Computer Chess Club Archives


Search

Terms

Messages

Subject: Re: Is Xeon 5000 (Dempsey) with FB-DIMMs faster then Opteron 280 ?

Author: Aaron Gordon

Date: 17:40:57 11/10/05

Go up one level in this thread


On November 10, 2005 at 00:28:24, Robert Hyatt wrote:

>>hypertransport isn't the bottleneck at all as that delivers hands down 14.4GB/s
>>a channel.
>
>There is more to this than "bandwidth".  There is "latency" and there are
>"conflicts"


I don't know too much about the technical workings of new bus system AMD uses on
the Athlon 64/Opteron type systems. Hopefully you could clear something up for
me, I would appreciate it.

I tested my Athlon 64 3700+ (2.2GHz, single cpu, single core) running at
standard 200MHz bus with my HT multiplier at the normal 5 (5x200=1000MHz HT). I
ran Crafty 19.15 64bit and got 2321134 nodes/second. I then set the HT
multiplier down to 1x, resulting in an HT bus of 200MHz (5 times slower). I
retested Crafty and got the exact same NPS as before.

If a drastic reduction of the HT bus speed results in zero nps loss, my initial
guess is that it would have almost no effect on Crafty whether the dual core (or
cpu) setup has one or two HT links. If this is not the case and Crafty does run
slower, why exactly does this happen?



This page took 0 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.