time, but still... The next day I took out a temperature gun and ran some tests. I would point the laser at a very specific area on the reverse side of the card (not the fan or "front"), and compare the temp reading with GPU-Z. After leaving the system on idle on idle for a few minutes, I ran BC2 twice. Here are the results: GPU-Z Reading / Temp Gun Reading / Time Null / 22.3°C / Comp is Off 53°C / 33.5°C / 1:49 78°C / 46°C / 1:53 - (First BC2 run; good framerate) 102°C / 64.6°C / 2:01 - (System is again on idle) 113°C / 64.8°C / 2:10 119°C / 71.8°C / 2:17 - (Second BC2 run; poor framerate) I should also mention that I also took a temp recording of another part of the GPU from 2:01-2:17. The temp in this area jumped from 75°C to 82.9°C in that time frame. This pretty much confirms that GPU-Z is reporting the temperature accurately, and the card is overheating. But I'd like to know why; the cars is doing nothing and still the temperature climbs at a steady rate. I thoroughly cleaned the GPU and PSU when I salvaged them from the old HP M8000N computer with a can of compressed air, dust cant be the issue. Similarly, the rest of the computer is brand new. I installed various Nvidia drivers, but no luck. It seems strange to me that a year-old card is suddenly failing on me; aren't they supposed to last at least two years? Could this be a driver issue? Is the motherboard faulty? Could the PSU be overfeeding the card on voltage? Neither case seems likely, as the CPU, RAM and otherwise the rest of the comp has worked flawlessly and has stayed well within respectable temp ranges (the i3 lingers around 50C, the HDD stays at 30C, so does the PSU). How can I pinpoint the issue?

    Read the article

  • Graphics card initialisation problems when booting - requires a "double" boot

    - by DMA57361
    Problem Outline When booting from cold (and my machine is disconnected from main power when off, but leaving it connected doesn't help) the graphics card (single PCI-e card GeForce 460) will not initialise on the first boot, leaving me with the motherboards on-board graphics (which kick in automatically if no PCI-e card is found). However, if I restart the computer - normally I do this by powering it off just after the numlock lights up on the keyboard (ie, just after POST/BIOS and before Windows takes over), wait for the system to whirr down, and power up again - the graphics card will work correctly. Once double-booted in this matter the system seems to work correctly - with no noticeable problems. This is reproducible every time I try to boot - it has been working like this for about a month now. Background Information Sept 2010 - I suffered a hardware malfunction (crashes in Windows and graphics corruption on BIOS screens). By way of spare hardware I determined that replacing the PSU removed the issue, so I replaced the PSU with a brand new one of slightly higher power (460W replaced with 500W). Oct 2010 - The problem resurfaced. I purchased a new graphics card (GeForce 460), which removed the problem. The new graphics card immediately started having the boot initialisation problems mentioned. I presumed there was a motherboard fault all along, but because the system worked once booted, and I was temporarily out of spare money, I left the system alone and continued to use it. Early/Mid Dec 2010 - In the space of 5 days I recieved 3 instances of hard drive corruption (seemlingly fixed by chkdsk and sfc in each case...). Since I was already under the impression the motherboard was faulty, I purchased a new one ASAP, this also required new RAM (as I dropped from 4 slots to 2 and didn't want to drop mem quantity). Past 3-4 weeks - With a brand new PSU, Graphics Card, Motherboard and RAM I'm suffering the problem outlined above. So, what could be causing this and how do I can resolve it? Additional Notes Once double-booted the system seems to work entirely correctly. The graphics card problem has occured on two entirely different motherboards. I do not have the opportunity to test the graphics card in a different computer (I've only the old motherboard, which is dubious, or a really old desktop that still has an AGP port). Under load (ie, modern games for long enough for temperatures to plateau) the system remains stable and performs as expected. The software that came with the new motherboard and SpeenFan both report all voltages and temperatures are within nominal bounds, when idle and when under load. I've looking over the BIOS settings for my motherboard multiple times and can find nothing that helps. This system is configured to run with everything at standard levels - no overclocking. I've tried booting the system with only the mobo and graphics card connected (thinking maybe my new PSU was too weak for the new gfx card, even though it meets the quoted PSU requirements for the card) but the same problem persists (and really if the PSU was weak I'd have problems with the system under load). When the gfx card does not initialise the fan on its cooling unit is running, possibly slower than otherwise - but this measurement is by eye and so unreliable.

    Read the article

  • Diagnosing Solaris 8 server memory and swap space usage

    - by datSilencer
    Hello everyone. Essentially, my question is related to memory allocation for Solaris virtual machines. I am running a couple of old Sun ONE 6 Java web servers on two Solaris 8 virtual machines. I see that there's a reasonable amount of swap space being used, but I'm not exactly sure if this could indicate a need to add more RAM to these machines. At service peak hours (mornings usually), the response time of the web application these servers host jumps up to at most 11 seconds (somewhat detrimental for a relatively simple web page loading action). Average response time at non peak times is about 5 seconds. What would you be able to infer about the RAM usage for these machines from the ouput below? Is this information reasonably sufficient? Or would I need to run some other commands to rule out server memory starvation? Finally, since there is a Java application at the core of the setup, I've also thought about: 1) Trace the heap's Object allocation to detect potential memory leaks. 2) Do some performance profiling to see if this instead related to networking delays. I mention this since the application talks with a single Oracle Database, but I would doubt this to be the case since they're pretty close from a network segmentation perspective. I appreciate any kind of insight and feedback you could provide. Thanks for your time and help. Server 1: 40 processes: 38 sleeping, 1 zombie, 1 on cpu CPU states: 99.1% idle, 0.4% user, 0.4% kernel, 0.0% iowait, 0.0% swap Memory: 2048M real, 295M free, 865M swap in use, 3788M swap free PID USERNAME THR PRI NICE SIZE RES STATE TIME CPU COMMAND 12676 webservd 112 29 10 616M 242M sleep 103:37 0.48% webservd 18317 root 1 59 0 23M 19M sleep 67:24 0.08% perl 9479 support 1 59 0 6696K 2448K cpu/1 0:11 0.05% top 8012 root 10 59 0 34M 704K sleep 80:54 0.04% java 1881 root 33 29 10 110M 13M sleep 33:03 0.02% webservd 7808 root 1 59 0 83M 67M sleep 7:59 0.00% perl 1461 root 20 59 0 5328K 1392K sleep 6:49 0.00% syslogd 1691 root 2 59 0 27M 680K sleep 4:22 0.00% webservd 24386 root 1 59 0 15M 11M sleep 2:50 0.00% perl 23259 root 1 59 0 11M 4240K sleep 2:42 0.00% perl 24718 root 1 59 0 11M 5464K sleep 2:29 0.00% perl 22810 root 1 59 0 19M 11M sleep 2:21 0.00% perl 24451 root 1 53 2 11M 3800K sleep 2:18 0.00% perl 18501 root 1 56 1 11M 3960K sleep 2:18 0.00% perl 14450 root 1 56 1 15M 6920K sleep 1:49 0.00% perl Server 2 42 processes: 40 sleeping, 1 zombie, 1 on cpu CPU states: 98.8% idle, 0.4% user, 0.8% kernel, 0.0% iowait, 0.0% swap Memory: 1024M real, 31M free, 554M swap in use, 3696M swap free PID USERNAME THR PRI NICE SIZE RES STATE TIME CPU COMMAND 5607 webservd 74 29 10 284M 173M sleep 20:14 0.21% webservd 15919 support 1 59 0 4056K 2520K cpu/1 0:08 0.09% top 13138 root 10 59 0 34M 1952K sleep 210:51 0.08% java 13753 root 1 59 0 22M 12M sleep 170:15 0.07% perl 22979 root 33 29 10 112M 7864K sleep 85:07 0.04% webservd 22930 root 1 59 0 3424K 1552K sleep 17:47 0.01% xntpd 22978 root 2 59 0 27M 2296K sleep 10:49 0.00% webservd 13571 root 1 59 0 9400K 5112K sleep 5:52 0.00% perl 5606 root 2 29 10 29M 9056K sleep 0:36 0.00% webservd 15910 support 1 59 0 9128K 2616K sleep 0:00 0.00% sshd 13106 root 1 59 0 82M 3520K sleep 7:47 0.00% perl 13547 root 1 59 0 12M 5528K sleep 6:38 0.00% perl 13518 root 1 59 0 9336K 3792K sleep 6:24 0.00% perl 13399 root 1 56 1 8072K 3616K sleep 5:18 0.00% perl 13557 root 1 53 2 8248K 3624K sleep 5:12 0.00% perl

    Read the article

  • GNU/Linux swapping blocks system

    - by Ole Tange
    I have used GNU/Linux on systems from 4 MB RAM to 512 GB RAM. When they start swapping, most of the time you can still log in and kill off the offending process - you just have to be 100-1000 times more patient. On my new 32 GB system that has changed: It blocks when it starts swapping. Sometimes with full disk activity but other times with no disk activity. To examine what might be the issue I have written this program. The idea is: 1 grab 3% of the memory free right now 2 if that caused swap to increase: stop 3 keep the chunk used for 30 seconds by forking off 4 goto 1 - #!/usr/bin/perl sub freekb { my $free = `free|grep buffers/cache`; my @a=split / +/,$free; return $a[3]; } sub swapkb { my $swap = `free|grep Swap:`; my @a=split / +/,$swap; return $a[2]; } my $swap = swapkb(); my $lastswap = $swap; my $free; while($lastswap >= $swap) { print "$swap $free"; $lastswap = $swap; $swap = swapkb(); $free = freekb(); my $used_mem = "x"x(1024 * $free * 0.03); if(not fork()) { sleep 30; exit(); } } print "Swap increased $swap $lastswap\n"; Running the program forever ought to keep the system at the limit of swapping, but only grabbing a minimal amount of swap and do that very slowly (i.e. a few MB at a time at most). If I run: forever free | stdbuf -o0 timestamp > freelog I ought to see swap slowly rising every second. (forever and timestamp from https://github.com/ole-tange/tangetools). But that is not the behaviour I see: I see swap increasing in jumps and that the system is completely blocked during these jumps. Here the system is blocked for 30 seconds with the swap usage increases with 1 GB: secs 169.527 Swap: 18440184 154184 18286000 170.531 Swap: 18440184 154184 18286000 200.630 Swap: 18440184 1134240 17305944 210.259 Swap: 18440184 1076228 17363956 Blocked: 21 secs. Swap increase 2400 MB: 307.773 Swap: 18440184 581324 17858860 308.799 Swap: 18440184 597676 17842508 330.103 Swap: 18440184 2503020 15937164 331.106 Swap: 18440184 2502936 15937248 Blocked: 20 secs. Swap increase 2200 MB: 751.283 Swap: 18440184 885288 17554896 752.286 Swap: 18440184 911676 17528508 772.331 Swap: 18440184 3193532 15246652 773.333 Swap: 18440184 1404540 17035644 Blocked: 37 secs. Swap increase 2400 MB: 904.068 Swap: 18440184 613108 17827076 905.072 Swap: 18440184 610368 17829816 942.424 Swap: 18440184 3014668 15425516 942.610 Swap: 18440184 2073580 16366604 This is bad enough, but what is even worse is that the system sometimes stops responding at all - even if I wait for hours. I have the feeling it is related to the swapping issue, but I cannot tell for sure. My first idea was to tweak /proc/sys/vm/swappiness from 60 to 0 or 100, just to see if that had any effect at all. 0 did not have an effect, but 100 did cause the problem to arise less often. How can I prevent the system from blocking for such a long time? Why does it decide to swapout 1-3 GB when less than 10 MB would suffice?

    Read the article

  • AMD 24 core server memory bandwidth

    - by ntherning
    I need some help to determine whether the memory bandwidth I'm seeing under Linux on my server is normal or not. Here's the server spec: HP ProLiant DL165 G7 2x AMD Opteron 6164 HE 12-Core 40 GB RAM (10 x 4GB DDR1333) Debian 6.0 Using mbw on this server I get the following numbers: foo1:~# mbw -n 3 1024 Long uses 8 bytes. Allocating 2*134217728 elements = 2147483648 bytes of memory. Using 262144 bytes as blocks for memcpy block copy test. Getting down to business... Doing 3 runs per test. 0 Method: MEMCPY Elapsed: 0.58047 MiB: 1024.00000 Copy: 1764.082 MiB/s 1 Method: MEMCPY Elapsed: 0.58012 MiB: 1024.00000 Copy: 1765.152 MiB/s 2 Method: MEMCPY Elapsed: 0.58010 MiB: 1024.00000 Copy: 1765.201 MiB/s AVG Method: MEMCPY Elapsed: 0.58023 MiB: 1024.00000 Copy: 1764.811 MiB/s 0 Method: DUMB Elapsed: 0.36174 MiB: 1024.00000 Copy: 2830.778 MiB/s 1 Method: DUMB Elapsed: 0.35869 MiB: 1024.00000 Copy: 2854.817 MiB/s 2 Method: DUMB Elapsed: 0.35848 MiB: 1024.00000 Copy: 2856.481 MiB/s AVG Method: DUMB Elapsed: 0.35964 MiB: 1024.00000 Copy: 2847.310 MiB/s 0 Method: MCBLOCK Elapsed: 0.23546 MiB: 1024.00000 Copy: 4348.860 MiB/s 1 Method: MCBLOCK Elapsed: 0.23544 MiB: 1024.00000 Copy: 4349.230 MiB/s 2 Method: MCBLOCK Elapsed: 0.23544 MiB: 1024.00000 Copy: 4349.359 MiB/s AVG Method: MCBLOCK Elapsed: 0.23545 MiB: 1024.00000 Copy: 4349.149 MiB/s On one of my other servers (based on Intel Xeon E3-1270): foo2:~# mbw -n 3 1024 Long uses 8 bytes. Allocating 2*134217728 elements = 2147483648 bytes of memory. Using 262144 bytes as blocks for memcpy block copy test. Getting down to business... Doing 3 runs per test. 0 Method: MEMCPY Elapsed: 0.18960 MiB: 1024.00000 Copy: 5400.901 MiB/s 1 Method: MEMCPY Elapsed: 0.18922 MiB: 1024.00000 Copy: 5411.690 MiB/s 2 Method: MEMCPY Elapsed: 0.18944 MiB: 1024.00000 Copy: 5405.491 MiB/s AVG Method: MEMCPY Elapsed: 0.18942 MiB: 1024.00000 Copy: 5406.024 MiB/s 0 Method: DUMB Elapsed: 0.14838 MiB: 1024.00000 Copy: 6901.200 MiB/s 1 Method: DUMB Elapsed: 0.14818 MiB: 1024.00000 Copy: 6910.561 MiB/s 2 Method: DUMB Elapsed: 0.14820 MiB: 1024.00000 Copy: 6909.628 MiB/s AVG Method: DUMB Elapsed: 0.14825 MiB: 1024.00000 Copy: 6907.127 MiB/s 0 Method: MCBLOCK Elapsed: 0.04362 MiB: 1024.00000 Copy: 23477.623 MiB/s 1 Method: MCBLOCK Elapsed: 0.04262 MiB: 1024.00000 Copy: 24025.151 MiB/s 2 Method: MCBLOCK Elapsed: 0.04258 MiB: 1024.00000 Copy: 24048.849 MiB/s AVG Method: MCBLOCK Elapsed: 0.04294 MiB: 1024.00000 Copy: 23847.599 MiB/s For reference here's what I get on my Intel based laptop: laptop:~$ mbw -n 3 1024 Long uses 8 bytes. Allocating 2*134217728 elements = 2147483648 bytes of memory. Using 262144 bytes as blocks for memcpy block copy test. Getting down to business... Doing 3 runs per test. 0 Method: MEMCPY Elapsed: 0.40566 MiB: 1024.00000 Copy: 2524.269 MiB/s 1 Method: MEMCPY Elapsed: 0.38458 MiB: 1024.00000 Copy: 2662.638 MiB/s 2 Method: MEMCPY Elapsed: 0.38876 MiB: 1024.00000 Copy: 2634.043 MiB/s AVG Method: MEMCPY Elapsed: 0.39300 MiB: 1024.00000 Copy: 2605.600 MiB/s 0 Method: DUMB Elapsed: 0.30707 MiB: 1024.00000 Copy: 3334.745 MiB/s 1 Method: DUMB Elapsed: 0.30425 MiB: 1024.00000 Copy: 3365.653 MiB/s 2 Method: DUMB Elapsed: 0.30342 MiB: 1024.00000 Copy: 3374.849 MiB/s AVG Method: DUMB Elapsed: 0.30491 MiB: 1024.00000 Copy: 3358.328 MiB/s 0 Method: MCBLOCK Elapsed: 0.07875 MiB: 1024.00000 Copy: 13003.670 MiB/s 1 Method: MCBLOCK Elapsed: 0.08374 MiB: 1024.00000 Copy: 12228.034 MiB/s 2 Method: MCBLOCK Elapsed: 0.07635 MiB: 1024.00000 Copy: 13411.216 MiB/s AVG Method: MCBLOCK Elapsed: 0.07961 MiB: 1024.00000 Copy: 12862.006 MiB/s So according to mbw my laptop is 3 times faster than the server!!! Please help me explain this. I've also tried to mount a ram disk and use dd to benchmark it and I get similar differences so I don't think mbw is to blame. I've checked the BIOS settings and the memory seem to be running at full speed. According to the hosting company the modules are all OK. Could this have something to do with NUMA? It seems like Node Interleaving is disabled on this server. Will enabling it (thus turning off NUMA) make a difference? foo1:~# numactl --hardware available: 4 nodes (0-3) node 0 cpus: 0 1 2 3 4 5 node 0 size: 8190 MB node 0 free: 7898 MB node 1 cpus: 6 7 8 9 10 11 node 1 size: 12288 MB node 1 free: 12073 MB node 2 cpus: 18 19 20 21 22 23 node 2 size: 12288 MB node 2 free: 12034 MB node 3 cpus: 12 13 14 15 16 17 node 3 size: 8192 MB node 3 free: 8032 MB node distances: node 0 1 2 3 0: 10 20 20 20 1: 20 10 20 20 2: 20 20 10 20 3: 20 20 20 10

    Read the article

  • Linux not buffering block I/O when the device is not "in use" (i.e. mounted)

    - by Radek Hladík
    I am installing new server and I've found an interesting issue. The server is running Fedora 19 (3.11.7-200.fc19.x86_64 kernel) and is supposed to host a few KVM/Qemu virtual servers (mail server, file server, etc..). The HW is Intel(R) Xeon(R) CPU 5160 @ 3.00GHz with 16GB RAM. One of the most important features will be Samba server and we have decided to make it as virtual machine with almost direct access to the disks. So the real HDD is cached on SSD (via bcache) then raided with md and the final device is exported into the virtual machine via virtio. The virtual machine is again Fedora 19 with the same kernel. One important topic to find out is whether the virtualization layer will not introduce high overload into disk I/Os. So far I've been able to get up to 180MB/s in VM and up to 220MB/s on real HW (on the SSD disk). I am still not sure why the overhead is so big but it is more than the network can handle so I do not care so much. The interesting thing is that I've found that the disk reads are not buffered in the VM unless I create and mount FS on the disk or I use the disks somehow. Simply put: Lets do dd to read disk for the first time (the /dev/vdd is an old Raptor disk 70MB/s is its real speed): [root@localhost ~]# dd if=/dev/vdd of=/dev/null bs=256k count=10000 ; cat /proc/meminfo | grep Buffers 2621440000 bytes (2.6 GB) copied, 36.8038 s, 71.2 MB/s Buffers: 14444 kB Rereading the data shows that they are cached somewhere but not in buffers of the VM. Also the speed increased to "only" 500MB/s. The VM has 4GB of RAM (more that the test file) [root@localhost ~]# dd if=/dev/vdd of=/dev/null bs=256k count=10000 ; cat /proc/meminfo | grep Buffers 2621440000 bytes (2.6 GB) copied, 5.16016 s, 508 MB/s Buffers: 14444 kB [root@localhost ~]# dd if=/dev/vdd of=/dev/null bs=256k count=10000 ; cat /proc/meminfo | grep Buffers 2621440000 bytes (2.6 GB) copied, 5.05727 s, 518 MB/s Buffers: 14444 kB Now lets mount the FS on /dev/vdd and try the dd again: [root@localhost ~]# mount /dev/vdd /mnt/tmp [root@localhost ~]# dd if=/dev/vdd of=/dev/null bs=256k count=10000 ; cat /proc/meminfo | grep Buffers 2621440000 bytes (2.6 GB) copied, 4.68578 s, 559 MB/s Buffers: 2574592 kB [root@localhost ~]# dd if=/dev/vdd of=/dev/null bs=256k count=10000 ; cat /proc/meminfo | grep Buffers 2621440000 bytes (2.6 GB) copied, 1.50504 s, 1.7 GB/s Buffers: 2574592 kB While the first read was the same, all 2.6GB got buffered and the next read was at 1.7GB/s. And when I unmount the device: [root@localhost ~]# umount /mnt/tmp [root@localhost ~]# cat /proc/meminfo | grep Buffers Buffers: 14452 kB [root@localhost ~]# dd if=/dev/vdd of=/dev/null bs=256k count=10000 ; cat /proc/meminfo | grep Buffers 2621440000 bytes (2.6 GB) copied, 5.10499 s, 514 MB/s Buffers: 14468 kB The bcache was disabled while testing and the results are same on faster (newer) HDDs and on SSD (except for the initial read speed of course). To sum it up. When I read from the device via dd first time, it gets read from the disk. Next time I reread it gets cached in the host but not in the guest (thats actually the same issue, more on that later). When I mount the filesystem but try to read the device directly it gets cached in VM (via buffers). As soon as I stop "using" it, buffers are discarded and the device is not cached anymore in the VM. When I looked into buffers value on the host I realized that the situation is the same. The block I/O gets buffered only when the disk is in use, in this case it means "exported to a VM". On host, after all the measurement done: 3165552 buffers On the host, after the VM shutdown: 119176 buffers I know it is not important as the disks will be mounted all the time but I am curious and I would like to know why it is working like this.

    Read the article

  • Is Apache 2.2.22 able to sustain 1.000 simultaneous connected clients?

    - by Fnux
    For an article in a news paper, I'm benchmarking 5 different web servers (Apache2, Cherokee, Lighttpd, Monkey and Nginx). The tests made consist of measuring the execution times as well as different parameters such as the number of request served per second, the amount of RAM, the CPU used, during a growing load of simultaneous clients (from 1 to 1.000 with a step of 10) each client sending 1.000.000 requets of a small fixed file, then of a medium fixed file, then a small dynamic content (hello.php) and finally a complex dynamic content (the computation of the reimbursment of a loan). All the web servers are able to sustain such a load (up to 1.000 clients) but Apache2 which always stops to respond when the test reach 450 to 500 simultaneous clients. My configuration is : CPU: AMD FX 8150 8 cores @ 4.2 GHz RAM: 32 Gb. SSD: 2 x Crucial 240 Gb SATA6 OS: Ubuntu 12.04.3 64 bit WS: Apache 2.2.22 My Apache2 configuration is as follows: /etc/apache2/apache2.conf LockFile ${APACHE_LOCK_DIR}/accept.lock PidFile ${APACHE_PID_FILE} Timeout 30 KeepAlive On MaxKeepAliveRequests 1000000 KeepAliveTimeout 2 ServerName "fnux.net" <IfModule mpm_prefork_module> StartServers 16 MinSpareServers 16 MaxSpareServers 16 ServerLimit 2048 MaxClients 1024 MaxRequestsPerChild 0 </IfModule> User ${APACHE_RUN_USER} Group ${APACHE_RUN_GROUP} AccessFileName .htaccess <Files ~ "^\.ht"> Order allow,deny Deny from all Satisfy all </Files> DefaultType None HostnameLookups Off ErrorLog ${APACHE_LOG_DIR}/error.log LogLevel emerg Include mods-enabled/*.load Include mods-enabled/*.conf Include httpd.conf Include ports.conf LogFormat "%v:%p %h %l %u %t \"%r\" %>s %O \"%{Referer}i\" \"%{User-Agent}i\"" vhost_combined LogFormat "%h %l %u %t \"%r\" %>s %O \"%{Referer}i\" \"%{User-Agent}i\"" combined LogFormat "%h %l %u %t \"%r\" %>s %O" common LogFormat "%{Referer}i -> %U" referer LogFormat "%{User-agent}i" agent Include conf.d/ Include sites-enabled/ /etc/apache2/ports.conf NameVirtualHost *:8180 Listen 8180 <IfModule mod_ssl.c> Listen 443 </IfModule> <IfModule mod_gnutls.c> Listen 443 </IfModule> /etc/apache2/mods-available <IfModule mod_fastcgi.c> AddHandler php5-fcgi .php Action php5-fcgi /cgi-bin/php5.external <Location "/cgi-bin/php5.external"> Order Deny,Allow Deny from All Allow from env=REDIRECT_STATUS </Location> </IfModule> /etc/apache2/sites-available/default <VirtualHost *:8180> ServerAdmin webmaster@localhost DocumentRoot /var/www/apache2 <Directory /> Options FollowSymLinks AllowOverride None </Directory> <Directory /var/www/> Options Indexes FollowSymLinks MultiViews AllowOverride None Order allow,deny allow from all </Directory> ScriptAlias /cgi-bin/ /usr/lib/cgi-bin/ <Directory "/usr/lib/cgi-bin"> AllowOverride None Options +ExecCGI -MultiViews +SymLinksIfOwnerMatch Order allow,deny Allow from all </Directory> ErrorLog ${APACHE_LOG_DIR}/error.log LogLevel emerg ##### CustomLog ${APACHE_LOG_DIR}/access.log combined Alias /doc/ "/usr/share/doc/" <Directory "/usr/share/doc/"> Options Indexes MultiViews FollowSymLinks AllowOverride None Order deny,allow Deny from all Allow from 127.0.0.0/255.0.0.0 ::1/128 </Directory> <IfModule mod_fastcgi.c> AddHandler php5-fcgi .php Action php5-fcgi /php5-fcgi Alias /php5-fcgi /usr/lib/cgi-bin/php5-fcgi FastCgiExternalServer /usr/lib/cgi-bin/php5-fcgi -host 127.0.0.1:9000 -pass-header Authorization </IfModule> </VirtualHost> /etc/security/limits.conf * soft nofile 1000000 * hard nofile 1000000 So, I would trully appreciate your advice to setup Apache2 to make it able to sustain 1.000 simultaneous clients, if this is even possible. TIA for your help. Cheers.

    Read the article

< Previous Page | 100 101 102 103 104 105 106 107 108 109 110 111  | Next Page >