Author: Aaron Gordon
Date: 08:16:57 03/20/03
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On March 20, 2003 at 10:48:21, Robert Hyatt wrote: >On March 20, 2003 at 03:38:14, Aaron Gordon wrote: > >>On March 20, 2003 at 02:42:54, Matt Taylor wrote: >>>The latency of a memory access on Clawhammer is at -least- 40 ns (the lowest >>>figure I have seen reported). I saw another figure of 70-80 ns. I am not sure >>>which one is correct. On my dual-Athlon, I get 133 ns per Sciencemark. Here are >>>timings I obtained for an nForce 2 board: >>>http://www.talkchess.com/forums/1/message.html?290002 >>> >>>I do not doubt that better can be obtained. Aaron got as low as 68 ns with a 220 >>>MHz bus and fast ram. >> >>Just for the fun of it I retested, slightly faster fsb & timings. Here's what I >>came up with. AthlonXP 2.46Ghz, 223fsb, 2.5-3-3-7 timings, single-channel DDR >> >>Memory latencies in nanoseconds - smaller is better >> (WARNING - may not be correct, check graphs) >>------------------------------------------------------------------ >>Host OS Mhz L1 $ L2 $ Main mem Guesses >>--------- ------------- --- ---- ---- -------- ------- >>p5 Linux 2.2.14- 2464 1.2200 8.1320 65.3 >> >> >>=) > > >The next question: will that clock speed pass a _strong_ memory diagnostic? > >:) Yes, it's been running seti@home over night actually (very memory intensive). I also ran 2 passes of "Memtest86" which is extremely sensitive. Luckily for me all was perfectly stable. I checked it this morning.. still chugging along. I'd really like to try to get below 60ns, even if it's just 58-59ns. This would be quite an ordeal, though, as it would require me running 245-250fsb(490-500DDR). I'd need to put the peltier I have on the chipset and bolt down a large heatsink/fan or perhaps liquid cooling ontop of that. That alone wouldn't do it, either. I'd also have to push the VDD voltage up from 1.85v to 2.0-2.1v. Originally it was 1.58 and I pushed it up to 1.85v (still within the Nforce2 specs). Any more though and it'd be going out of spec.
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