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  • No dual cpu support for VirtualBox with a CPU that doesn't support multicore?

    - by djangofan
    With VMWare it works fine and I can run multiple cores on a VMWare image. With Sun VirtualBox I can only run 1 cpu on a image. Its annoying. Why does Sun Virtualbox not work the same as VMWare in this respect?? My CPU is: XEON 3.00GHz Intel 90nm 2MBCache QUAD CPU x14 Socket 604 mPGA Family 15 Model 4(04) Stepping 3 Revision 05 MMX SSE3 XD SIV.exe tells me: No virtual machine extensions x86 with 64-bit support NO IA64 support MPS but with NO MCP 2 physical processors, 2 cores, 4 logical processors

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  • Intel turbo boost - in reality

    - by gisek
    I have an Intel i7-3630QM processor in my laptop. Its speed is supposed to be from 2.4 to 3.4 GHz in turbo boost mode. In reality, will it ever run all cores on full speed (3.4GHz mentioned above) at the same time? I heard somewhere that this additional 1GHz is shared between all cores in laptops. If the boost is 1GHz per core it's pretty impressive (over 40% speed up). What does it really look like? How long can a processor run in turbo mode?

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  • upgrade from windows server 2008 r2 std to enterprise

    - by Ravi
    We recently had to upgrade our servers from Win 2008 R2 Standard to Enterprise. The upgrade method was DISM. After the upgrade, a lot of weird things started to happen. Though Windows says it's been properly activated, we lost 1) RDP settings (disappeared from the Remote Setting tab of Properties of My Computer) 2) The option to join a domain is grayed out 3) The server had to 2 physical processors 12 cores each. Now, task manager or windows sees only 1 processor (or only 12 cores) 4) the amount of physical ram on this sever is 32 GB (Windows reports only 4 GB are usable) Has anyone encountered this before ? Thanks Ravi

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  • Should I split my website into different servers

    - by Nyxynyx
    I have a website where a user uploads photos, the photos gets resized and thumbnailed, and stored on the server. At the same time, there are some INSERTS into a MySQL table regarding the photo uploaded (like description, user id etc). The site currently runs off a managed VPS, and I love the support it provides. However it is expensive to store the many small photos and the resizing and thumbnailing processes do cause spikes on the app performance. (Amazon S3 is pretty expensive, especially considering the costs for uploading many small files) Question: Will it be a good idea to move the image processing operations and image storage to another server which is an unmanaged dedicated server with a much lower cost/gb and keep the current VPS for its 24/7 support and hosting the webapp? Or should I move the entire site to the dedicated server? VPS Specs 16 cores 2.4GHz (E5620) 1GB memory 60GB Storage 3.5TB transfer $43/mth Managed (24/7) Dedicated Specs i3 2130 2 cores 3.4+ GHz 16 GB DDR3 2 x 1TB SATA2 storage 15 TB transfer $79/mth Unmanaged (Weekdays support) Software used Apache PHP MySQL Solr PostgreSQL ImageMagick

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  • Optimum number of threads while multitasking

    - by Gun Deniz
    I know similar questions have been asked but I think my case is a little bit diffrent. Let's say I have a computer with 8 cores and infinite memory with a Linux OS. I have a calculation software called Gaussian that can take advantage of multithreading. So I set its thread count to 8 for a single calculation for maximum speed. However I really can't decide what to do when I need to do run for instance 8 calculations simultaneously. In that case should I set the thread count to 1(total 8 threads spawned in 8 processes) or keep it 8(total 64 threads spawned in 8 processes) for each job? Does it really matter much? A related question is does the OS automatically does the core-parking to diffrent cores for each thread?

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  • Service haproxy error

    - by user128296
    I want to configure Haproxy for outgoing mail load balancing. my configuration file /etc/haproxy.cfg is. global maxconn 4096 # Total Max Connections. This is dependent on ulimit daemon nbproc 4 # Number of processing cores. Dual Dual-core Opteron is 4 cores for example. defaults mode tcp listen smtp_proxy 199.83.95.71:25 mode tcp option tcplog balance roundrobin # Load Balancing algorithm ## Define your servers to balance server r23.lbsmtp.org 74.117.x.x:25 weight 1 maxconn 512 check server r15.lbsmtp.org 199.71.x.x:25 weight 1 maxconn 512 check And when i start service haproxy i get this error. Starting HAproxy: [ALERT] 244/172148 (7354) : cannot bind socket for proxy smtp_proxy. Aborting. Please tell me where i am doing mistake.help will appreciated.

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  • System will only boot into a Live CD with core disabled in BIOS and ACPI off.

    - by CookieOfFortune
    I have a system that was running a Q6600 and Windows 7 RC. It crashed last night into a BSOD with a MACHINE_CHECK_EXCEPTION. Now it does that every time it boots into Windows. I tried using my Ubuntu Live CD, but the kernel would error out, the stack trace showed something along the linse of "Can not synchronized to one of the CPUs". Working from this, I enabled the "Limit CPU to 3 cores" option in my BIOS and tried again. This time, it seemed to have died after an ACPI call, so I disabled that during the boot and now it is running from the Ubuntu Live CD, showing 2 cores. Does anyone here think I have any hope or is it simply a CPU waiting to die? EDIT: 1 core now.

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  • Limit user to one CPU core in windows 7

    - by Dean Ward
    I let my family members use my pc over rdp to play their flash-based games as their laptops overheat if they use them directly. I have it setup so I can use the pc at the same time as them. The pc has a quad core cpu and I would like to be able to assign one of those cores to the user logged in via RDP so that the other 3 cores are left alone. Is this possible? They login via a specific user account setup for the purpose. Thanks for any advice!

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  • High load on a nagios server -- How many service checks for a nagios server is too many?

    - by Josh
    I have a nagios server running Ubuntu with a 2.0 GHz Intel Processor, a RAID10 array, and 400 MB of RAM. It monitors a total of 42 services across 8 hosts, most of which are checked using the check_http plugin even 5 minutes, some every minute. Recently the load on the nagios server has been above 4, often as high as 6. The server also runs cacti, gathering statistics every minute for 6 hosts. I wonder, how many services should hardware like this be able to handle? Is the load so high because I am pushing the limits of the hardware, or should this hardware be able to handle 42 service checks plus cacti? If the hardware is inadequate, should I look to add more RAM, more cores, or faster cores? What hardware / service checks are others running?

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  • Windows Server 2008 R2 Maximum Processor Limit Confusion

    - by Stevoni
    As I was looking through the Windows Server 2008 R2 specifications, I saw that the maximum supported processors is 64 sockets for Datacenter addition. This puts the maximum number or cores at 256 (if all sockets are quad cores), which I think it's just silly, but whatever. And now the questions: How does one set something like that up? (Obviously not for me, but humor me) Are there multiple dual socket motherboards running in a giant case with a ton of memory? How does the OS see all of the CPUs if they're on different boards? What would be a real world example of a need to have 64 sockets attached to one operating system vs 32 2 socket servers?

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  • Workstation Build: Single 2.66ghz i-7 with overclock potential, OR Dual 5520 2.26ghz Xeons?

    - by jdc0589
    There are probably better places to ask this, but I am used to the excellent quality of responses on stack overflow. I am rebuilding my desktop in a few months. Aside from normal lightweight internet usage, I use it to run sqlServer, mySql, 1-2 Ubuntu VMs from time to time, lots of IDE's, and a media server for my PS3. The two possible setups cost the exact same amount (within $50) and would both have 12gb 1333mhz ddr3 ram and a 500gb RAID-0 array (250x2). Now, If I go with a single i-7 920 2.66ghz quadcore, I can easily overclock it to 3ghz, and would have cash leftover to get a 160gb ssd (either the ocz vertex or the 120gb intel) for the main OS/Program install drive. Else, I could get a dual lga1366 motherboard with two e5520 Xeon's (2.26ghz),just use the disks I already have. So, do I go for 8 physical/16 virtual cores at 2.26ghz (No overclocking on server boards) with normal disk I/O, or a 4 physical/8 virtual cores at 3.0ghz with really outstanding disk I/O?

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  • Display CPU usage separately (without root privileges)

    - by synaptik
    I need to display the CPU usage for each processing core on a single shared-memory 12-core (SMP) machine. I don't have access to install htop, else I would simply use that. I don't need fancy graphs or meters, though they would be nice. For example, simply displaying: X X X X X X X X X X X X where each X is the percentage utilization of 1 of the 12 processing cores on my machine. FYI: I know I can simply look at the utilization in "top" and divide that number by the number of cores on my machine, but I prefer a solution that shows each core separately.

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  • Windows 2008 R2 on ESXi 4.1 cpu utilization kernel high

    - by MK.
    I have a Win2k8 guest running on ESXi 4.1. The host has 12 cores and the problem happens even if the guest is the only VM on the host. We have 4 cores dedicated to the guest. We noticed that network starts chocking when the CPU load goes up. After some testing we noticed that when running a simple CPU hogging tool set up to run 3 threads at 100% the regular CPU load goes to 75% like it should and the "kernel times" graph in task manager goes up to 25%. My intuition tells me that the network problem and kernel times problem are the same. This is confirmed by another similar VM we created on the same host which doesn't have either of the problems. VMWare tools are obviously installed. The nic is e1000. What else can we do to troubleshoot this?

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  • how can I estimate the conversion speed (fps) of a video based on CPU power? [closed]

    - by Ahoura Ghotbi
    Atm I am running a video sharing website and I am converting alot of videos. the queue is getting a bit too long (400 videos). I am planning on purchasing a new server and I was wondering if there anyway I can estimate the fps while converting 10 videos at the same time? Regards EXTRA INFO I am using MP4Box (which uses ffmpeg) to handle the encoding etc. Its encoding at 23 CRF, audio bitrate of 96 and audio sampling rate of 44100. The server will have the following processor : Dual Opteron 6272 (2 x 16 cores, 32 cores total) + 128GB RAM.

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  • Haproxy, configure for one host

    - by Michal K.
    I have to use haproxy on one machine. I want to do redirect requests from Ip to the same ip (with another port). My configuration (doesn't work): lobal maxconn 4096 # Total Max Connections. This is dependent on ulimit daemon nbproc 1 # Number of processing cores. Dual Dual-core Opteron is 4 cores for example. defaults mode http clitimeout 600000000 srvtimeout 600000000 contimeout 400000000 log 127.0.0.1 local0 log 127.0.0.1 local1 notice option httpclose # Disable Keepalive listen http_proxy 127.0.0.1:8080 balance leastconn # Load Balancing algorithm acl acl_apache path_end .avi .jpeg #option httpchk option forwardfor # This sets X-Forwarded-For ## Define your servers to balance server DE2 127.0.0.1:8080 weight 1 maxconn 15 check

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  • SQL SERVER – The Difference between Dual Core vs. Core 2 Duo

    - by pinaldave
    I have decided that I would not write on this subject until I have received a total of 25 questions on this subject. Here are a few questions from the list: Questions: What is the difference between Dual Core and Core 2 Duo? Which one is recommended for SQL Server: Core 2 Duo or Dual Core? Can I upgrade my Dual Core to Core 2 Duo? If Dual Core has 2 CPUs, how many CPUs does Core 2 Duo have? Is it true that Core 2 Duo and Dual Core meant the same thing? Well, let us see the answer. Optimistically, I would be directing everybody to this blog post if I receive a question of the same kind sometime in the future. To verify the information that I provide, visit Intel’s site. For additional information regarding the subject, visit Wikipedia. My Answer: Any computer that has two CPUs or two “cores“ is known as Dual Core. Core Duo is a brand name of Intel for Dual Core. Core 2 Duo is simply a higher version of Core Duo. (e.g. for Pentium brand, it`s like Pentium I, Pentium II, etc.) The computer I am using now has Core 2 Duo. Intel has launched a new brand, which they call i3, i5, and i7.  Here, the numbers are not related to the number of cores; rather, they show the range of the CPU. I3 is of low range and i7 is of high range. Feel free to add more details by adding valuable comments here. And if you still want to ask why I created this blog post, well, I mentioned that I was waiting for 25 questions threshold to hit, before I write about this subject which I didn`t really plan to write about. Reference: Pinal Dave (http://blog.SQLAuthority.com) Filed under: Pinal Dave, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, SQLAuthority News, T SQL, Technology

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  • Game Changer Appliance for SMBs Powered by Oracle Linux

    - by Zeynep Koch
    In the November 28th CRN article  Review: Thumbs-Up On Oracle Database Appliance  , Edward F. Moltzen mentions that "The Test Center likes this appliance (Oracle Database Appliance) , for the performance and for the strong security offered by the underlying Oracle Linux in the box. It’s more than a solid offering for the SMB space; it’s potentially a game-changer as data and security needs race to keep up with the oncoming generations of technology." The Oracle Database Appliance is a new way to take advantage of the world's most popular database—Oracle Database 11g—in a single, easy-to-deploy and manage system. It's a complete package of software, server, storage, and network that's engineered for simplicity; saving time and money by simplifying deployment, maintenance, and support of database workloads. All hardware and software components are supported by a single vendor—Oracle—and offer customers unique pay-as-you-grow software licensing to quickly scale from 2 processor cores to 24 processor cores without incurring the costs and downtime usually associated with hardware upgrades. It is: Simple—Complete plug-and-go hardware and software Reliable—Advanced management features and single-vendor support Affordable—Pay-as-you-grow platform for small database consolidation The Oracle Database Appliance is a 4U rack-mountable system pre-installed with Oracle Linux and Oracle appliance manager software. Redundancy is built into all components and the Oracle appliance manager software reduces the risk and complexity of deploying highly available databases. It's perfect for consolidating OLTP and data warehousing databases up to 4 terabytes in size, making it ideal for midsize companies or departmental systems. Read more about Oracle's Database Appliance  Read more about Oracle Linux

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  • My processor is not detected intel core 2 duo

    - by walid
    My processor is not detected intel core 2 duo When I type $uname -m -p I get this i686 unknown I have Ubuntu 10.10 netbook remix but the cat /proc/cpuinfo gives right identification of two processors as below processor : 0 vendor_id : GenuineIntel cpu family : 6 model : 15 model name : Intel(R) Core(TM)2 CPU T5600 @ 1.83GHz stepping : 6 cpu MHz : 1826.000 cache size : 2048 KB physical id : 0 siblings : 2 core id : 0 cpu cores : 2 apicid : 0 initial apicid : 0 fdiv_bug : no hlt_bug : no f00f_bug : no coma_bug : no fpu : yes fpu_exception : yes cpuid level : 10 wp : yes flags : fpu vme de pse tsc msr pae mce cx8 apic mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe nx lm constant_tsc arch_perfmon pebs bts aperfmperf pni dtes64 monitor ds_cpl vmx est tm2 ssse3 cx16 xtpr pdcm lahf_lm dts tpr_shadow bogomips : 3657.99 clflush size : 64 cache_alignment : 64 address sizes : 36 bits physical, 48 bits virtual power management: processor : 1 vendor_id : GenuineIntel cpu family : 6 model : 15 model name : Intel(R) Core(TM)2 CPU T5600 @ 1.83GHz stepping : 6 cpu MHz : 1826.000 cache size : 2048 KB physical id : 0 siblings : 2 core id : 1 cpu cores : 2 apicid : 1 initial apicid : 1 fdiv_bug : no hlt_bug : no f00f_bug : no coma_bug : no fpu : yes fpu_exception : yes cpuid level : 10 wp : yes flags : fpu vme de pse tsc msr pae mce cx8 apic mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe nx lm constant_tsc arch_perfmon pebs bts aperfmperf pni dtes64 monitor ds_cpl vmx est tm2 ssse3 cx16 xtpr pdcm lahf_lm dts tpr_shadow bogomips : 3657.53 clflush size : 64 cache_alignment : 64 address sizes : 36 bits physical, 48 bits virtual power management: The problem is with programs that uses more than one core like virtualbox and bitcoin which refuses to use more than one core Is there anythign wrong or anything that I can do? My installation is from a live usb iso on a USB

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  • The Fantastic New WebLogic on Oracle Database Appliance 2.9 Release is Here!

    - by JuergenKress
    Last week was a big day in virtualised ODA-land as it saw the launch of WebLogic on ODA 2.9. Admittedly it doesn't sound like a very exciting release but it is one that we at O-box have been looking forward to for quite some time. Let me explain why, then we'll look into the details... The ODA X4-2 has 48 Intel Xeon cores. That is a lot of compute power. Whilst the largest O-box SOA Appliance single environment configuration can in theory use all those cores (currently with 40 vCPU of SOA!) the vast majority of O-box users will want smaller configurations. Prior to 2.9 the Oracle WebLogic implementation only supported one domain per ODA, so the conundrum O-box development faced last year was either: offer customers only one SOA environment on their O-box for now (but have the benefit of a standard, easily supportable WebLogic installation), or build our own WebLogic/OTD OVM templates from scratch. One of our driving goals with O-box is to give the best possible experience and make the appliance as supportable as possible. Therefore we took the gamble that we would stick with the Oracle's one-domain WebLogic configuration initially, and just hope that it would deliver multi-domain support for us in a timely manner (note: this is probably not a strategy that business textbooks would recommend!). Anyway, we've been working closely with Oracle Product Management for a few months now and I'm delighted to see 2.9 as the fruits of their labour. This also neatly ties in with several recent requests for O-box to include OSB as well as SOA/BPEL (which we have always wanted to have in separate domains). The diagram below is the neatest way to summarise what the new 2.9 release will allow us to deliver, i.e. previously only one 3D box was possible: Read the complete article here. WebLogic Partner Community For regular information become a member in the WebLogic Partner Community please visit: http://www.oracle.com/partners/goto/wls-emea ( OPN account required). If you need support with your account please contact the Oracle Partner Business Center. Blog Twitter LinkedIn Mix Forum Wiki Technorati Tags: oBox,WebLogic on ODA,ODA,WebLogic,WebLogic Community,Oracle,OPN,Jürgen Kress

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  • Fix for poor hd playback for 11.04 upwards

    - by mark kirby
    Hi guys ive seen loads of posts on this site about poor 720/1080p playback in recent ubuntu versions I had this problem and fixed it so I thought id share it with everyone.... 1 install mplayer 2 install smplayer frontend {in software center} 3 open smplayer 4 go to "OPTIONS" then "PREFRENCES" then "GENRAL" 5 if you have a nvidia card choose "OUTPUT DRIVER" and select "VDPAU" {for ATI or AMD choose xv (0 - ATI Radeon AVIVO video) I dont know if this will work as my card is nvidia but it should) 6 go to performance on the left hand side and set both local and streaming cache to 99999 (this may also fix dvd playback if you set that cache aswell} 7 check the box for "ALLOW HARD FRAME DROP" and set "LOOP FILTER" to skip only on HD 8 Set the "THREDS FOR DECODING OPTION TO THE NUMBER OF CORES YOUR CPU HAS IF YOU HAVE MORE THAN ONE CPU ADD UP ALL THE CORES FOR BEST PERFORMANCE" 9 Enjoy you HD movies again on ubuntu...... I have a pretty avrage machine heres my spec.... 2x Pentium 4 ht 3 ghz Stock dell power and motherboard GFORCE 310 HDMI 24 inch full HD tv as a monitor so any one with dule core cpu should have no problems getting this to work. hope this helps someone out.

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  • Ubuntu server 11.04 recognize only 1 core instead of 4

    - by Kreker
    I searched for other questions and googled a lot but I don't find a solution for solving this problem. Ubuntu Server 11.04 64bit installed on Dell Poweredge with Intel Xeon X5450. He only recognize 1 of the 4 cores I have. Tried to modify the GRUB config but didn't work. IN the machine BIOS I didn't find anything useful. CPU root@darwin:~# cat /proc/cpuinfo processor : 0 vendor_id : GenuineIntel cpu family : 6 model : 23 model name : Intel(R) Xeon(R) CPU X5450 @ 3.00GHz stepping : 10 cpu MHz : 2992.180 cache size : 6144 KB physical id : 0 siblings : 1 core id : 0 cpu cores : 1 apicid : 0 initial apicid : 0 fpu : yes fpu_exception : yes cpuid level : 13 wp : yes flags : fpu vme de pse tsc msr pae mce cx8 sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe syscall nx lm constant_tsc arch_perfmon pebs bts rep_good nopl aperfmperf pni dtes64 monitor ds_cpl vmx est tm2 ssse3 cx16 xtpr pdcm dca sse4_1 xsave lahf_lm dts tpr_shadow vnmi flexpriority bogomips : 5984.36 clflush size : 64 cache_alignment : 64 address sizes : 38 bits physical, 48 bits virtual power management: GRUB root@darwin:~# cat /etc/default/grub # If you change this file, run 'update-grub' afterwards to update # /boot/grub/grub.cfg. # For full documentation of the options in this file, see: # info -f grub -n 'Simple configuration' GRUB_DEFAULT=0 #GRUB_HIDDEN_TIMEOUT=0 GRUB_HIDDEN_TIMEOUT_QUIET=true GRUB_TIMEOUT=2 GRUB_DISTRIBUTOR=`lsb_release -i -s 2> /dev/null || echo Debian` GRUB_CMDLINE_LINUX_DEFAULT="" GRUB_CMDLINE_LINUX="noapic nolapic" #was with acpi=off # Uncomment to enable BadRAM filtering, modify to suit your needs # This works with Linux (no patch required) and with any kernel that obtains # the memory map information from GRUB (GNU Mach, kernel of FreeBSD ...) #GRUB_BADRAM="0x01234567,0xfefefefe,0x89abcdef,0xefefefef" # Uncomment to disable graphical terminal (grub-pc only) #GRUB_TERMINAL=console # The resolution used on graphical terminal # note that you can use only modes which your graphic card supports via VBE # you can see them in real GRUB with the command `vbeinfo' #GRUB_GFXMODE=640x480 # Uncomment if you don't want GRUB to pass "root=UUID=xxx" parameter to Linux #GRUB_DISABLE_LINUX_UUID=true # Uncomment to disable generation of recovery mode menu entries #GRUB_DISABLE_RECOVERY="true" # Uncomment to get a beep at grub start #GRUB_INIT_TUNE="480 440 1" Complete dmesg Too long, posted on pastebin http://pastebin.com/bsKPBhzu

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  • Essbase Analytics Link (EAL) - Performance of some operation of EAL could be improved by tuning of EAL Data Synchronization Server (DSS) parameters

    - by Ahmed Awan
    Generally, performance of some operation of EAL (Essbase Analytics Link) could be improved by tuning of EAL Data Synchronization Server (DSS) parameters. a. Expected that DSS machine will be 64-bit machine with 4-8 cores and 5-8 GB of RAM dedicated to DSS. b. To change DSS configuration - open EAL Configuration Tool on DSS machine.     ->Next:     and define: "Job Units" as <Number of Cores dedicated to DSS> * 1.5 "Max Memory Size" (if this is 64-bit machine) - ~1G for each Job Unit. If DSS machine is 32-bit - max memory size is 2600 MB. "Data Store Size" - depends on number of bridges and volume of HFM applications, but in most cases 50000 MB is enough. This volume should be available in defined "Data Store Dir" driver.   Continue with configuration and finish it. After that, DSS should be restarted to take new definitions.  

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  • I have an "amoeba" game mechanic. Any idea on how to implement it?

    - by Jason
    Outside of a tetris clone, a crappy 2D top-down shooter, and some messing around with stuff like Unity and Flixel, I realize that I have yet to complete a single, polished, bells-and-whistles game. I want to change this, and I have an idea for my next project. The idea is that you're an amoeba. Amoebas have these eye-like cores (or something like that, I don't know biology), and you have two of 'em. You control one with WASD and the other with IJKL. There has to be a constant radius of stuff around each of the cores: And the area of the amoeba has to stay constant. So if you move a core in one direction, you increase the amoeba's area, but that increase is compensated by a decrease somewhere else: Aaaaaand I'd like to implement a vagination mechanic. You absorb things by engulfing them, like a boss. Maybe even an extra core, or a needle that pops you and causes all your inner stuff to start gushing out: But here's the problem: I don't know how to make this. However, I would like some ideas on how to implement it. Should I explore physics libraries like Box2D? Or maybe something involving fluid physics? Any help would be much appreciated. P.S. Feel free to steal this idea. I have plenty of ideas. If you do, please tell me how you made it so I can try it myself.

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  • Context switches much slower in new linux kernels

    - by Michael Goldshteyn
    We are looking to upgrade the OS on our servers from Ubuntu 10.04 LTS to Ubuntu 12.04 LTS. Unfortunately, it seems that the latency to run a thread that has become runnable has significantly increased from the 2.6 kernel to the 3.2 kernel. In fact the latency numbers we are getting are hard to believe. Let me be more specific about the test. We have a program that has two threads. The first thread gets the current time (in ticks using RDTSC) and then signals a condition variable once a second. The second thread waits on the condition variable and wakes up when it is signaled. It then gets the current time (in ticks using RDTSC). The difference between the time in the second thread and the time in the first thread is computed and displayed on the console. After this the second thread waits on the condition variable once more. So, we get a thread to thread signaling latency measurement once a second as a result. In linux 2.6.32, this latency is somewhere on the order of 2.8-3.5 us, which is reasonable. In linux 3.2.0, this latency is somewhere on the order of 40-100 us. I have excluded any differences in hardware between the two host hosts. They run on identical hardware (dual socket X5687 {Westmere-EP} processors running at 3.6 GHz with hyperthreading, speedstep and all C states turned off). We are changing the affinity to run both threads on physical cores of the same socket (i.e., the first thread is run on Core 0 and the second thread is run on Core 1), so there is no bouncing of threads on cores or bouncing/communication between sockets. The only difference between the two hosts is that one is running Ubuntu 10.04 LTS with kernel 2.6.32-28 (the fast context switch box) and the other is running the latest Ubuntu 12.04 LTS with kernel 3.2.0-23 (the slow context switch box). Have there been any changes in the kernel that could account for this ridiculous slow down in how long it takes for a thread to be scheduled to run?

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  • Ubuntu 11 and 12 initially fast but later bogs down, CPU pegged

    - by uos??
    I started with Ubuntu 11 a few weeks ago. It's on a DELL M4300 with a OCZ SSD. Default setup, except that I've installed the proprietary NVIDIA graphics and BROADCOM wireless drivers. Dual boot with Windows. If I cold boot into Ubuntu, it is very fast, just like the Windows experience that I'm used to. But SOMETHING happens, and I haven't yet determined what, but the system gets incredibly slow and stays that way. At first I thought it had to do with Adobe Flash because it seemed to be triggered by sites with Flash. But then I removed Flash and the problem remains. I thought it was just an overheating problem, but I've now upgraded to 12.04 which supposedly fixes the overheating problems I've read about. Perhaps the heat situation was brought on by Flash in my early cases? So I installed Jupiter for CPU management, but the thermometer reports a familiar Windows-side temperature of 53 degrees Celsius. Switching Jupiter to lower performance doesn't help. When I check the System Monitor application, sorting by CPU usage, there are no obvious problem processes. However, in the graphs tab, both CPU cores are pegged at 100%! I notice that the slowness seems to be similar to the extremely bad performance I got prior to installing the NVIDIA drivers. I'm not sure if that helps. This is the strangest part to me - although the temperature seems OK, even after rebooting, the system remains slow - starting with GRUB2 which is very noticeably delayed, all the way through to either Ubuntu or Windows! That's right, even the Windows side suffers effects and takes several minutes to complete booting whereas normally (with my SSD) it's ready to use in 15 seconds. The only way to fix it is to shutdown and let the parts cool down. Or maybe it just needs to completely power off and boot rather than a soft reboot, temperature has nothing to do with it? - is that possible? But know that I have never had this problem in Windows, even if Windows gets very hot (135 F) a reboot would be enough time for it to recover. For this reason, I don't think it's a heat thing, but I can't imagine what else could be surviving the reboot. I'm entirely updated - there are no pending updates. I have the Post-Release updates of NVIDIA too, btw. If this sounds CLOSE to something you know about, but one of the details doesn't line up exactly, it might be a mistake in my perception. Are there tests you can suggest to rule something out? Thanks! processor : 0 vendor_id : GenuineIntel cpu family : 6 model : 23 model name : Intel(R) Core(TM)2 Duo CPU T9500 @ 2.60GHz stepping : 6 microcode : 0x60c cpu MHz : 800.000 cache size : 6144 KB physical id : 0 siblings : 2 core id : 0 cpu cores : 2 apicid : 0 initial apicid : 0 fpu : yes fpu_exception : yes cpuid level : 10 wp : yes flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe syscall nx lm constant_tsc arch_perfmon pebs bts rep_good nopl aperfmperf pni dtes64 monitor ds_cpl vmx est tm2 ssse3 cx16 xtpr pdcm sse4_1 lahf_lm ida dts tpr_shadow vnmi flexpriority bogomips : 5187.00 clflush size : 64 cache_alignment : 64 address sizes : 36 bits physical, 48 bits virtual power management: processor : 1 vendor_id : GenuineIntel cpu family : 6 model : 23 model name : Intel(R) Core(TM)2 Duo CPU T9500 @ 2.60GHz stepping : 6 microcode : 0x60c cpu MHz : 800.000 cache size : 6144 KB physical id : 0 siblings : 2 core id : 1 cpu cores : 2 apicid : 1 initial apicid : 1 fpu : yes fpu_exception : yes cpuid level : 10 wp : yes flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe syscall nx lm constant_tsc arch_perfmon pebs bts rep_good nopl aperfmperf pni dtes64 monitor ds_cpl vmx est tm2 ssse3 cx16 xtpr pdcm sse4_1 lahf_lm ida dts tpr_shadow vnmi flexpriority bogomips : 5186.94 clflush size : 64 cache_alignment : 64 address sizes : 36 bits physical, 48 bits virtual power management: (Redundant figures removed. You can view them in the edits if they are still relevant) ps: %CPU PID USER COMMAND 9.4 2399 jason gnome-terminal 6.2 2408 jason bash 17.3 1117 root /usr/bin/X :0 -auth /var/run/lightdm/root/:0 -nolisten tcp vt7 -novtswitch -background none 13.7 1667 jason compiz 1.3 1960 jason /usr/lib/unity/unity-panel-service 1.3 1697 jason python /usr/bin/jupiter 0.9 1964 jason /usr/lib/indicator-appmenu/hud-service 0.6 1689 jason nautilus -n 0.4 1458 jason //bin/dbus-daemon --fork --print-pid 5 --print-address 7 --session I should highlight specifically that GRUB2 can also be very slow. I don't know the relationship of which scenarios GRUB2 is also slow, but WHEN it is slow, it is slow both before the menu appears and after the selection is made - although for the diagnosis of GRUB2 it is harder for me to tell what the normal speeds should be. With SSD, I would expect that GRUB2 could load instantly, and that the GRUB2 purple would disappear instantly after the selection. The only delay to be expected is the change in graphics modes (though I couldn't guess why that ever requires any noticeable time)

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