Author: Vincent Diepeveen
Date: 14:24:16 01/20/01
Go up one level in this thread
On January 20, 2001 at 14:13:03, Robert Hyatt wrote: >On January 19, 2001 at 18:19:51, Vincent Diepeveen wrote: > >>On January 19, 2001 at 09:13:57, David Wilke wrote: >> >>>It has been stated by Robert many times that Crafty is blazing fast on an Alpha >>>processor. >>> >>>If this is the case, why wouldn't he use Alphas to run Crafty on the chess >>>servers instead of the big gun Xeons? >>> >>>What would be the actual cost of a Quad processor Alpha machine? >>> >>>And how much faster would Crafty be on that hardware? >> >>Recently (november) a dual mainboard came out for alpha at 866Mhz. >>Around 2500us$ ONLY for the motherboard. >>And correct me if i'm wrong, but it doesn't give a hardware 2.0 speedup. >> >>A cool MSI dual 694d motherboard allows processors (PIII fcpga) at >>like 1Ghz or above. It's $200 at most. >> >>So it's realistic to say alpha's are about 10 times pricier. >> >>A 16 processor alpha recently sold for 8.5 million dollar. >>I forgot the speed of the alpha's on that system. somewhere between 450 >>and 600 Mhz i think. >> >>Also it's not realistic to assume that we'll see alpha's in the stores >>breaking the 1 Ghz barrier in dual motherboards. >> >>If a dual alpha 21264 would be not too expensive i might just for >>fun buy one, but just $2500 for the motherboard to start with is >>not exactly big fun. >> >>That's out of my price range for sure. The 866Mhz speed i don't >>even complain about as it's not realistic to expect any production >>64 bits machine with so many registers like the alpha has to >>get over 1 Ghz. > >Digital has had alphas running over 1ghz for quite a while. However, their >lowly 600mhz processor blows off anything Intel can offer... floating point, >integer, memory bandwidth, you-name-it... a 21164 alpha had 8kb L1 cache. though my program is using 'int' everywhere, it's using a lot of code for its evaluation. Especially a lot of tables to look up scores. a 633Mhz 21164 performed like a PII at 380Mhz for DIEP a few years ago. But for 2388$ just for a dual mainboard that perhaps in hardware already doesn't get a 2.0 speedup over a single cpu, it's hard to imagine how much faster an 21264 is for my DIEP. Those integer speed tests never were a good measure for my software. I'm also talking about some security programs that encrypted a few texts. They flew on the alpha because of its 64 bits wide registers, but if i compiled the 32 bits version and compared that with PII, then the PII was even faster on that integer multiplying arrays thing, even though no PII instructions were used to eliminate branches. No program i compiled myself ever was faster on alpha when a fair comparision was done. I don't doubt that the 21264 is faster as a PII, but let's do a fair compare. Fastest factory buyable processor which is from the same generation (so a P4 1.5Ghz is not a fair compare) as the 21264 is a K7 at 1.2Ghz (so i'm not talking about overclocking it to 1.6Ghz as some people managed but about the speed at which they get sold). What is the fastest single cpu alpha 21264 as it leaves factory, 866Mhz? On paper seen the alpha can at most be 25% faster as a K7 as its only advantage is that it can do 4 instructions a clock versus K7 3, but it has of course a WAY bigger branch misprediction penalty. So i see no way to outgun a K7 at 1.2Ghz by a big margin. Now let's go on to the dual. Fastest clock you can get a dual now is a slot1 PIII800 RDRAM dual overclock it with a peltier elements to 1.1Ghz. Versus dual alpha 21264 with the only 2 months ago released motherboard 2000+ at 866Mhz. First question: how much hardware penalty do 2 alpha processors get for cooperating together? I remember rumours that they don't give a 2.0 hardware speedup because of some communication speed issue. Is that still true or only a rumour? In my eyes no way this system however is going to kick butt of the P3-cumine by a big margin. And we need to very clearly realize that despite the big money alpha costs that this 866Mhz dual motherboard only was released end NOVEMBER 2000. If 32 to 64 bits speedup is no big deal for a program then this dual alpha is already slower as the fastest dual K7 or PIII when you can buy it in the stores! > > >> >>It's more realistic to say that it might take 2 years before we >>see that. AMDs will be running probably dual then at 2 Ghz for >>less as 1/10 of alpha prices.
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