Author: Uri Blass
Date: 04:31:45 02/17/04
Go up one level in this thread
On February 17, 2004 at 07:21:25, Vincent Diepeveen wrote: >On February 17, 2004 at 06:35:10, Uri Blass wrote: > >>On February 17, 2004 at 06:19:00, Vincent Diepeveen wrote: >> >>>On February 16, 2004 at 22:09:28, Robert Hyatt wrote: >>> >>>>On February 16, 2004 at 18:25:19, Vincent Diepeveen wrote: >>>> >>>>>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. >>>> >>>>I didn't know that _all_ you do is random hash probes... In my program, I only >>>>do one call to HashProbe() per node. I do a _lot_ of other stuff per node as >>> >>>So you are denying that each probe you do to hashtable is random and you're >>>saying that you are not using Zobrist in Crafty? >>> >>>Are you or are you not? >>> >>>>well, from generating moves, to ordering moves, to using the Swap() (SEE) code, >>>>to evaluating positions, and so forth.. Most of those are not going to blow the >>>>TLB. Which means that for Crafty, memory access time is going to be almost >>>>exactly memory latency time. Only one reference per node requires the 3-4 >>>>access virtual-to-real translation overhead. Out of _thousands_... >>> >>> >>> >>>> >>>> >>>>> >>>>>>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. >>>> >>>> >>>>No it isn't. You just don't know how to do multi-threading, apparently. I do >>> >>>You trivially have no idea how advanced that microprocessors are nowadays. >>>You're still toying with the 68000 designs i bet. >>> >>>By the way the 68000 has been named like that because it uses 68000 gates. >>> >>>Nowadays processors have tens of millions of transistors and work very complex >>>and you have not even a remote clue on how they work. >>> >>>>and it is working just fine. And is actually an efficient way to do things as >>>>Eugene has told you many times. Shared egtb buffers is one reason. There is no >>>>reason for threads to be bad... >>> >>>So you do not know how to share memory when running multiprocessor? >>> >>>> >>>> >>>>> >>>>>Your thing is continuesly busy with cache coherency, multiprocessor applications >>>>>don't suffer from that of course. DIEP is multiprocessor. >>>> >>>>My thing is _not_ continually busy with cache coherency. You just don't >>>>understand how "my thing" works, apparently. >>>>Perhaps you should look at your results, when trying to figure out whether what >>>>you are doing is better than another approach. My approach seems to be doing >>>>just fine, based on recent results and performance measurements... >>> >>>I see that Crafty will never end above me in a world champs because you are >>>fearing to join there as you would get crushed like an ant there. >> >>I see that you will never learn that people who do not join world championships >>may do it for other reasons than fear. >> >>There are other tournaments like the CCT and Crafty finished above some >>commercial programs like Hiarcs or Ruffian Or Rebel. >> >>Time control is different but generally the difference in elo between 45+10 and >>tournament time control is not so big to say that crafty has no chance against >>the commercial programs. >> >>Uri > >In short you are claiming that in world champs 2004 you will get won positions >against junior and others too which will end only in a draw because of some >endgame bug. > >I'll tell you, that *won't* happen. You will get crushed like an ANT there too. >No beginner openings will be played there. I did not claim it. It is possible that I will get a winning position against Junior but I do not expect it to happen. Movei was simply lucky against Junior and I do not expect luck to happen every game. Uri
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