Search Results

Search found 14861 results on 595 pages for 'high speed computing'.

Page 38/595 | < Previous Page | 34 35 36 37 38 39 40 41 42 43 44 45  | Next Page >

  • In search of a network file system with extended caching to speed up file access

    - by Brecht Machiels
    I'm running a small home server that stores my documents. The disks in this server are in a RAID 1 configuration (using Linux md) and it's also periodically being backup up to an external hard drive to make sure I don't lose them. However, I'm always accessing the files from other computers on the home network using an SMB share, and this results in a considerable speed penalty (especially when connected over WLAN). This is quite annoying when editing large files, such as digital camera RAWs, for example. I've been looking for a solution to this problem. It would have to offer some kind of local caching to speed up the file access. The client would preferably not keep a copy of all data on the server, as it consists of a very large collection of photographs, most of which I will not access frequently. Instead, it should only cache the accessed files and sync the changes back in the background. Ideally, it would also do some smart read-ahead (cache the files that are in the same directory as the currently opened file, for examples), but I suppose that's asking a bit much. Synchronization should be automatic (on file change). Conflicting file changes (at the same time on different clients) are unlikely to happen in my use case, but I would prefer if they are handled properly (notification to the user). I've come across the following options, so far: something similar to Dropbox. iFolder seems to be the only thing that comes close, but its reputation (stability) and requirements put me off. A distributed file system such as OpenAFS. I'm not sure this will speed up file access. It is probably overkill for what I need. Maybe NFS or even Samba offer these possibilities. I read a bit about Windows' Offline Files, but its operation seems limited (at least on Windows XP). As this is just for personal use, I'm not willing to spend a lot of money. A free solution would be preferred. Also, the server needs to run on Linux, and I need a client for at least Windows.

    Read the article

  • how I can Specifying tcpreplay speed

    - by herzl shemuelian
    I am tring to Specify tcpreplay speed but I can't do it this is my detail of test: $tcpreplay -V tcpreplay version: 3.4.4 (build 2450) 1)$ tcpreplay -i %0 -p 100 -L 500 _udp_only.pcap Actual: 500 packets (42247 bytes) sent in 5.05 seconds.Rated: 8365.7 bps, 0.06 Mbps, 99.01 pps s 2)$ tcpreplay -i %0 -p 1000 -L 5000 _udp_only.pcap Actual: 5000 packets (427710 bytes) sent in 5.19 seconds. Rated: 82410.4 bps, 0.63 Mbps, 963.39 pps //here is problem I stay in 966.00 pps 3)$ tcpreplay -i %0 -p 10000 -L 50000 _udp_only.pcap Actual: 50000 packets (4322559 bytes) sent in 51.76 seconds.Rated: 83511.6 bps, 0.64 Mbps, 966.00 pps I have same problem when I try to Specify --mbps for 8600 packets 86 byte avg for each packet -M0.086 -L 860 ---- Rated: 10812.9 bps, 0.08 Mbps, 127.22 pps -M0.86 -L 860 ---- Rated: 83062.5 bps, 0.63 Mbps, 977.27 pps -M0.86 -L 8600 ---- Rated: 82554.9 bps, 0.63 Mbps, 965.21 pps why and how I can to Specify speed? I use OS windows7

    Read the article

  • my torrent speed is slower all of the sudden

    - by nazmi98
    Last year when I tried to download torrent the speed was around 120 kb/s, but now it's only 10 kbs/s. I'm really confused here. I have been trying everything that I could find on the internet but nothing seems to work, so I'm really desperate for help. One more thing: I don't know if this will help, but i'm from Malaysia. My internet speed is 1 mb. I tried using all the PCs that I own and all seems to produce the same result.

    Read the article

  • Database Server Hardware components (order of importance), CPU speed VS CPU cache vs RAM vs DISK

    - by nulltorpedo
    I am new to database world and would like to know what are crucial hardware specs when it comes to database performance. I have searched the internet and found this so far (In order of decreasing importance): 1) Hard Disk: Get an SSD basically (much more IOPS than spinners) 2) Memory: Get as much as you can afford 3) CPU: For the same $ spent, prefer larger cache size over speed. Are these findings sensible? EDIT: I would like to focus on CPU speed VS CPU cache size. EDIT2: The database is used to store some combination of ints and int arrays with few text fields. There are a lot of Select queries looking for existing entries. If entry is not found, then insert it. I would say most of processing would be trying to find a match across a table with 200 columns and 20k rows. The insert statements are very few. EDIT3: Also, we have a lot of views (basically select queries).

    Read the article

  • Finding optimal ddrescue command line options where Accuracy > Speed

    - by gav
    I'm read up a bit about this tool and obviously looked at the man pages. The trouble is that ddrescue takes so long I need to get the command right first time. I wasn't sure how to improve on the vanilla; $ sudo ./ddrescue -v /dev/disk0s5 MyVolImage.dmg MyVolRescue.log $ sudo ./ddrescue -v MyVolImage.dmg /dev/disk1s3 MyVolRestore.log From HSF+ to HSF+ drives Source (Broken) HDD is connected via USB 2.0 Dest HDD is inside MacBook I would choose accuracy over speed There seem to be a lot of options but I'm not sure how they impact quality and speed of recovery. Thanks, Gav

    Read the article

  • Un-balanced network speed although using fiberoptic cable line

    - by Hoàng Long
    I'm not sure this is a right place to ask this question, but there's a strange thing that I don't quite sure what the reason is. My company has hired a fiberoptic cable line for network use (Wifi and cable through a router). But the strange thing is that, whenever someone view YouTube or listen stream music, then network speed for all the others become extremely slow. The download speed for that person is about 4-5 MB/s (or more), but others suffer. I'm still a newbie about networking. But I know there should be a solution. Could anyone tell me a way to stop this bad behavior? It's not possible for asking people not viewing YouTube, since that's part of their jobs. Any insights about this problem would be very welcome.

    Read the article

  • low speed web application, Server problem or Application

    - by Ashian
    Hi, I have a web application written by asp.net (c#) sql server 2005. we host it on 2 dedicated server ( IIS and SQL server ) From some month ago , in some days of week we have many reports about speed issue. we have some other application on this server using same database. when we have speed problem all aplication on these server have this problem, but applications on other server in same data center work correctly. ram and cpu usage are ok. how can I check that the problem related to internet connection or my application design? which parameters must be checked. Some other information In applications users can upload several files to server , each file up to 3 MB. we use a sql web admin application, on same server that has same problem, this is a standard application which work perfectly on other servers. Thanks

    Read the article

  • Data transfer speed to USB storage connected to wifi router very slow

    - by RonakG
    Here is my setup. A Linksys Cisco E3200 wifi router. A MacbookPro running OS X Lion 10.7.4. A Seagate GoFlex 1TB hard drive connected to wifi router via the USB port. When I try to transfer data from my MBP to the HDD, the data transfer rate is very low. I'm getting around 3MB/s write speed. This is very slow compared to the speed I get when HDD is directly connected to the MBP. The HDD is NTFS formatted. And the router provides access to HDD using Samba share. So I connect to the HDD using smb://. What is the limiting factor here affecting the data transfer rate?

    Read the article

  • Persian font in Netbeans cause speed reduction

    - by linker
    I have speed problem in Netbeans 7.0 IDE when my current open document has any Persian font inside it. If it happens, the speed of software incredibly reduce.( for example if I hit backspace, it takes about 10 seconds to respond). The amazing part is when I open a fully english document in Netbeans there is no problem and everything works well. I'm running netbeans 7.0 on Mac OS X 10.7.2. This problem happens with every fonts( even with fully Persian fonts). But I really want to have Persian with default Monospaced font. Thanks in advance.

    Read the article

  • Cloud security and privacy

    - by Rakesh K
    Hi, I have a very basic doubt regarding cloud computing that is catching up pretty fast these days. To my understanding, cloud computing is a paradigm in which companies put up their data and applications on somebody else's machines aka 'The Cloud'. I want to know just how secure is it to put up my data on some third party machines, especially if my data contains private details. In particular, how can an enterprise trust the cloud computing service providers in this data privacy aspect? Thanks, rakesh.

    Read the article

  • Using TPL and PLINQ to raise performance of feed aggregator

    - by DigiMortal
    In this posting I will show you how to use Task Parallel Library (TPL) and PLINQ features to boost performance of simple RSS-feed aggregator. I will use here only very basic .NET classes that almost every developer starts from when learning parallel programming. Of course, we will also measure how every optimization affects performance of feed aggregator. Feed aggregator Our feed aggregator works as follows: Load list of blogs Download RSS-feed Parse feed XML Add new posts to database Our feed aggregator is run by task scheduler after every 15 minutes by example. We will start our journey with serial implementation of feed aggregator. Second step is to use task parallelism and parallelize feeds downloading and parsing. And our last step is to use data parallelism to parallelize database operations. We will use Stopwatch class to measure how much time it takes for aggregator to download and insert all posts from all registered blogs. After every run we empty posts table in database. Serial aggregation Before doing parallel stuff let’s take a look at serial implementation of feed aggregator. All tasks happen one after other. internal class FeedClient {     private readonly INewsService _newsService;     private const int FeedItemContentMaxLength = 255;       public FeedClient()     {          ObjectFactory.Initialize(container =>          {              container.PullConfigurationFromAppConfig = true;          });           _newsService = ObjectFactory.GetInstance<INewsService>();     }       public void Execute()     {         var blogs = _newsService.ListPublishedBlogs();           for (var index = 0; index <blogs.Count; index++)         {              ImportFeed(blogs[index]);         }     }       private void ImportFeed(BlogDto blog)     {         if(blog == null)             return;         if (string.IsNullOrEmpty(blog.RssUrl))             return;           var uri = new Uri(blog.RssUrl);         SyndicationContentFormat feedFormat;           feedFormat = SyndicationDiscoveryUtility.SyndicationContentFormatGet(uri);           if (feedFormat == SyndicationContentFormat.Rss)             ImportRssFeed(blog);         if (feedFormat == SyndicationContentFormat.Atom)             ImportAtomFeed(blog);                 }       private void ImportRssFeed(BlogDto blog)     {         var uri = new Uri(blog.RssUrl);         var feed = RssFeed.Create(uri);           foreach (var item in feed.Channel.Items)         {             SaveRssFeedItem(item, blog.Id, blog.CreatedById);         }     }       private void ImportAtomFeed(BlogDto blog)     {         var uri = new Uri(blog.RssUrl);         var feed = AtomFeed.Create(uri);           foreach (var item in feed.Entries)         {             SaveAtomFeedEntry(item, blog.Id, blog.CreatedById);         }     } } Serial implementation of feed aggregator downloads and inserts all posts with 25.46 seconds. Task parallelism Task parallelism means that separate tasks are run in parallel. You can find out more about task parallelism from MSDN page Task Parallelism (Task Parallel Library) and Wikipedia page Task parallelism. Although finding parts of code that can run safely in parallel without synchronization issues is not easy task we are lucky this time. Feeds import and parsing is perfect candidate for parallel tasks. We can safely parallelize feeds import because importing tasks doesn’t share any resources and therefore they don’t also need any synchronization. After getting the list of blogs we iterate through the collection and start new TPL task for each blog feed aggregation. internal class FeedClient {     private readonly INewsService _newsService;     private const int FeedItemContentMaxLength = 255;       public FeedClient()     {          ObjectFactory.Initialize(container =>          {              container.PullConfigurationFromAppConfig = true;          });           _newsService = ObjectFactory.GetInstance<INewsService>();     }       public void Execute()     {         var blogs = _newsService.ListPublishedBlogs();                var tasks = new Task[blogs.Count];           for (var index = 0; index <blogs.Count; index++)         {             tasks[index] = new Task(ImportFeed, blogs[index]);             tasks[index].Start();         }           Task.WaitAll(tasks);     }       private void ImportFeed(object blogObject)     {         if(blogObject == null)             return;         var blog = (BlogDto)blogObject;         if (string.IsNullOrEmpty(blog.RssUrl))             return;           var uri = new Uri(blog.RssUrl);         SyndicationContentFormat feedFormat;           feedFormat = SyndicationDiscoveryUtility.SyndicationContentFormatGet(uri);           if (feedFormat == SyndicationContentFormat.Rss)             ImportRssFeed(blog);         if (feedFormat == SyndicationContentFormat.Atom)             ImportAtomFeed(blog);                }       private void ImportRssFeed(BlogDto blog)     {          var uri = new Uri(blog.RssUrl);          var feed = RssFeed.Create(uri);           foreach (var item in feed.Channel.Items)          {              SaveRssFeedItem(item, blog.Id, blog.CreatedById);          }     }     private void ImportAtomFeed(BlogDto blog)     {         var uri = new Uri(blog.RssUrl);         var feed = AtomFeed.Create(uri);           foreach (var item in feed.Entries)         {             SaveAtomFeedEntry(item, blog.Id, blog.CreatedById);         }     } } You should notice first signs of the power of TPL. We made only minor changes to our code to parallelize blog feeds aggregating. On my machine this modification gives some performance boost – time is now 17.57 seconds. Data parallelism There is one more way how to parallelize activities. Previous section introduced task or operation based parallelism, this section introduces data based parallelism. By MSDN page Data Parallelism (Task Parallel Library) data parallelism refers to scenario in which the same operation is performed concurrently on elements in a source collection or array. In our code we have independent collections we can process in parallel – imported feed entries. As checking for feed entry existence and inserting it if it is missing from database doesn’t affect other entries the imported feed entries collection is ideal candidate for parallelization. internal class FeedClient {     private readonly INewsService _newsService;     private const int FeedItemContentMaxLength = 255;       public FeedClient()     {          ObjectFactory.Initialize(container =>          {              container.PullConfigurationFromAppConfig = true;          });           _newsService = ObjectFactory.GetInstance<INewsService>();     }       public void Execute()     {         var blogs = _newsService.ListPublishedBlogs();                var tasks = new Task[blogs.Count];           for (var index = 0; index <blogs.Count; index++)         {             tasks[index] = new Task(ImportFeed, blogs[index]);             tasks[index].Start();         }           Task.WaitAll(tasks);     }       private void ImportFeed(object blogObject)     {         if(blogObject == null)             return;         var blog = (BlogDto)blogObject;         if (string.IsNullOrEmpty(blog.RssUrl))             return;           var uri = new Uri(blog.RssUrl);         SyndicationContentFormat feedFormat;           feedFormat = SyndicationDiscoveryUtility.SyndicationContentFormatGet(uri);           if (feedFormat == SyndicationContentFormat.Rss)             ImportRssFeed(blog);         if (feedFormat == SyndicationContentFormat.Atom)             ImportAtomFeed(blog);                }       private void ImportRssFeed(BlogDto blog)     {         var uri = new Uri(blog.RssUrl);         var feed = RssFeed.Create(uri);           feed.Channel.Items.AsParallel().ForAll(a =>         {             SaveRssFeedItem(a, blog.Id, blog.CreatedById);         });      }        private void ImportAtomFeed(BlogDto blog)      {         var uri = new Uri(blog.RssUrl);         var feed = AtomFeed.Create(uri);           feed.Entries.AsParallel().ForAll(a =>         {              SaveAtomFeedEntry(a, blog.Id, blog.CreatedById);         });      } } We did small change again and as the result we parallelized checking and saving of feed items. This change was data centric as we applied same operation to all elements in collection. On my machine I got better performance again. Time is now 11.22 seconds. Results Let’s visualize our measurement results (numbers are given in seconds). As we can see then with task parallelism feed aggregation takes about 25% less time than in original case. When adding data parallelism to task parallelism our aggregation takes about 2.3 times less time than in original case. More about TPL and PLINQ Adding parallelism to your application can be very challenging task. You have to carefully find out parts of your code where you can safely go to parallel processing and even then you have to measure the effects of parallel processing to find out if parallel code performs better. If you are not careful then troubles you will face later are worse than ones you have seen before (imagine error that occurs by average only once per 10000 code runs). Parallel programming is something that is hard to ignore. Effective programs are able to use multiple cores of processors. Using TPL you can also set degree of parallelism so your application doesn’t use all computing cores and leaves one or more of them free for host system and other processes. And there are many more things in TPL that make it easier for you to start and go on with parallel programming. In next major version all .NET languages will have built-in support for parallel programming. There will be also new language constructs that support parallel programming. Currently you can download Visual Studio Async to get some idea about what is coming. Conclusion Parallel programming is very challenging but good tools offered by Visual Studio and .NET Framework make it way easier for us. In this posting we started with feed aggregator that imports feed items on serial mode. With two steps we parallelized feed importing and entries inserting gaining 2.3 times raise in performance. Although this number is specific to my test environment it shows clearly that parallel programming may raise the performance of your application significantly.

    Read the article

  • Le cloud computing pourrait faire gagner 763 milliards d'euros à l'Europe, et générer la création de 2.4 millions d'emplois

    Le cloud computing pourrait faire gagner 763 milliards d'euros à l'Europe, et générer la création de 2.4 millions d'emplois Nos voisins d'outre-manche viennent de publier une étude très intéressante. Elle révèle ainsi qu'une adoption majeure du cloud computing en Europe pourrait avoir des conséquences extrêmement positives pour l'économie. Une utilisation de masse de cette technologie permettrait aux pays de l'Union d'économiser 763 milliards d'euros sur cinq ans ! En effet, cela éviterait aux entreprises d'avoir à créer toutes leurs infrastructures IT. A la place, elles auraient juste à louer divers services et stockages. Le cloud computing permet aussi de réaliser des économies d'énergie, et si son prix parait enc...

    Read the article

  • How to see if turbo boost is working on I7 860 CPU?

    - by Jan Derk
    I just build myself a new system with a Intel I7 860 CPU. When loading it using a single threaded application like Super PI, CPU-Z shows 2.933Ghz as speed. Now I understood that the I7 goes into turbo boost mode up to 3.46GHz for a single core. How can I check that? Is there a utility to monitor CPU speed per core?

    Read the article

  • can router configuration cause decreasing of download rate?

    - by behrooz
    My download speed got crazy since I changed the router's IP. But nothing got fixed after doing a factory reset. The speed was 1024 kb/s (128 kB/s) but it is 200kb/s (max) right now. I mean it works good if a request is small (i.e. a HTTP request) but it gets slow if a request has a big response. Help me please. (It is three days I'm downloading VS2010.)

    Read the article

  • NAS Performance issus

    - by Markus
    I have bougth a NAS from Conecptronic CH3MNAS and build in two Western Digital 1,5TB Green Drives. I only get a write speed of 6mb/s in LAN The configuration of the drives is as follows: - Raid 0 - EXT2 is that a normal speed?

    Read the article

  • NAS Performance issues

    - by Markus
    I bought a NAS from Conceptronic CH3MNAS and built in two Western Digital 1,5TB Green Drives. I only get a write speed of 6mb/s in LAN The configuration of the drives is as follows: - Raid 0 - EXT2 Is that a normal speed?

    Read the article

  • Troubleshooting Network Speeds -- The Age Old Inquiry

    - by John K
    I'm looking for help with what I'm sure is an age old question. I've found myself in a situation of yearning to understand network throughput more clearly, but I can't seem to find information that makes it "click" We have a few servers distributed geographically, running various versions of Windows. Assuming we always use one host (a desktop) as the source, when copying data from that host to other servers across the country, we see a high variance in speed. In some cases, we can copy data at 12MB/s consistently, in others, we're seeing 0.8 MB/s. It should be noted, after testing 8 destinations, we always seem to be at either 0.6-0.8MB/s or 11-12 MB/s. In the building we're primarily concerned with, we have an OC-3 connection to our ISP. I know there are a lot of variables at play, but I guess I was hoping the experts here could help answer a few basic questions to help bolster my understanding. 1.) For older machines, running Windows XP, server 2003, etc, with a 100Mbps Ethernet card and 72 ms typical latency, does 0.8 MB/s sound at all reasonable? Or do you think that slow enough to indicate a problem? 2.) The classic "mathematical fastest speed" of "throughput = TCP window / latency," is, in our case, calculated to 0.8 MB/s (64Kb / 72 ms). My understanding is that is an upper bounds; that you would never expect to reach (due to overhead) let alone surpass that speed. In some cases though, we're seeing speeds of 12.3 MB/s. There are Steelhead accelerators scattered around the network, could those account for such a higher transfer rate? 3.) It's been suggested that the use SMB vs. SMB2 could explain the differences in speed. Indeed, as expected, packet captures show both being used depending on the OS versions in play, as we would expect. I understand what determines SMB2 being used or not, but I'm curious to know what kind of performance gain you can expect with SMB2. My problem simply seems to be a lack of experience, and more importantly, perspective, in terms of what are and are not reasonable network speeds. Could anyone help impart come context/perspective?

    Read the article

  • computing matting Laplacian matrix of an Image

    - by ajith
    hi everyone, i need to compute Laplacian Matrix-L for an image(nXn) in opencv...computing goes as follows.......... dij - 1/|wk|{[1+1/(e/|wk|+s2)][(Ii-µk)*(Ij -µk)]}.... for all(i,j)?wk,summing over k yields (i,j)th element of L. where Here dij is the Kronecker delta,µk and s2k are the mean & variance of intensities in the window wk around k,and |wk| is the number of pixels in this window.wk is 3X3 window... here am not clear about 2 things... 1.what ll be the size of L?nXn or (nXn)X(nXn)?? 2.how to select Ii and Ij separately in 2D image?

    Read the article

  • HIGH CPU usage by PHP on a VPS Magento Server

    - by Anil
    My server running magento is 4gb ram and 4 core cpu. But still i am struggling with the high CPU usage. I only have 10 visitors at any given point of time. I am not sure if the PHP has to take this high % CPU usage. Attached is the TOP result. top - 09:18:32 up 2 days, 15:44, 1 user, load average: 1.16, 2.02, 1.99 Tasks: 179 total, 2 running, 177 sleeping, 0 stopped, 0 zombie Cpu(s): 46.7%us, 3.9%sy, 0.1%ni, 46.9%id, 1.0%wa, 0.0%hi, 0.0%si, 1.4%st Mem: 3919972k total, 3164968k used, 755004k free, 530820k buffers Swap: 1048568k total, 379352k used, 669216k free, 1536388k cached PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND 15897 vpsadmin 20 0 431m 168m 54m R 91.7 4.4 2:16.16 php-cgi 12308 vpsadmin 20 0 404m 163m 73m S 29.3 4.3 15:15.90 php-cgi 3644 mysql 20 0 1528m 80m 4944 S 9.8 2.1 1899:58 mysqld 4969 apache 20 0 471m 6228 2824 S 2.0 0.2 0:18.53 httpd 16148 root 20 0 15024 1220 864 R 2.0 0.0 0:00.01 top 1 root 20 0 19364 1064 844 S 0.0 0.0 0:02.50 init

    Read the article

  • High Memory Utilization on weblogic

    - by Anup
    My Weblogic App Server shows high Memory Utization. The application seems to perform good without any memeory issues. Now that my traffix is going to increase i am worried about the memory and have a feeling things could go bad and need to take action now and i am confused as to should i increase The JVM memory on the weblogic instances which means adding more physical memory or should i increase the number of managed instances in the cluster. Would like to understand what does having high memory utilization mean and the advantage and disadvantages of adding JVM memory and adding managed instances. Thanks

    Read the article

  • High Memory Utilization on weblogic

    - by Anup
    My Weblogic App Server shows high Memory Utization. The application seems to perform good without any memeory issues. Now that my traffix is going to increase i am worried about the memory and have a feeling things could go bad and need to take action now and i am confused as to should i increase The JVM memory on the weblogic instances which means adding more physical memory or should i increase the number of managed instances in the cluster. Would like to understand what does having high memory utilization mean and the advantage and disadvantages of adding JVM memory and adding managed instances. Thanks

    Read the article

  • Ultra high pitched noice coming from computer

    - by user11177
    It happened twice today, first a few minutes after turning on the computer (stopped by itself after a few minutes), then several hours later after I had turned my computer off, it started emitting a faint, ultra high pitched noise. The noise is not very loud, and almost to high pitch to be audible, but definitely noticeable for my ears. I sleep in the same room as my computer, so at first I was confused when I had just turned it off and started hearing the noise, so I went out of the room to check if the noise was in my head, but no it was definitely coming from the comp. It stopped when I turned it back on. What can be the possible causes for this phenomenon? How can I fix it?

    Read the article

< Previous Page | 34 35 36 37 38 39 40 41 42 43 44 45  | Next Page >