Performance Opteron 2435 (2Cpu 6core) - can anybody help?

Discussion created by dbtp123 on Feb 25, 2010
Latest reply on Feb 27, 2010 by avk
Opteron 2435 w Windows 2008 Server SP2 64 bit w disappointing performance


Hi all,

Performance on our new 2 CPU 6core 2.66Ghz Opterons 2435 is a bit disappointing and I have no idea where to look or what I can do about it.  I hope somebody can put us in the right direction.

Comparison is done with a 2 CPU Intel Xeon X5450 3.00Ghz (4core, also Windows 2008 Server 64 bit) - and also with my Windows XP Desktop.

The application (C#) uses multiple threads to read/process/write multiple files and runs about 37 minutes on Opteron and 23 minutes on Intel. CPU usage on Opteron is about 15% average, on Intel (exact same program and data ) about 30%. For some reason it just doesn't use all that cpu power. Somewhere seems to be a bottleneck (it is not IO).

We also created a little test application (see attached code) that only does some integer processing and this shows the same (even worse) behavior on Opteron being slower. Java or .Net doesn't seem to make a difference with this one.

We are stuck at the moment and would really appreciate if anybody can give some hints.

Many thanks,



int num; int i; int factor; bool isprime; DateTime startTime = DateTime.Now; textBox2.Text = "Working..."; textBox2.Refresh(); for (num = 2; num < Convert.ToInt64(textBox1.Text); num++) { isprime = true; factor = 0; // see if num is evenly divisible for (i = 2; i <= num / 2; i++) { if ((num % i) == 0) { // num is evenly divisible -- not prime isprime = false; factor = i; } } } DateTime stopTime = DateTime.Now; TimeSpan elapsedTime = stopTime - startTime; textBox2.Text = elapsedTime.ToString();