http://ayende.comAyende @ RahienCopyright (C) Ayende Rahien 2004 - 2021 (c) 202660Ok, there is another, slighly improved version that avoid static class and ThreadStatic. With this one I reach 450M objects. BTW I am using my desktop PC with a i7CPU (4x2 core) with many apps opened (5 instances of vs.net, services, etc.). Running on a real server architecture with Xeon CPUs _should_ give a *huge* boost due to larger L2 cache (CLR trys to put Gen0 in L2). Cheers // 22threads, release: Created 450.691.605 in 00:00:00.9997830 // Created 452.639.194 in 00:00:01.0001203 // Created 452.955.475 in 00:00:00.9995694 static void Main(string[] args) { long counter; TimeSpan elapsed; var perf = new Version2(); perf.DoLoop2(out counter, out elapsed); // shortcut for jitting GC.Collect(); GC.Collect(); GC.Collect(); GC.WaitForFullGCComplete(-1); Thread.Sleep(1000); perf.DoLoop2(out counter, out elapsed); // real count Console.WriteLine("Created {0:#,###} in {1}", counter, elapsed); Console.ReadKey(); } public class Version2 { volatile bool isGoing = true; long sharedCounter = 0; int maxThreads = 22; public void DoLoop2(out long counter, out TimeSpan elapsed) { ManualResetEventSlim evWait = new ManualResetEventSlim(false); ManualResetEventSlim evStart = new ManualResetEventSlim(false); ThreadStart ts = new ThreadStart( () => { int threadCounter = 0; evStart.Wait(); while (isGoing) { new MyClass(); threadCounter++; } Interlocked.Add(ref sharedCounter, threadCounter); }); var pool = new List <thread(); for (int x = 0; x < maxThreads; x++) pool.Add(new Thread(ts)); foreach (var p in pool) p.Start(); var sp = Stopwatch.StartNew(); evStart.Set(); evWait.Wait(1000); isGoing = false; sp.Stop(); foreach (var p in pool) p.Join(); counter = sharedCounter; elapsed = sp.Elapsed; } } >http://ayende.com/4811/performance-numbers-in-the-pub#comment37http://ayende.com/4811/performance-numbers-in-the-pub#comment37Wed, 04 May 2011 09:14:51 GMTRaff is the king! :-) .m http://ayende.com/4811/performance-numbers-in-the-pub#comment36http://ayende.com/4811/performance-numbers-in-the-pub#comment36Fri, 29 Apr 2011 11:41:05 GMTOk, I'll try to challenge :) - original code: 16M - code below: 400M Both tested in release mode. MyClass is the original one. Here is my code ... hopefully not forgetting anything :) [ThreadStaticAttribute] static int threadCounter = 0; // 22threads, release: Created 389.068.025 in 00:00:00.9997334 // Created 408.390.521 in 00:00:00.9996904 // Created 417.618.531 in 00:00:01.0003762 static void Main(string[] args) { int counter; TimeSpan elapsed; DoLoop(out counter, out elapsed); // shortcut for jitting GC.Collect(); GC.Collect(); GC.Collect(); GC.WaitForFullGCComplete(-1); Thread.Sleep(1000); DoLoop(out counter, out elapsed); // real count Console.WriteLine("Created {0:#,###} in {1}", counter, elapsed); Console.ReadKey(); } static void DoLoop(out int counter, out TimeSpan elapsed) { int maxThreads = 22; int sharedCounter = 0; bool isGoing = true; ManualResetEvent evWait = new ManualResetEvent(false); ManualResetEvent evStart = new ManualResetEvent(false); Action action = () => { evStart.WaitOne(); while (isGoing) { new MyClass(); threadCounter++; } Interlocked.Add(ref sharedCounter, threadCounter); }; ThreadStart ts = new ThreadStart(action); List <thread pool = new List <thread(); for (int x = 0; x < maxThreads; x++) pool.Add(new Thread(ts)); foreach (var p in pool) p.Start(); var sp = Stopwatch.StartNew(); evStart.Set(); evWait.WaitOne(1000); isGoing = false; sp.Stop(); foreach (var p in pool) p.Join(); counter = sharedCounter; elapsed = sp.Elapsed; } >http://ayende.com/4811/performance-numbers-in-the-pub#comment35http://ayende.com/4811/performance-numbers-in-the-pub#comment35Fri, 29 Apr 2011 11:20:59 GMTMy average result was 14millions http://ayende.com/4811/performance-numbers-in-the-pub#comment34http://ayende.com/4811/performance-numbers-in-the-pub#comment34Sat, 23 Apr 2011 09:49:29 GMTI thought I had a good computer. 3.579.220 objects in one sec. Asus Core i7 with 4 gig of Ram http://ayende.com/4811/performance-numbers-in-the-pub#comment33http://ayende.com/4811/performance-numbers-in-the-pub#comment33Sun, 17 Apr 2011 19:48:58 GMTCreated 11711225 in 00:00:01:00000090 Press any key to continue . . . http://ayende.com/4811/performance-numbers-in-the-pub#comment32http://ayende.com/4811/performance-numbers-in-the-pub#comment32Fri, 15 Apr 2011 16:50:16 GMT@Patrick Correct you are, sir! http://ayende.com/4811/performance-numbers-in-the-pub#comment31http://ayende.com/4811/performance-numbers-in-the-pub#comment31Fri, 15 Apr 2011 11:38:28 GMT@Zach "Datetime is itself an object reference type which may contain other value and reference types." No, DateTime is a struct, a value type. And it has only one instance field, an ulong. http://ayende.com/4811/performance-numbers-in-the-pub#comment30http://ayende.com/4811/performance-numbers-in-the-pub#comment30Fri, 15 Apr 2011 09:29:43 GMTI figured "sp.ElapsedMilliseconds" had quite high overhead, so I set a 'granularity', only check the elapsed time every 1,000 iterations, then subtract 1,000 from the final count to say 'at least' that many were created... My count jumped from 5.2 million, to over 42 million. http://ayende.com/4811/performance-numbers-in-the-pub#comment29http://ayende.com/4811/performance-numbers-in-the-pub#comment29Thu, 14 Apr 2011 21:13:47 GMTHere is the real test: class Program { static void Main(string[] args) { var sp = Stopwatch.StartNew(); int i = 0; while (sp.ElapsedMilliseconds < 1000) { new MyClass(); i++; } sp.Stop(); Console.WriteLine("Created {0} in {1}", i, sp.Elapsed); Console.ReadLine(); } public class MyClass { public MyClass() { new MyClass(); } } } http://ayende.com/4811/performance-numbers-in-the-pub#comment28http://ayende.com/4811/performance-numbers-in-the-pub#comment28Thu, 14 Apr 2011 19:00:25 GMT@stefan: agreed. I was simply pointing out that for the pure academic version of the question "How many CLR objects can you create in one second?" we should just use new object(); rather than MyClass at all. http://ayende.com/4811/performance-numbers-in-the-pub#comment27http://ayende.com/4811/performance-numbers-in-the-pub#comment27Thu, 14 Apr 2011 18:59:03 GMT@zach: .net zeroes out every field on construction, so more fields = more time. additional reference fields also mean more tracking work for the GC to do, so if you want to measure only construction time (not GC time), you should avoid them. or somehow measure the main thread's time only. but all those tests just show that it would have to be orders of magnitude slower to justify wasting a single thought on it. except if charles is your customer, that is ;-) http://ayende.com/4811/performance-numbers-in-the-pub#comment26http://ayende.com/4811/performance-numbers-in-the-pub#comment26Thu, 14 Apr 2011 18:53:47 GMTKevdog, Thats nothing... the best I got with my work computer was 479816. Yes, that's approximately half a million. I tried everthing to get a higher number but just can't. Needless to say that my computer is a piece of s#$t. Probably second only to the guy behind me with a P4. Luckily this is my second to last day at this job. http://ayende.com/4811/performance-numbers-in-the-pub#comment25http://ayende.com/4811/performance-numbers-in-the-pub#comment25Thu, 14 Apr 2011 18:18:21 GMT@stefan Oh and I forgot to add, this still suffers from the compound object creation problem associated with the MyClass object containing an integral value type and two reference types, one which is a compound type itself. Thus we are actually counting the number of MyClass objects that can be created per second not the number of CLR objects that can be created per second. Changing the code to this: int reps = 1000000000; sp.Start(); for (int j = 0; j < reps; ++j) { new object(); } sp.Stop(); Console.WriteLine("Created {0} in 1 sec", reps / sp.Elapsed.TotalSeconds); The count moves up by about 16% to 240M obj/s for a single thread and almost a Billion obj/s (Created 924214000 in 1 sec) for 8 threads on a 2.4GHz Xeon E5620. http://ayende.com/4811/performance-numbers-in-the-pub#comment24http://ayende.com/4811/performance-numbers-in-the-pub#comment24Thu, 14 Apr 2011 17:58:26 GMTRyan, This is probably because the call was optimized to be a non recursive call http://ayende.com/4811/performance-numbers-in-the-pub#comment23http://ayende.com/4811/performance-numbers-in-the-pub#comment23Thu, 14 Apr 2011 17:57:42 GMTInteressing. When I change NeverReturn into static void NeverReturn1() { NeverReturn(); } static void NeverReturn() { NeverReturn1(); } The program crashes immediately as expected. Why doesn't the simple version crash as well? I looked up the IL but I see no difference ... // Ryan http://ayende.com/4811/performance-numbers-in-the-pub#comment22http://ayende.com/4811/performance-numbers-in-the-pub#comment22Thu, 14 Apr 2011 17:46:51 GMT@remi from int.MinValue to int.MaxValue 508ms var sp = new Stopwatch(); sp.Start(); for(var i = int.MinValue; i < int.MaxValue; i++); sp.Stop(); Console.WriteLine("{0} ms", sp.ElapsedMilliseconds); Console.ReadLine(); Surprisingly StackOverflowException will take ages, I didn't want to wait for it ... void NeverReturn() { NeverReturn(); } var sp = new Stopwatch(); sp.Start(); try { NeverReturn(); } catch(StackOverflowException) { Console.WriteLine("{0} ms", sp.ElapsedMilliseconds); Console.ReadLine(); } // Ryan http://ayende.com/4811/performance-numbers-in-the-pub#comment21http://ayende.com/4811/performance-numbers-in-the-pub#comment21Thu, 14 Apr 2011 17:32:58 GMT@Stefan - You are correct that the objects are created either way. I should have gone to the MSIL earlier. You can see below that it IS making the newobj call. I haven't dug enough beyond this to confirm if it is GC0 vs GC1 or the stopwatch, or the conversions, or some of the other overhead involved that is causing the slow down. Using your code, I can confirm that I too get much higher numbers (now ~207M obj/s vs 15M obj/s) using a single thread (and around 475-500M obj/s using 8 threads). Created 206799368.856598 in 1 sec Here is the (relevant) C# code: ... while (sp.ElapsedMilliseconds < lengthOfRunInMS) { new MyClass(); numObjs++; } sp.Stop(); ..... public class MyClass { public string a; public int B; public DateTime C; } And the resulting IL: .entrypoint // Code size 146 (0x92) .maxstack 4 .locals init (int64 V_0, int64 V_1, int32 V_2, int32 V_3, class [System]System.Diagnostics.Stopwatch V_4) // Cut a bunch of code here // Create, store, and start stop watch IL_000b: stloc.3 IL_000c: call class [System]System.Diagnostics.Stopwatch [System]System.Diagnostics.Stopwatch::StartNew() IL_0011: stloc.s V_4 // Branch to while loop conditional IL_0013: br.s IL_001f // new MyClass IL_0015: newobj instance void CLRObjectCreationTest.MyClass::.ctor() IL_001a: pop // newObj++ (Load, increment by 1, and store ) IL_001b: ldloc.3 IL_001c: ldc.i4.1 IL_001d: add IL_001e: stloc.3 // sp.ElapsedTime IL_001f: ldloc.s V_4 IL_0021: callvirt instance int64 [System]System.Diagnostics.Stopwatch::get_ElapsedMilliseconds() // Load while loop guard (1000) IL_0026: ldc.i4 0x3e8 // Convert the loop guard to an Int64 IL_002b: conv.i8 // Loop back through our while loop if the elapsed time is less than the loop guard IL_002c: blt.s IL_0015 http://ayende.com/4811/performance-numbers-in-the-pub#comment20http://ayende.com/4811/performance-numbers-in-the-pub#comment20Thu, 14 Apr 2011 17:26:13 GMT@Stefan You should at least bump reps up to 210.000.000 because now your program is lying to you :P // Ryan http://ayende.com/4811/performance-numbers-in-the-pub#comment19http://ayende.com/4811/performance-numbers-in-the-pub#comment19Thu, 14 Apr 2011 17:18:04 GMTWhoa, performance myths on top of performance myths! You're only measuring the stopwatch performance of here, object creation is way faster. Which leads people to all kinds of wrong conclusions, of course (java is faster, new is optimized away...) int reps = 100000000; sp.Start(); for (int j = 0; j < reps; ++j) new MyClass(); sp.Stop(); Console.WriteLine("Created {0} in 1 sec", reps/sp.Elapsed.TotalSeconds); Created 14631788 in 00:00:01 becomes Created 202107618,669004 in 1 sec @zach: the performance impact you get is from GC. without storing the references, its all done in generation 0 which is fast. but the objects are created either way. http://ayende.com/4811/performance-numbers-in-the-pub#comment18http://ayende.com/4811/performance-numbers-in-the-pub#comment18Thu, 14 Apr 2011 16:05:49 GMTMaybe I made a mistake but by pub yo mean draft beer, old painting on the wall.... It's really fun to read a useless challenge becoming a serious discussion (with code, blog post, technical spec and all). You guys must be the best booze pal ever. In how many milliseconds do you think you can go from int.MinValue to int.MaxValue ? or get a StackoverfloxException ? http://ayende.com/4811/performance-numbers-in-the-pub#comment17http://ayende.com/4811/performance-numbers-in-the-pub#comment17Thu, 14 Apr 2011 15:06:26 GMTI made some changes to source code to use multiple cores (using TPL) as well as some other optimizations. You can read more if it sounds interesting at [blog.evereq.com/.../net-performance-and-your-ha...](http://blog.evereq.com/blog/index.php/2011/04/net-performance-and-your-hardware/) :) http://ayende.com/4811/performance-numbers-in-the-pub#comment16http://ayende.com/4811/performance-numbers-in-the-pub#comment16Thu, 14 Apr 2011 14:54:17 GMTFirst run was only 25,009,970, but after that I averaged about 25.56-25.57 million per run. Not too shabby. Hardware: i7-2600k OC to 4.6ghz, 16gb ddr3-1600, cheapie SSD, win7x64. http://ayende.com/4811/performance-numbers-in-the-pub#comment15http://ayende.com/4811/performance-numbers-in-the-pub#comment15Thu, 14 Apr 2011 13:31:58 GMTHere is the code I used in case anyone cares: using System; using System.Diagnostics; namespace CLRObjectCreationTest { internal class Program { private static void Main(string[] args) { Int64 totalObjectCount = 0; Int64 totalElapsedTimeInMS = 0; const int numberOfRuns = 60; const int lengthOfRunInMS = 1000; for (int run = 0; run < numberOfRuns; run++) { MyClass[] myClasses = new MyClass[50000000]; int numObjs = 0; Stopwatch sp = Stopwatch.StartNew(); while (sp.ElapsedMilliseconds < lengthOfRunInMS) { myClasses[numObjs] = new MyClass(); numObjs++; } sp.Stop(); Console.WriteLine("Number of objects created {0} in {1} seconds.", numObjs, (sp.ElapsedMilliseconds/lengthOfRunInMS)); totalObjectCount += numObjs; totalElapsedTimeInMS += sp.ElapsedMilliseconds; } Console.WriteLine("Average number of objects created {0} in {1} seconds.", (totalObjectCount/numberOfRuns), totalElapsedTimeInMS/(numberOfRuns*lengthOfRunInMS)); } } public class MyClass { public string a; public int B; // public DateTime C; } } http://ayende.com/4811/performance-numbers-in-the-pub#comment14http://ayende.com/4811/performance-numbers-in-the-pub#comment14Thu, 14 Apr 2011 12:50:25 GMTThere are a few things wrong with this test. I know this was a "back of the napkin in the pub" kind of converstation and the main point is "you can create a crapload of CLR objects per second". Since some people however, seem to be running with this, I figured I'd point a few of my observations out. First, some background on how I ran these tests so that others may compare more easily. - Each test run was 1000 milliseconds. - I ran each test run 60 times and averaged the results. - I built the project in the Release x86 configuration - I'm running Windows 7 64-bit SP1 and .NET v4.0.30319 - I used a console application and targeted the .NET Framework 4 Client Profile - I ran my tests detached built from the debugger (Ctrl-F5) which increased the number of objects created per second by 170% - My machine has 12GB of DDR3 and an Intel Xeon E5620 @ 2.4GHz Observations: - The CLR is optimizing out the creation of each additional object via the call to new in the loop. Your code is actually only testing how many times your can increment a counter in one second - minus the time to create a single MyClass object - Actually storing the object references in an array that doesn't lose scope lowers the "score" by approximately 50% - Average Number of MyClass objects (int/string/Datetime) created per second that aren't stored: 14 053 546 - Average Number of MyClass objects (int/string/Datetime) created per second stored in an array: 6 943 109 - Moving the new MyClass call outside of the while loop so that all the loop does is increment the counter only increases "score" by 6% - Only executing the while loop and incrementer and not creating a MyClass object at all only increases the "score" by 7% - Your "MyClass" contains an integral value type (int) and two reference types (string and Datetime). Datetime is itself an object reference type which may contain other value and reference types. - Changing the definition of MyClass substantially changes the numbers (number of objs created as percent of original) - string/int/Datetime 100% - string/int 113% - string 120% - int 122% - The first run of each series was slower than the average by about 25% but was not the slowest run in the series http://ayende.com/4811/performance-numbers-in-the-pub#comment13http://ayende.com/4811/performance-numbers-in-the-pub#comment13Thu, 14 Apr 2011 12:44:46 GMTYet more evidence that my employer buys crap computers for programmers: 4975448 http://ayende.com/4811/performance-numbers-in-the-pub#comment12http://ayende.com/4811/performance-numbers-in-the-pub#comment12Thu, 14 Apr 2011 12:35:51 GMTCreated 11 526 398 in 00:00:01.0000041 Press any key to continue . . . http://ayende.com/4811/performance-numbers-in-the-pub#comment11http://ayende.com/4811/performance-numbers-in-the-pub#comment11Thu, 14 Apr 2011 12:29:07 GMTJoao, There is a lot that can cause that change. http://ayende.com/4811/performance-numbers-in-the-pub#comment10http://ayende.com/4811/performance-numbers-in-the-pub#comment10Thu, 14 Apr 2011 12:06:44 GMTOn my notebook. using .NET: Created 732239 in 00:00:01.0000016. using Java: Created 26248216 in 1000ms. I am blown away by the difference. http://ayende.com/4811/performance-numbers-in-the-pub#comment9http://ayende.com/4811/performance-numbers-in-the-pub#comment9Thu, 14 Apr 2011 11:36:46 GMTAre you sure that the object is even created and that the compiler does not optimize the loop? Check it with IL Dasm ;-) http://ayende.com/4811/performance-numbers-in-the-pub#comment8http://ayende.com/4811/performance-numbers-in-the-pub#comment8Thu, 14 Apr 2011 11:28:05 GMT