On Sun, 6 Oct 2002, Randy Clarksean wrote:

>
> I just put together a new AMD XP 2100+ system and installed RedHat 7.2  The intent of this machine is heavy computational work (1.5 GB RAM, 80 GB HD, ABIT Motherboard with PC2100 RAM).  I have an older Win2000 Machine, dual PIII 700 MHz 1 GB RAM - TYAN Motherboard  that I have been using for computational work.
>
> I have data from an analysis run on the PIII system (1 CPU) and I just ran that same analysis on the new AMD21+ system.  The speed improvement was NOT what I hoped for.
>
> PIII 700 MHz              96,360 seconds
> AMD XP 2100+          65,040 seconds
>
> I do realize that there are operating system issues, etc. ... but with all of that I had anticipated a larger reduction in computational time.  The code I am running is a commercial code that is developed to run on both operating systems, so I am fairly sure they work to get the best CPU time on both platforms.  I was hoping for something on the order of 1/2 the CPU time - on large computational runs like this every little reduction in time helps.
>
> Not being a "kernel" expert by any means ... would it make any sense to recompile the kernel on my new platform, rather than relying on the kernel as loaded from the RH7.2 distribution CDs?  Any suggestions would be greatly appreciated!
>
I have been doing some benchmarking of Athlon vs Pentium systems lately.

1. It is probably not something that a kernel recompile will help
   significantly.

2. Recompiling the App with gcc-3.? with Athlon optimization turned
   on would probably provide very significant improvement.
   I have discovered that CPU optimization in the application makes
   a very large difference for the app I have been checking.

3. If it is an application that is highly parallelized you _might_ try
   playing with the latest 2.5 series kernel with the O(1) scheduler.
   Note that this could be rather more "educational" than you are
   ready for.

-- 
Daniel Taylor
dante at plethora.net
And Carthage must be destroyed!