Author: Vincent Diepeveen
Date: 22:54:55 04/07/03
Go up one level in this thread
On April 07, 2003 at 22:17:44, Charles Worthington wrote:
charles
a) measuring bandwidth the AMD duals get a bit more than the Xeon duals.
b) theoretic bandwidth of the xeon mobo's is bigger but that's theory. i
can tell you a lot about theory and computers. example. the teras machine
at which DIEP runs at is having 1 terabyte bandwidth a second. I will not say a
word more. read the specs yourself and let me know if they confuse you.
1024 processors of course and such...
I know other machines as well at which the banwdith is also in the tens of
gigabytes a second up to a hundred gigabytes a second and that's a bit more than
it has too.
no one checks ever.
in theory latency of systems is like 0.5 usec and so on. Even bob claimshis
network is 0.5 usec a message.
All bla bla.
that's all manufacturer bla bla.
Brutus is not going to run on the paderborn machine because the practical
latency of it is like 8 us.
theoretic latency at teras machine with 25 ns routers is 435 ns. however SGI
told me it has 50 ns and i count on a latency of 1200 ns to get a word from
other side of machine.
Still if it is 1500 ns that's a factor 6 faster nearly than what the paderborn
machine has where brutus was supposed to run at.
It took 2 days of discussing about parallellism with me, ulf lorenz and chrilly
odnninger before i started to realize that i could talk optimistic till the end
of the year and still they wouldn't get much chessprograms to run parallel at
that paderborner cluster machine. 8us sucks ass for a supercomputer as latency.
Note that machine is in top500.org even and not too low placed either.
This where the superb SGI latency, theoretically like 435 ns. is just factor 3
off what i feel it is.
on paper that paderborn machine is 0.5 us latency .... ...but it is 8.0 us if
you measure a ping on it!!
In that respect the x86 dudes are no better. in fact we talk about even more
money with regard to x86 cpu's than when we talk about these clusters or 0.5
billion dollar supercomputers.
For computerchess K7 rocks and it will be until the P4 moves to 0.09 or prescott
gets released, that it is faster for the average chessprogram.
Your measurement of 35% is off by a large margin.
If i measure diep then a 4 processes 2.8Ghz Xeon == 2 processor K7. in NODES A
SECOND. not in actual search depth. there the k7 wins.
I calculated a 3.06Ghz dual Xeon is equal to dual K7 2.2Ghz.
Now there is 166Mhz bus K7s. Cool. Cool. Let's run them dual they for about 1/3
of the price of a 1000 euro Xeon 3.06Ghz here is ;)
>On April 07, 2003 at 21:49:17, Aaron Gordon wrote:
>
>>On April 07, 2003 at 19:24:08, Charles Worthington wrote:
>>
>>>On April 07, 2003 at 19:13:50, Anthony Cozzie wrote:
>>>
>>>>Maybe you've never seen a real AMD system. I have 2 Athlons with HyperThreading
>>>>enabled (yes, Athlons *do* have it, its not documented and I had to do a little
>>>>soldering). With my liquid nitrogen cooling, they reach 2.93 GHZ stably. In
>>>>this position
>>>>
>>>>[D]rn3rk1/2p2pp1/bn2p2p/3qP1B1/1bpPN3/5N2/1PQ1BPPP/R4RK1 w - - 0 15
>>>>
>>>>my system reaches 4727 knps. I'd like to see your Xeon do the same, and I notice
>>>>you haven't posted any screenshots. Stop living in the past Mr. Worthington.
>>>>Your "new" Xeon is only good for watching TV, serving porn, and heating your
>>>>room. Thats the problem with Intel technology. It becomes obsolete so quickly.
>>>>
>>>>Regards,
>>>>anthony
>>>
>>>
>>>I just emailed you the actual screenshot. I do not know how to post a photograph
>>>here. Sure i can hit 5777kN/s but not sustained and you cannot sustain 4727kN/s
>>>with deep fritz 7. Post the fritzmark result here using deep fritz 7. And if you
>>>could sustain 4727kN/s with deep fritz then i suspect you would be the first to
>>>come to the server for that ten game match. Talk is always cheaper than action.
>>>
>>>Sincerely, Charles
>>
>>He's messing with you. Athlons don't have hyperthreading (and I'm glad they
>>don't), and any soldering he'd have to do would be replacing mosfets and
>>capacitors on the motherboard to support the wattage of two chips near 3GHz.
>>Highest I've seen a dual Athlon is 2.6GHz. Yes, this would smoke any Xeon if
>>you're wondering.
>>
>>When you consider two Xeon 2.8's get about 2.1 million nodes/second in Crafty
>>and my single 2.5GHz AthlonXP gets about 1.8 million, you can easily guess what
>>a dual XP-2.6GHz would do to even a dual Xeon 3.06.
>
>Yes Aaron and that was my point. We can overclock all day. AMD's are not the
>only overclockable processors. Xeons can be overclocked as well by one who is
>knowledgable enough to do so. I am discussing factory, out of the box systems.
>It seems unreasonable at best to compare a factory machine to one which is
>overclocked unless you overclock them both for a comparison. I am trying to deal
>with the figures I see daily and not some of the fantasy figures I have seen
>posted here. The ability to build such a system and actually building one are
>two entirely different things. In practice they are not often what they seem
>they will be on the drawing board. Certainly I am no computer expert but i am
>fairly certain that the speedup resulting from overclocking is limited to the
>available bandwidth on the motherboard. To my knowledge AMD does not have a
>board with 4.1GHz bandwidth (of course I may be wrong). So I am thinking that
>there may be some bottlenecks that will slow that system down a bit. The bottom
>line is that they are both fine processors. I love AMD machines and I lose many
>games to them on the server so I know they can perform. Yes my nps are higher by
>some 35% than the 2600MP but I still lose games to them. I would not hesitate
>one bit to buy any processor made by amd. I know you like to overclock and I
>repect that. Personally it is not something that I care for but that doesn't
>mean that I am right. It's more a matter of preference than right or wrong I
>think. You and I have had some nice sparring matches over this in the past :-)))
>and I think we should just agree to disagree on that one issue. But please never
>think that I have anything against AMD. Had that been an overclocked Xeon the
>post would have read Xeon instead of AMD. I was thinking that it was a glitch in
>the cpu that caused the blunder but apparently it was shredder himself moving
>too fast in a bit of time trouble.
>And, yes, I gave my apologies to the cpu. I apologize if I have seemed
>confrontational at times because i certainly do not intend to be. I am just
>opinionated I guess. :-) have a nice evening Aaron.
>
>Sincerely, Charles
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