Author: Vincent Diepeveen
Date: 15:25:19 02/16/04
Go up one level in this thread
On February 16, 2004 at 13:28:21, Robert Hyatt wrote: >On February 16, 2004 at 12:08:28, Vincent Diepeveen wrote: > >>On February 16, 2004 at 12:02:16, Robert Hyatt wrote: >> >>>On February 16, 2004 at 11:30:57, Jorge Pichard wrote: >>> >>>>I still don't understand why Fritz nor Shredder have not been able to get an AMD >>>>sponsor, since 95% of the times it is sponsored by company that runs Intel >>>>inside. They need to get a different sponsor in order to beat Hydra in the World >>>>Championship. >>>> >>>>Hydra gets effectively around 4 million nodes a second >>>> >>>>I am very sure that a Quad opteron for a software program is >>>>faster than 4 fpga cards 30Mhz are. >>> >>>quad opteron box is NUMA. There are some issues there that have to be addressed >>>by anyone using such a box. Just taking a pure SMP program and dropping it in >>>may not produce such good results. Dual opterons are a bit easier to use. >> >>It works SMP great too. The latency when using it SMP is still faster than quad >>xeon chipset can deliver to you. > >No it isn't. A single cpu has a latency in the 60ns range. Dual is 60 for >local, 120 for remote. Go to 4-way and you get 60 for local, 120 for two of the >other banks, 180 for the last bank. >That is for a single memory reference. Assuming a TLB hit. IF you get a TLB >miss you _die_ just as you do anywhere, except that it is possible that the I didn't know Crafty nowadays was streaming sequential and that you only are multiplying nowadays matrice. >memory map tables are in remote memory as well, which means that your memory >access time (not latency) turns into 3x or 4x what it should. Opteron uses a >3-level map because of the 48 bit virtual address space. That means you do >three extra memory reads when you suffer a TLB miss. >My dual xeon has 150ns latency. TLB misses turn that into 450. The Opteron has >much more variability. 60ns on a TLB hit, up to 720ns for a TLB miss where the >page tables are in remote memory. >>Even without PGO and using old GCC version SMP version from diep gets a lot of >>nps at that box slightly less than it gets at a 8 processor Xeon. the numa >>version a lot less (not sharing evaluation tables nor pawn tables and the numa >>version tested wasn't sharing qsearch hashtables either). >> >>See www.aceshardware.com for diep SMP tests at quad opteron boxes. > >Don't need to. I have my own quad opteron numbers with things done right... >Whether you get good numbers with no work or not, you get _better_ numbers when >memory is done right. And it can be _significantly_ better. From experience. Well multiprocessing is way faster of course than multithreading at such machines, that includes 2-4 itaniums too. Your thing is continuesly busy with cache coherency, multiprocessor applications don't suffer from that of course. DIEP is multiprocessor. >> >>>Another issue is that AMD will likely want to see real 64 bit applications. >>>That is why they developed an interest in Crafty, in fact, because it really >>>needed the 64 bit internal stuff the opteron offers. Fritz, et al don't need >>>nor will they use this particular part of the opteron... >>> >>> >>>> >>>>Fritz and Shredder run in Paderborn on an identically constructed Transtec >>>>diagram workstation with two Intel each Xeon processors with 3,06 Ghz and 2 >>>>gigabyte memory. Deep Fritz will also count over 1 gigabyte Hashtabellen and >>>>with 2 to 2.3 million position/second for instance a search depth on 14 to 16 >>>>sections will reach, in the final game by means of 20 sections, strongly >>>>dependent on position and material. >>>> >>>>When ordered a Quad Opteron cost perhaps $45k and fpga cards cost only $3000 a >>>>card and a 4 node cluster Quad Xeon 3.06Ghz costs less than $45k. >>>> >>>>Here are some comparison of a Dual Opteron versus a Dual Xeon: >>>>http://www.gamepc.com/labs/view_content.asp?id=opt248vsxeon32a&page=5
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