Computer Chess Club Archives


Search

Terms

Messages

Subject: Re: Faster than dual Xeon 2.8GHz?

Author: Tom Kerrigan

Date: 04:19:50 04/21/03

Go up one level in this thread


On April 21, 2003 at 05:05:08, Aaron Gordon wrote:

>The same way a Celeron 1GHz, P3-933MHz or 900MHz Athlon is faster than a Pentium
>4 1.5GHz. MHz isn't everything. Pentium 4's were made with only 1 thing in mind,
>marketing. Make a chip with high MHz so people will think it's faster. To get
>those high MHz numbers they had to gimp the CPU, which is why the Pentium 4's
>are ridiculously slow MHz for MHz.
>
>In some applications it has the IPC (instructions per cycle) of a 486. I don't
>know about you, but I upgraded from a 486 a long time ago.. :)

What part of the P4 is gimped?

According to SPECint,

http://www.aceshardware.com/SPECmine/index.jsp?b=0&s=2&v=2&if=0&r1f=2&r2f=0&m1f=0&m2f=0&o=0&o=1

AXP only has 15% more IPC than a P4. Also notice that the AXP has dramatically
lower IPC than MIPSs, PA-RISCs, POWERs, and Alphas. Surely you will argue that
AMD sacrificed IPC for clock speed for a net gain in performance. Perfectly
legitimate argument, and the same argument one could make for the P4.

BTW, while I definitely share your enthusiasm for Opteron, I wouldn't get
people's hopes up with talk of blazing speed. Chess programs run mainly in
cache, so the on-die memory controller won't help much. Chess programs don't
require a ton of inter-processor bandwidth, so HT won't help much. Chess
programs may benefit significantly from x86-64 in the future but high-quality
x86-64 compilers won't be here for a while. What's left? Some improvements to
the core, which may or may not be offset by the higher branch mispredict
penalties, and I doubt they'd make up for the 15+% difference in clock speed
between the Opteron and the AXP. I expect AMD to ramp up Opteron (and A64) clock
speeds quickly, so they will be quite good for computer chess, but this week
won't offer anything mind-bending to computer chess enthusiasts.

-Tom



This page took 0.02 seconds to execute

Last modified: Thu, 15 Apr 21 08:11:13 -0700

Current Computer Chess Club Forums at Talkchess. This site by Sean Mintz.