performance

Hyper-V monitor virtual machine disk activity

How can I get the number of bytes read from/written into the physical disk of the host system by Hyper-V virtual machines? ...

Why doesn't this CompiledQuery give a performance improvement?

I am trying to speed up an often used query. Using a CompiledQuery seemed to be the answer. But when I tried the compiled version, there was no difference in performance between the compiled and non-compiled versions. Can someone please tell me why using Queries.FindTradeByTradeTagCompiled is not faster than using Queries.FindTradeByTr...

How to measure peak memory size etc. during a given interval in Windows

With PROCESS_MEMORY_COUNTERS_EX, I can find the peak pagefile (VM) size since the beginning of a process. Can I somehow get the peak pagefile size starting from some other point in time? ...

Do console apps run faster than GUI apps?

I am relatively new to world of programming. I have a few performance questions: Do console apps run faster than apps with a graphical user interface? Are languages like C and Pascal faster than object oriented languages like C++ and Delphi? I know language speed depends more on compiler than on language itself, but do compilers for pr...

Image 8-connectivity without excessive branching?

I'm writing a low level image processing algorithm which needs to do alot of 8-connectivity checks for pixels. For every pixel I often need to check the pixels above it, below it and on its sides and diagonals. On the edges of the image there are special cases where there are only 5 or 3 neighbors instead of 8 neighbors for a pixels. Th...

Which one can have better performance - LINQ to EF or NHibernate?

I want to start working on a big project. I research about performance issues about LINQ to EF and NHibernate. I want to use one of them as ORM in my project. now my question is that which one of these two ORM can get me better performance in my project? I will use SQL Server 2008 as database and C# as programming language. ...

Open source / commercial alternative for jiffy.js?

Hi, we'd like to measure "client side web site performance". i.e. we would like to have answers to the following questions: how long did it takt to load and render a webpage (including alle graphics scripts etc.) this bundled with additional informations like user-agent, operating system etc. a graphical tool to analyze the data would...

can adding jQuery listeners slow down browser performance?

I have application that brings response via Ajax and creates 5-20 new jQuery click listeners on each refresh. Both IE and mozilla browsers seem to be slowing down with usage. Can this slow down browser performance significantly. Can listeners be "released"? ...

Flash player freezes in fullscreen mode

A lot of users on one of our online apps complain about the app freezing in the fullscreen mode. I googled and came across many others complaining about this problem for other flash apps. Is it such a common problem, or are there known causes for it? ...

Speeding up a soap powered website

Hi all, We're currently looking into doing some performance tweaking on a website which relies heavily on a Soap webservice. But ... our servers are located in Belgium and the webservice we connect to is locate in San Francisco so it's a long distance connection to say the least. Our website is PHP powered, using PHP's built in SoapCli...

How can I intercept a Tomcat request at socket level?

Hi, I'm doing a performance study for a web application framework running on Apache Tomcat 6. I'm trying to measure the time overhead of handling HTTP requests. What I would like to do is: / // just before first request byte is read long t1 = System.nanoTime(); // request is processed... // just after final byte is written to resp...

ListViewColumnSorter cause of performance issues with adding listView Items in C#?

For some time I've been having difficulties with one of my ListView's being populated very slowly (3000 entries in 15 secs or so (with 5 columns). It was driving me mad since sql query returned values in less then second. I tracked it down to ListViewColumnSorter being the slowdown. When i commented out: private ListViewColumnSorter lv...

SQL indexing on varchar

I have a table whose columns are varchar(50) and a float. I need to (very quickly) look get the float associated with a given string. Even with indexing, this is rather slow. I know, however, that each string is associated with an integer, which I know at the time of lookup, so that each string maps to a unique integer, but each integer...

Advantages of Sybase's AseClient for ADO.Net 2 over the ODBC driver

We have an ETL process that reads data from a Sybase DB via the ODBC "Adaptive Server Enterprise" driver v12.05 I'm wondering if there any any performance advantages specifically to migrating to the .Net 2 Sybase.AdoNet2.AseClient.dll ? ...

Is there any other way to store data in web application

We use ViewState to store data that is being edited by users. However, ViewState just got too large so we really want something that is faster. We considered session, but it has to be manually collected when users travel among pages. Does anybody has suggestions? update: Actually I am using Asp.net. They reason we do not want to use s...

fastest (low latency) method for Inter Process Communication between Java and C/C++

Hello, I have a Java app, connecting through TCP socket to a "server" developed in C/C++. both app & server are running on the same machine, a Solaris box (but we're considering migrating to Linux eventually). type of data exchanged is simple messages (login, login ACK, then client asks for something, server replies). each message is a...

Efficient way to update all rows in a table

Hi, I have a table with a lot of records (could be more than 500 000 or 1 000 000). I added a new column in this table and I need to fill a value for every row in the column, using the corresponding row value of another column in this table. I tried to use separate transactions for selecting every next chunk of 100 records and update t...

What this phrase "Try to make you architecture more horizontal rather than vertical" means?

Hello, I've just listened to http://www.zend.com/webinar/PHP/70170000000bAuS-webinar-php-performance-principles-and-tools-20100218.flv (Zend webinar about PHP performance). I can't understand what this phrase means "Try to make you architecture more horizontal rather than vertical" (see screenshot) Thank you. ...

Optimizing code using PIL

Firstly sorry for the long piece of code pasted below. This is my first time actually having to worry about performance of an application so I haven't really ever worried about performance. This piece of code pretty much searches for an image inside another image, it takes 30 seconds to run on my computer, converting the images to greysc...

Parallel version of loop not faster than serial version

I'm writing a program in C++ to perform a simulation of particular system. For each timestep, the biggest part of the execution is taking up by a single loop. Fortunately this is embarassingly parallel, so I decided to use Boost Threads to parallelize it (I'm running on a 2 core machine). I would expect at speedup close to 2 times the...