Author: Aaron Gordon
Date: 12:47:01 01/16/03
Go up one level in this thread
On January 16, 2003 at 10:59:33, Robert Hyatt wrote: >On January 16, 2003 at 03:26:13, Aaron Gordon wrote: > >>On January 15, 2003 at 21:29:34, Robert Hyatt wrote: >> >>>On January 15, 2003 at 19:04:36, Aaron Gordon wrote: >>> >>>>On January 15, 2003 at 18:14:50, Jorge Pichard wrote: >>>> >>>>>On January 15, 2003 at 17:43:47, Jorge Pichard wrote: >>>>> >>>>>>On January 15, 2003 at 15:21:00, Robert Hyatt wrote: >>>>>> >>>>>>>On January 15, 2003 at 12:56:07, pavel wrote: >>>>>>> >>>>>>>>Robert, >>>>>>>> I must have missed this in your earlier discussion, but how much >>>>>>>>speedup are you getting on this Xeon? Did you replace your older ones with the >>>>>>>>new ones already? >>>>>>>> >>>>>>>>Cheers, >>>>>>>>pavs >>>>>>> >>>>>>> >>>>>>>I simply replaced my quad 700 with a dual 2.8. It is somewhere around 2x >>>>>>>faster, >>>>>>>overall... >>>>>> >>>>>> >>>>>Therefore, the 8x 1000 Mhz used vs Kramnik is roughly almost the same speed as >>>>>the newer dual Xeon 2.8 Ghz. >>>>> >>>>>PS: I'm NOT comparing these two systems Mhz Per Mhz since 8x1000 = 8000 Ghz, >>>>>whereas 2 x 2.8 = 5.6 Ghz, but the performance difference should be roughly >>>>>equal using the Newer Dual Xeon 2.8/533. >>>>> >>>>>Pichard >>>> >>>> >>>>I highly doubt that. You seem to be forgetting that the P3's are faster MHz for >>>>MHz than the Pentium 4 chips. It roughly takes a P4-1.6GHz to equal one P3-1GHz. >>> >>>That isn't true in my case. My quad xeon 700 was a PIII-based xeon >>>box. My dual 2.8 is almost exactly twice as fast, which is what the >>>clocks say should happen. >> >>Actually, figuring the speed up into it... 4 p3 chips have a speedup factor of >>3.1x. 700 * 3.1 = 2170MHz and according to you (I remember the message well) you >>stated with the Intel C compiler your Quad got 1.6mn/s. Dual 2.8GHz w/ SMT >>should get a speedup of around 2.21 over 1 cpu w/o SMT. This is (1+(2-1)*0.7) * >>1.30 (30% boost from SMT). Now, 2800 * 2.21 = 6188MHz. This isn't the "total >>MHz" of course, whats actually being used from Crafty. Anyway, as I said in the >>previous message every post I've seen you're showing numbers around 2mn/s for >>the dual 2.8... now.. > >The problem with the above is that you are calculating the speedup for _crafty_. > Did >you specifically want to use crafty? Or was your question "which machine is >really >the fastest assuming that the algorithms used are optimal?" You continually say all you use is Crafty and that you got the machine for that purpose. Everything I did here was for Crafty & only Crafty. >The answer to the latter question is different from the first question's answer. > >The number I quoted was raw NPS, which is simply a raw performance indicator. >It doesn't necessarily mean that the dual is faster or slower than the quad for >chess, >although, in reality, they seem to be equal because the dual _still_ has to use >four >threads to take advantage of SMT... > > > > >>P3's @ 2170MHz = 1.6mn/s >>P4's @ 6188MHz = 2.0mn/s >>If you don't add the SMT as MHz you still get.. >>4760MHz, 2.0nb/s (2800*1.7) >>119% more cycles for what, 25% increase in performance? >> >>Now, the clocks say what again? ;) >> >>>>Also, about the "400/533mhz" bus business, it's not actually 400mhz or 533mhz. >>>>It's just quad pumped (four data transfers per cycle). Thus a "400MHz" p4 bus is >>>>actually 100MHz and a "533" is 133. Same goes for DDR (double pumped, two >>>>transfers per cycle). I prefer DDR over RDRAM. DDR is much more efficient >>>>(actually does what it's rated for). The PC1066 RDRAM only pulls around 3.2gb/s >>>>actual but 240MHz(480) DDR hits 3.7gb/s easily (on an Nforce2 board). ;) >>> >>>If you think about it, does it matter? 1 transfer 400M times a second, or >>>4 transfers 100M times a second? It is simply semantics, not practical speed. >>> >>>BTW my xeon box (2.8 x 2) is DDR ram, not rambus... I'm not a fan of rambus >>>at all except for certain kinds of streaming memory applications... >> >>It does to me, I like everything to be right. I run my (DDR) bus at 183MHz, if I >>said I was running a "366MHz fsb" I would be what? Wrong.
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