> On Mon, 19 Nov 2012, Vincent Diepeveen wrote: > >> If you measure memory latency at all 8 cores at the same time, it's >> even more horrible. > > Thanks for a remarkably clear and useful reply, Vincent. This nearly > precisely mirrors my own measurements with a more floating point > intensive task. The larger i7-3770 cache and its 8 operational contexts > (it is a four core system but it maintains two completely independent > contexts per core, IIRC) seem to give it an overwhelming advantage over > the FX with its eight "real" cores but much smaller cache. Interesting > to see that this continues with the (I assume) integer/logic intensive > chess code.
This may be of interest: http://www.clustermonkey.net/Benchmarking-Methods/benchmarking-a-multi-core-processor-for-hpc.html > > Basically, the i7 looks like a butt-kicking good processor, with the one > problem being that it doesn't look like a multiprocessing cpu (at least > I can't find a dual i7 motherboard, although in principle it appears to > be possible, leaving one with Xeons that don't LOOK like they would > perform as well although I'd be interested in information on that as > well. > > At the moment, single processor i7's look like they might actually be > the world's fastest, at least on a per core basis. OTOH, it might well > be that putting two of them on a single board would horribly saturate > the memory bus and cause memory management collisions and worse and cost > them their advantage. > > I'm getting ready to do some very data intensive stuff -- terabyte-scale > datasets being chewed to pieces basically -- to the point where my > "cluster" will probably be a pile of RAIDs each with its own private > copy of the datasets in questions and equipped with an i7 motherboard, > which seems odd somehow (as the i7 motherboards aren't generally > configured as "server" motherboards) but the Xeons all run at lower > clock and are older technology. Intel has a single socket Xeon (E3-12XX series Sandy/Ivy-Bridge) and will work on single socket motherboards. Mostly designed for the small office/home server these have more "server" features, basically ECC, and cost slightly more than the i-5/7 series. They are lower power as well. -- Doug > > Comments from anyone else? > > rgb > >> >>> I would have hoped that AMD would dig in an innovate and >>> regain at least parity if not the lead, because it is good for the >>> industry for Intel to have serious competition, but while Intel could >>> make money and survive as second best to AMD, AMD can't make any money >>> as second best to Intel... >> >> We must split of course the 2 worlds of HPC performance. >> In fact htere is 3 but let's do a rough 2 world division >> >> a) floating point or vectorized performance (can be integers as well) >> >> We skip A : the manycores have won there. >> >> b) integer performance non-vectorized >> >> For integers and branches if i take a huge program like Diep. >> >> http://www.lostcircuits.com/mambo//index.php? >> option=com_content&task=view&id=105&Itemid=42&limit=1&limitstart=13 >> >> More is better. >> >> i7-3960X-EE : 2.0 Million chess positions a second (12 logical cores) >> i7-980x turbo: 1.85 Million chess positions a second (12 logical cores) >> i7-3770k: 1.47 million chess positions a second (8 logical >> cores) >> AMD Phenom X6 1100T : 1.34 million chess positions a second (6 cores) >> AMD Phenom X6 1090T : 1.30 million chess positions a second (6 cores) >> FX-8150 : 1.22 million chesspositions a second (8 mini cores) >> >> The FX-8150 is AMD's latest 'bulldozer' CPU. >> >> The problem is the new generation FX-8150 at a NEW process >> technology, with 2 billion transistors or so (caches counted >> - the initial press release from AMD - not the later one where they >> creatively not counting things reached 1.2 billion) is not beating >> their own old design. >> >> Furthermore another big problem is power usage. >> >> http://www.lostcircuits.com/mambo//index.php? >> option=com_content&task=view&id=105&Itemid=42&limit=1&limitstart=6 >> >> Under full load: >> >> Phenom X6 1090T : 69.6 watt, >> Phenom X6 1100T : 92 watt >> >> We see how the 1100T already was clocked a tad too high by AMD, which >> explains the huge power increase. >> >> Now the FX-8150 : 115.2 watt >> >> As if Law of Moore garantueeing progress doesn't exist... >> >> As for you, in many benchmarks you did do maybe multiplication was >> important. Each minicore has its own multiplication unit. >> Sounds good huh? >> >> So far the good news: the problem is: it's also over 2 times slower >> that unit... >> >> Please note that bulldozer does have AVX. From benchmarks we know >> that both intel as well as AMD with this bulldozer, >> had tried to optimize performance for game. Games using AVX especially. >> >> It's not doing bad there in fact. Worse than the quadcore intels. I >> don't want a quadcore chip though. >> I want a million cores. >> >>> >>> rgb >>> >>>> >>>> -- >>>> Doug >>>> >>>> -- >>>> Mailscanner: Clean >>>> >>>> _______________________________________________ >>>> Beowulf mailing list, Beowulf@beowulf.org sponsored by Penguin >>>> Computing >>>> To change your subscription (digest mode or unsubscribe) visit >>>> http://www.beowulf.org/mailman/listinfo/beowulf >>>> >>> >>> Robert G. Brown http://www.phy.duke.edu/~rgb/ >>> Duke University Dept. of Physics, Box 90305 >>> Durham, N.C. 27708-0305 >>> Phone: 1-919-660-2567 Fax: 919-660-2525 email:r...@phy.duke.edu >>> >>> >>> _______________________________________________ >>> Beowulf mailing list, Beowulf@beowulf.org sponsored by Penguin >>> Computing >>> To change your subscription (digest mode or unsubscribe) visit >>> http://www.beowulf.org/mailman/listinfo/beowulf >> >> _______________________________________________ >> Beowulf mailing list, Beowulf@beowulf.org sponsored by Penguin Computing >> To change your subscription (digest mode or unsubscribe) visit >> http://www.beowulf.org/mailman/listinfo/beowulf >> > > Robert G. Brown http://www.phy.duke.edu/~rgb/ > Duke University Dept. of Physics, Box 90305 > Durham, N.C. 27708-0305 > Phone: 1-919-660-2567 Fax: 919-660-2525 email:r...@phy.duke.edu > > > > -- > Mailscanner: Clean > -- Doug -- Mailscanner: Clean _______________________________________________ Beowulf mailing list, Beowulf@beowulf.org sponsored by Penguin Computing To change your subscription (digest mode or unsubscribe) visit http://www.beowulf.org/mailman/listinfo/beowulf
