Author: Gabor Szots
Date: 11:52:53 11/01/05
Go up one level in this thread
On November 01, 2005 at 14:45:17, Aaron Gordon wrote: >On November 01, 2005 at 13:21:05, Gabor Szots wrote: > >>On November 01, 2005 at 12:41:25, Aaron Gordon wrote: >> >>>>Thanks, Günther. A disappointment as P4 is concerned... >>>> >>>>Regards, >>>>Gábor >>> >>>As far as HT goes, please take Hyatts advice there. I don't know the exact >>>numbers, but here is a decent example. Lets say you've got a dual CPU system >>>where 1 cpu takes 60 seconds to hit 16 ply. As soon as you switch to 2 >>>threads/cpus, you get a 20% performance decrease. So, lets figure two cpus that >>>can do 16 ply in 60 seconds a piece, minus 20%. That puts us at ~36 seconds, a >>>nice improvement over 1 cpu. >>> >>>Now, with HT, it isn't a real second CPU. So, lets say we take that same >>>performance decrease and see what it does with HT enabled. >>>60 seconds per cpu again, 1 cpu. HT will probably benefit you about 10%, but, >>>going into SMP mode again drops you 20%. So, you actually lose performance. Now >>>your 60 second time turns into about 64.8 seconds (if I did my math properly, >>>heh). >>> >>>Here are some benchmarks I ran to compare a few systems. This is with Crafty >>>19.15 compiled by Bryan Hofmann (http://cito.atspace.com/) run with the "bench" >>>command and 48mb hash. I would have enabled HT for the P4 test, however, my P4 >>>does not have HT. >>> >>>3054kn/s - Athlon 64 2.85GHz (San Diego) 64 bit >>>2149kn/s - Athlon 64 2.85GHz (San Diego) 32 bit >>>1934kn/s - Athlon 64 1.80GHz (San Diego) 64 bit >>>1612kn/s - Athlon XP 2.50GHz (Barton) 32 bit >>>1350kn/s - Athlon 64 1.80GHz (San Diego) 32 bit >>>1209kn/s - Pentium 4 3.0GHz (Northwood) 32 bit >>>1095kn/s - Athlon XP 2500+ 1.83GHz (Barton) 32 bit >> >>Thanks, Aaron. The last line corresponds to my system. I got 1089 on my Barton. > >Do you know if the P4-3GHz you have is a Northwood or Prescott? I think the >Prescotts can be up to 20% slower than Northwoods at chess, unfortunately. Could >you test yours and see how it compares? Thanks. I'll tell you tomorrow.
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