From chemistry-request |-at-| ccl.net Mon May 16 18:24:01 2005 Received: from main.chemistry.unina.it (main.chemistry.unina.it [143.225.167.251]) by server.ccl.net (8.13.1/8.13.1) with ESMTP id j4GMNt7i024791 for ; Mon, 16 May 2005 18:23:56 -0400 Received: from localhost by chemistry.unina.it (PMDF V6.2 #30554) with ESMTP id <0IGL00A01T05SM _(a)_ chemistry.unina.it> for chemistry _(a)_ ccl.net; Tue, 17 May 2005 00:26:29 +0200 (MET DST) Date: Tue, 17 May 2005 00:26:29 +0200 (MET DST) From: Luigi Cavallo Subject: Summary Opteron vs Nocona To: chemistry _(a)_ ccl.net Message-id: MIME-version: 1.0 Content-type: TEXT/PLAIN; charset=X-UNKNOWN X-Spam-Status: No, score=0.8 required=5.0 tests=AMATEUR_PORN autolearn=no version=3.0.3 X-Spam-Checker-Version: SpamAssassin 3.0.3 (2005-04-27) on server.ccl.net Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from QUOTED-PRINTABLE to 8bit by server.ccl.net id j4GMO17i024801 Dear all, this is the collection of all the very useful responses I got. making a long story short, it seems that opterons are much more balanced than noconas, and that they are the clear winner when memory bandwith (or memory in general) is of relevance. Noconas seems to be better when you only need floating point speed. However, there's one point about opterons. AMD just announced dual-core cpus, which should perform far better than the single-core shipped now. I contacted resellers here in italy, and they say that dual-core cpus will be shipped after the summer. If you buy opetrons now they can sell you single-core. Is this true ? Any out of there has been able to buy AMD with dual-core cpus as the 275 ? By, Luigi Hi, we are going to invest some money for a few computers, and we have to make a decision between the AMD-Opterons and the Intel-Nocona. What's better ? We are experienced with the Opterons, but we have no idea about the Noconas... Major codes to run on them will be classical QM packages as ADF, G03, TM, some AIMD as CPMD, and possibly some classical MD as gromacs. Thanks, Luigi -= This is automatically added to each message by the mailing script =- To send e-mail to subscribers of CCL put the string CCL: on your Subject: line and send your message to: CHEMISTRY _(a)_ ccl.net Send your subscription/unsubscription requests to: CHEMISTRY-REQUEST _(a)_ ccl.net HOME Page: http://www.ccl.net | Jobs Page: http://www.ccl.net/jobs If your is mail bouncing from ccl.net domain due to spam filters, please use the Web based form from CCL Home Page -+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ =========================================================================== > From diep _(a)_ xs4all.nl Tue May 17 00:04:20 2005 Date: Sat, 07 May 2005 22:59:39 +0200 From: Vincent Diepeveen To: Eugen Leitl Cc: cavallo _(a)_ chemistry.unina.it Subject: CCL:Opteron or Nocona ? (fwd fromcavallo _(a)_ chemistry.unina.it) hi Eugen, Nocona has 4 cycle L1 cache %-% at %-% 1 slot and compares well to prescott core. Very ugly bad for most software. Its IPC for all my software is lower than the old Xeons. benchmark of latest prescott dual core P4 versus dual core opterons: http://www.sudhian.com/showdocs.cfm?aid=667&pid=2543 Please note Nocona is not dual core yet. Opteron is dual core. So practical opteron like 3 to 4 times faster for most software. If software in question uses SSE2, then just hack the code a bit, so that SSE2 works, that usually speeds up incredible for Opteron, especially latest generations. The few benchmarks where Nocona is faster than Opteron, without exception they use software where the SSE2 has been enabled for Nocona and disabled for opteron. Way to compare. Real amateuristic compares. You'll have to wait until Q1 2007 before there is a good new Xeon processor i guess. www.pricewatch.com for prices in shops of the different cpu's. Very cheap to buy in USA usually, even when living in europe. At most 20% import tax. Vincent =========================================================================== > From stuart.midgley _(a)_ anu.edu.au Tue May 17 00:04:31 2005 Date: Sun, 08 May 2005 13:02:36 +1000 From: Stuart Midgley To: Eugen Leitl Cc: Beowulf _(a)_ beowulf.org, Luigi Cavallo Subject: Re: [Beowulf] CCL:Opteron or Nocona ? (fwd from cavallo _(a)_ chemistry.unina.it) Morning It highly depends on your code and whether you are going to run more than a single cpu in a box. If you are only going to purchase single cpu boxes, I think they are more or less the same. If, however, you are going to run more than a single cpu box, I think it is fair to say, that the Opterons should give better performance. Just look at the spec rate fp base and you will see that a dual processor opteron system out perform the Nocona systems by a long way. Each opteron chip has its own memory controller. So, if you have 2 cpu's, you have 2 memory controllers and your memory bandwidth scales linearly. Nocona chips sit on a bus with a single memory controller. If you have 2 cpu's you still only have 1 memory controller, so each chip, on average, sees only 1/2 the memory bandwidth. The other issue is memory latency. Because the Opterons have the memory controller on the actual cpu chip, their latency to memory is very very low, which gives an effective increase in memory bandwidth. The Nocona chips have the memory controller off chip, so their latency is high, reducing effective memory bandwidth. There are other minor difference, but the memory sub-system is the one that gives the biggest performance difference. Stu. ================================================================================== > From chinet.pesch _(a)_ attglobal.net Tue May 17 00:04:41 2005 Date: Sun, 08 May 2005 07:32:30 -0400 From: "chinet.pesch _(a)_ attglobal.net" To: eugen _(a)_ leitl.org, beowulf _(a)_ beowulf.org Subject: RE: [Beowulf] CCL:Opteron or Nocona ? (fwd fromcavallo _(a)_ chemistry.unina.it) Resent-Date: Sun, 08 May 2005 15:31:06 +0200 Resent-From: eugen _(a)_ leitl.org Resent-To: cavallo _(a)_ chemistry.unina.it [ The following text is in the "iso-8859-1" character set. ] [ Your display is set for the "US-ASCII" character set. ] [ Some characters may be displayed incorrectly. ] ...to make a long story short: go for the opteron Paul Original Message: ----------------- From: Eugen Leitl eugen _(a)_ leitl.org Date: Sat, 7 May 2005 19:23:01 +0200 To: Beowulf _(a)_ beowulf.org Subject: [Beowulf] CCL:Opteron or Nocona ? (fwd fromcavallo _(a)_ chemistry.unina.it) ================================================================================== > From wharman _(a)_ prism.net Tue May 17 00:04:54 2005 Date: Sun, 08 May 2005 13:16:29 -0600 From: William Harman To: 'Luigi Cavallo' Subject: RE: Opteron or Nocona ? Luigi Have you considered PowerPC processors form Apple or IBM? Check out www.terrasoftsolutions.com Bill Harman, Salt Lake City office P - (801) 572-9252 F - (801) 571-4927 wharman _(a)_ prism.net billharman _(a)_ comcast.net skype: harman8015729252 ================================================================================== > From m.somers _(a)_ chem.leidenuniv.nl Tue May 17 00:05:01 2005 Date: Mon, 09 May 2005 09:38:06 +0200 From: mark somers To: Luigi Cavallo Cc: chemistry _(a)_ ccl.net Subject: Re: CCL:Opteron or Nocona ? [ The following text is in the "iso-8859-1" character set. ] [ Your display is set for the "US-ASCII" character set. ] [ Some characters may be displayed incorrectly. ] Dear Luigi Cavallo, we have recently purchased and setup a new Beowulf cluster here in Leiden, dedicated to run ADF and other DFT codes (Dacapo and Vasp) on it. We have found the Nocona's, in combination with the Intel compilers, to be the best combination especially for ADF and ADF-BAND. Before we decided to go for the Nocona's, we did try with two test machines, one being a dual-cpu AMD Opteron 246 (2.0 GHz) and the other being a dual-cpu Nocona (3.0 GHz). Tests showed that the AMD has, in general, a slightly better cache hierarchy and a better memory scalability, but also that the lack of compilers able to tune for the Opterons is severe. Of course we took the differences in cpu clocks into account. As it turns out, after having contacted the SCM people in Amsterdam, ADF can effectively use the SSE3 registers and cpu intruction set and that makes it run fast on the Nocona's. This, together with the prices being roughly the same, made us decide to go for the Nocona's. BTW, maybe this is known to you already, but Intel offers you their OpenMP capable compilers for free for academic use. The machine is up and running now in 64 bit mode and doing fine ;-). Maybe the information can help you in your decision. Best regards, Mark Somers. Dr. M. F. Somers Theoretical Chemistry - Leiden Institute of Chemistry - Leiden University Einsteinweg 55, P.B. 9502, 2300 RA Leiden, The Netherlands tel: +31715274437 mail: m.somers _(a)_ chem.leidenuniv.nl web: http://rulgla.leidenuniv.nl/Researchers/Somers.htm room: HB322 ================================================================================== > From m.swart _(a)_ few.vu.nl Tue May 17 00:05:09 2005 Date: Mon, 09 May 2005 09:55:13 +0200 From: Marcel Swart To: Luigi Cavallo Subject: Re: CCL:Opteron or Nocona ? [ The following text is in the "WINDOWS-1252" character set. ] [ Your display is set for the "US-ASCII" character set. ] [ Some characters may be displayed incorrectly. ] Dear Luigi, probably someone at SCM would be willing to give you some data on how ADF performs on both machines; all I remember from the bits and bats I've been told over the past months, is that the Nocona seems to be doing very well for ADF. dr. Marcel Swart Theoretische Chemie Vrije Universiteit Amsterdam Faculteit der Exacte Wetenschappen De Boelelaan 1083 1081 HV Amsterdam The Netherlands Tel +31-(0)20-5987619 Fax +31-(0)20-5987629 E-mail m.swart _(a)_ few.vu.nl Web http://www.few.vu.nl/~swart ^V^V^V^V^V^V^V^V^V^V^V^V^V^V^V^V^V^V^V^V^V^V^V^V^V^V^V^V^V^V^V^V^V^V^V^V^V^V^V^V^V^V^V^V ================================================================================== > From m.vanleeuwen _(a)_ clustervision.com Tue May 17 00:05:15 2005 Date: Mon, 09 May 2005 09:59:12 +0200 From: Matthijs van Leeuwen To: 'Gert Kruger' Cc: cavallo _(a)_ chemistry.unina.it Subject: RE: CCL:Opteron or Nocona ? Dear Gert & Mr Cavallo, Both the Intel Xeon EM64T (code-name "Nocona") and the AMD Opteron processor are fine for number crunching. The Nocona is slightly better at pure number crunching when memory bandwidth is not so important. When memory performance is important, the Opteron is the superior CPU because it has a superior memory bus. Both CPUs can be clocked down by the BIOS if they overheat, but this should not be possible when they run in a properly cooled room, even when running at maximum load for a long time. This recent press release lists some of our installations in 2004: http://www.clustervision.com/pr_2004_uk.html These include both Intel Nocona and AMD Opteron CPUs and all these installations are built do run all the time and at maximum load. ClusterVision is a hardware-independent cluster solution expert. We have no preference for AMD or Intel CPUs and always try to supply the CPU which is best for your applications. The servers we use are usually from Supermicro or Tyan, but we can also use other brands. Hope this is helpful. Don't hesitate to contact me for further questions. Kind regards, Matthijs __________________________________________________ Dr ir Matthijs van Leeuwen ClusterVision Tel NL: +31 23 5677510 / Tel UK: +44 870 080 1980 Mob NL: +31 6 41941992 / Mob UK: +44 7966 012215 Fax NL: +31 23 5677519 / Fax UK: +44 870 132 4332 Email: m.vanleeuwen _(a)_ clustervision.com Web: http://www.clustervision.com ================================================================================== > From alex.brown _(a)_ ualberta.ca Tue May 17 00:05:20 2005 Date: Mon, 09 May 2005 12:01:16 -0600 From: Alex Brown To: mark somers Cc: chemistry _(a)_ ccl.net, Luigi Cavallo Subject: Re: Intel compilers: was Opteron or Nocona ? Dear Mark, Luigi, and others, BTW, maybe this is known to you already, but Intel offers you their OpenMP capable compilers for free for academic use. I have seen this stated several times on the list. While I believe that this used to be the case, Intel has clarified their position on academic use of their non-commercial compilers. As taken from their FAQ page (http://www.intel.com/software/products/noncom/faq.htm) Q. I am engaged in academic research. Can I use the non-commercial product? A. If you, as an individual, are receiving any form of compensation for the research project (i.e., you receive a salary, or funding, etc.), you do not qualify for a non-commercial use license. However, you may qualify for the academic license (Click to academic page) Note that I do not have any affiliation with Intel nor does it bother me what individuals choose to do with their copies of the non-commercial compilers. However, I wanted to clear up what I think is a common misconception about their compilers. Cheers, Alex Alex Brown Assistant Professor Department of Chemistry University of Alberta Edmonton, AB T6G 2G2 http://www.chem.ualberta.ca/~abrown/ ================================================================================== > From mwill _(a)_ penguincomputing.com Tue May 17 00:05:25 2005 Date: Mon, 09 May 2005 13:49:09 -0700 From: Michael Will To: cavallo _(a)_ chemistry.unina.it Subject: compilers for em64t vs. opteron [ The following text is in the "ISO-8859-1" character set. ] [ Your display is set for the "US-ASCII" character set. ] [ Some characters may be displayed incorrectly. ] There are actually quite good compilers optimizing for the opteron out there. One from PGI and one from pathscale, both are commercial compilers for c++ and fortran90. We expect the opterons to outperform the em64t xeons across the board, but offer both to our customers. Michael -- Michael Will Penguin Computing Corp. Sales Engineer 415-954-2887 415-954-2899 fx mwill _(a)_ penguincomputing.com Visit us at the following Linux Shows! Bio-IT World Conference and Expo '05 Hynes Convention Center, Boston, MA May 17th-19th, 2005 Booth 201 ================================================================================== > From alex.brown _(a)_ ualberta.ca Tue May 17 00:05:29 2005 Date: Mon, 09 May 2005 12:01:16 -0600 From: Alex Brown To: mark somers Cc: chemistry _(a)_ ccl.net, Luigi Cavallo Subject: CCL:Intel compilers: was Opteron or Nocona ? Dear Mark, Luigi, and others, BTW, maybe this is known to you already, but Intel offers you their OpenMP capable compilers for free for academic use. I have seen this stated several times on the list. While I believe that this used to be the case, Intel has clarified their position on academic use of their non-commercial compilers. As taken from their FAQ page (http://www.intel.com/software/products/noncom/faq.htm) Q. I am engaged in academic research. Can I use the non-commercial product? A. If you, as an individual, are receiving any form of compensation for the research project (i.e., you receive a salary, or funding, etc.), you do not qualify for a non-commercial use license. However, you may qualify for the academic license (Click to academic page) Note that I do not have any affiliation with Intel nor does it bother me what individuals choose to do with their copies of the non-commercial compilers. However, I wanted to clear up what I think is a common misconception about their compilers. Cheers, Alex Alex Brown Assistant Professor Department of Chemistry University of Alberta Edmonton, AB T6G 2G2 http://www.chem.ualberta.ca/~abrown/ ======================================================================================= > From konstantin_kudin _(a)_ yahoo.com Tue May 17 00:05:32 2005 Date: Mon, 09 May 2005 19:01:04 -0700 (PDT) From: Konstantin Kudin To: mark somers , Luigi Cavallo Cc: chemistry _(a)_ ccl.net Subject: Re: CCL:Opteron or Nocona ? Actually, highly optimizing compilers for Opteron do exist (such as Pathscale). Even Intel Fortran 8.1 (either 32 or 64 bits) produces decent code for Opteron since Opteron is not as fragile as Pentium 4 in terms of which code it likes and which it does not. There is one specific situation where Nocona could come as a clear winner, but such cases are not too common. Basically, codes that run BLAS routines such as DGEMM for the majority of their runtime gain a lot on Nocona when the correct libraries are used. This is because both Opteron and Nocona run BLAS proportionally to the clock speed, so the much higher clocked Nocona wins (~3 vs ~2 Ghz). On the other hand, multi-processor Noconas can choke because of limited memory bandwidth, whereas Opterons under such circumstances do just fine. Last, here are some last year's Gaussian03 benchmarks, where both Opterons and Noconas were comparable: http://www.princeton.edu/~kkudin/g03_b5_tests_1.txt YMMV ... Kostya ======================================================================================= > From reuti _(a)_ staff.uni-marburg.de Tue May 17 00:05:36 2005 Date: Mon, 09 May 2005 23:11:44 +0200 From: Reuti To: Eugen Leitl Cc: Beowulf _(a)_ beowulf.org Subject: Re: [Beowulf] CCL:Opteron or Nocona ? (fwd from m.somers _(a)_ chem.leidenuniv.nl) Resent-Date: Tue, 10 May 2005 10:29:10 +0200 Resent-From: eugen _(a)_ leitl.org Resent-To: cavallo _(a)_ chemistry.unina.it [ The following text is in the "ISO-8859-1" character set. ] [ Your display is set for the "US-ASCII" character set. ] [ Some characters may be displayed incorrectly. ] Hi, Quoting Eugen Leitl : > ----- Forwarded message from mark somers > ----- > BTW, maybe this is known to you already, but Intel offers you their OpenMP > capable compilers for free for academic use. I understand the license terms of Intel a little bit different: a student may use the compilers for his/her homework for free and also OpenSource programmers. But as soon as the person using the compiler or the compiled binary get any payment for their work, you have to buy (an academic) license. Maybe the license terms changed again, but can please anyone clarify. =======================================================================================TIA - Reuti > From Christian.Boehme _(a)_ gwdg.de Tue May 17 00:05:44 2005 Date: Tue, 10 May 2005 11:41:46 +0200 From: Christian Boehme To: Luigi Cavallo Cc: chemistry _(a)_ ccl.net Subject: Re: CCL:Opteron or Nocona ? [ The following text is in the "ISO-8859-1" character set. ] [ Your display is set for the "US-ASCII" character set. ] [ Some characters may be displayed incorrectly. ] Dear Luigi, We recently purchased a 32 dual-processor Opteron (2GHz) cluster. We used CPMD and several artificial benchmarks on Opteron and Xeon (3GHz) machines to come to this decision. With CPMD we found that the advantage of the Opteron over the Xeon was very significant for 32-bit memory intensive applications running on both processors of a dual processor box (Intel compiler on both architectures). When using just one processor, the Xeon scored much better. As Intel has not changed the memory interface of the Nocona, I do not think this trend would be different for 64-bit applications. Regarding Fortran compilers, from our experience both the Intel and the Portland can now be used to make production quality 64-bit binaries for the Opterons. Best wishes Christian -- Dr. Christian Boehme GWDG Private: Am Fassberg Wilhelm-Raabe-Str. 15 37077 Gvttingen 37083 Gvttingen email: Christian.Boehme _(a)_ gwdg.de ChristianBoehme _(a)_ web.de phone: +49 (0)551 201-1839 +49 (0)551 3077000 fax: +49 (0)551 201-2150 +49 (0)551 3077077 ======================================================================================= > From maurice _(a)_ harddata.com Tue May 17 00:05:48 2005 Date: Tue, 10 May 2005 01:44:32 -0600 From: Maurice Hilarius To: beowulf _(a)_ beowulf.org Subject: [Beowulf] Re: CCL:Opteron or Nocona ? Resent-Date: Tue, 10 May 2005 18:00:15 +0200 Resent-From: eugen _(a)_ leitl.org Resent-To: cavallo _(a)_ chemistry.unina.it [ The following text is in the "ISO-8859-1" character set. ] [ Your display is set for the "US-ASCII" character set. ] [ Some characters may be displayed incorrectly. ] > >From: mark somers >Date: Mon, 9 May 2005 09:38:06 +0200 >To: Luigi Cavallo >Cc: chemistry _(a)_ ccl.net >Subject: CCL:Opteron or Nocona ? > >Dear Luigi Cavallo, > >we have recently purchased and setup a new Beowulf cluster here in Leiden, >dedicated to run ADF and other DFT codes (Dacapo and Vasp) on it. We have >found the Nocona's, in combination with the Intel compilers, to be the best >combination especially for ADF and ADF-BAND. > >Before we decided to go for the Nocona's, we did try with two test machines, >one being a dual-cpu AMD Opteron 246 (2.0 GHz) and the other being a dual-cpu >Nocona (3.0 GHz). Tests showed that the AMD has, in general, a slightly >better cache hierarchy and a better memory scalability, but also that the >lack of compilers able to tune for the Opterons is severe. Of course we took >the differences in cpu clocks into account. > > > LACK OF COMPILERS IS SEVERE? You apparently did next to no research on the subject. A simple Google search on the terms: "Opteron compiler" provides a wealth of information. GCC, Intel, Absoft, and especially Pathscale compilers are excellent for Opteron. New Revision E and dual core Opterons have SSE3. As for your comment about "taking the differences in CPU clocks into account" I am quite puzzled. Even Intel is now pushing "performance ratings". In current CPUs a comparison based on clock speed is nearly meaningless. >As it turns out, after having contacted the SCM people in Amsterdam, ADF can >effectively use the SSE3 registers and cpu intruction set and that makes it >run fast on the Nocona's. This, together with the prices being roughly the >same, made us decide to go for the Nocona's. > >BTW, maybe this is known to you already, but Intel offers you their OpenMP >capable compilers for free for academic use. > > No, they do not! They are only "free" for essentially hobbyist use. If you use them in a university or research cluster that violates the license. I think you had a nice relationship with the Intel reseller, and "drank the Kool-Aid" he gave you. Sorry to be harsh, but the statements you make above are so one-sided and uninformed, I had to speak out. For HPC the numbers are so overwhelmingly in favour of Opteron as to be virtually insurmountable. Before I get flamed, yes, I agree there are some codes that are better suited to the Intel CPUs. Just not the vast majority. Further, now that dual core Opterons are shipping, the whole game just got reset. Any advice you can give based on a purchasing decision made even 3 months ago is now so obsolete as to be virtually irrelevant. Here is a recent and fairly comprehensive comparison on the AMD versus the Intel single and dual core CPUs performance. http://techreport.com/reviews/2005q2/athlon64-x2/index.x?pg=1 The power consumption and heat production is especially telling. Add to that the fact that with dual cores the whole architecture just changed drastically and I think you will see that we now start over with "new rules". With our best regards, Maurice W. Hilarius Hard Data Ltd email: maurice _(a)_ harddata.com http://www.harddata.com/ ==================================================================================== > From eugen _(a)_ leitl.org Tue May 17 00:05:55 2005 Date: Tue, 10 May 2005 13:02:46 +0200 From: Eugen Leitl To: chemistry _(a)_ ccl.net Subject: CCL:[Beowulf] Opteron or Nocona ? (fwd from m.somers _(a)_ chem.leidenuniv.nl) (fwd from lindahl _(a)_ pathscale.com) ----- Forwarded message from Greg Lindahl ----- From: Greg Lindahl Date: Tue, 10 May 2005 00:03:11 -0700 To: Beowulf _(a)_ beowulf.org Cc: Subject: Re: [Beowulf] CCL:Opteron or Nocona ? (fwd from m.somers _(a)_ chem.leidenuniv.nl) User-Agent: Mutt/1.4.1i On Mon, May 09, 2005 at 08:05:28PM -0400, Mark Hahn wrote: > I would very much like to see a good comparison of Intel compilers > versus the alternatives. I know good things about Pathscale, for instance, > and gcc 4.0 and 4.1 seem pretty impressive. In addition to the usual benchmarks like SPECfp and Polyhedron, there is a computational chemistry comparison done by Daresbury Labs in the UK. Opteron+PathScale does quite well. http://www.polyhedron.co.uk/compare/linux/f77bench_AMD.html http://www.polyhedron.co.uk/compare/linux/f90bench_AMD.html http://www.cse.clrc.ac.uk/disco/index.shtml, especially http://www.cse.clrc.ac.uk/disco/Benchmarks/IntelProj.Serial.update1.pdf We're looking forward to Daresbury testing with our newest compilers, as we've made some substantial performance improvements since the version they used (1.2). -- greg _______________________________________________ Beowulf mailing list, Beowulf _(a)_ beowulf.org To change your subscription (digest mode or unsubscribe) visit http://www.beowulf.org/mailman/listinfo/beowulf ----- End forwarded message ----- -- Eugen* Leitl leitl ______________________________________________________________ ICBM: 48.07078, 11.61144 http://www.leitl.org 8B29F6BE: 099D 78BA 2FD3 B014 B08A 7779 75B0 2443 8B29 F6BE http://moleculardevices.org http://nanomachines.net -= This is automatically added to each message by the mailing script =- To send e-mail to subscribers of CCL put the string CCL: on your Subject: line and send your message to: CHEMISTRY _(a)_ ccl.net Send your subscription/unsubscription requests to: CHEMISTRY-REQUEST _(a)_ ccl.net HOME Page: http://www.ccl.net | Jobs Page: http://www.ccl.net/jobs If your is mail bouncing from ccl.net domain due to spam filters, please use the Web based form from CCL Home Page -+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ ================================================================================== > From konstantin_kudin _(a)_ yahoo.com Tue May 17 00:06:00 2005 Date: Mon, 09 May 2005 19:01:04 -0700 (PDT) From: Konstantin Kudin To: mark somers , Luigi Cavallo Cc: chemistry _(a)_ ccl.net Subject: CCL:Opteron or Nocona ? Actually, highly optimizing compilers for Opteron do exist (such as Pathscale). Even Intel Fortran 8.1 (either 32 or 64 bits) produces decent code for Opteron since Opteron is not as fragile as Pentium 4 in terms of which code it likes and which it does not. There is one specific situation where Nocona could come as a clear winner, but such cases are not too common. Basically, codes that run BLAS routines such as DGEMM for the majority of their runtime gain a lot on Nocona when the correct libraries are used. This is because both Opteron and Nocona run BLAS proportionally to the clock speed, so the much higher clocked Nocona wins (~3 vs ~2 Ghz). On the other hand, multi-processor Noconas can choke because of limited memory bandwidth, whereas Opterons under such circumstances do just fine. Last, here are some last year's Gaussian03 benchmarks, where both Opterons and Noconas were comparable: http://www.princeton.edu/~kkudin/g03_b5_tests_1.txt YMMV ... Kostya ================================================================================== > From gustavo.seabra _(a)_ gmail.com Tue May 17 00:06:07 2005 Date: Wed, 11 May 2005 14:31:06 -0500 From: Gustavo Seabra To: chemistry _(a)_ ccl.net Subject: CCL:Opteron or Nocona ? [ The following text is in the "ISO-8859-1" character set. ] [ Your display is set for the "US-ASCII" character set. ] [ Some characters may be displayed incorrectly. ] Notice that AMD has recently launched the Dual Core Opteron processors. There you can basically get the equivalent of twice as much processors, for about the same price. Check: http://www.infoworld.com/infoworld/article/05/04/21/17TCamd_1.html http://www.d-silence.com/story.php?headline_id=21036&comment=1 -- --------------------------------------------------------------------------------------------- Gustavo Seabra Graduate Student Chemistry Dept. Kansas State University Registered Linux user number 381680 Say NO! to software patents: http://www.nosoftwarepatents.com --------------------------------------------------------------------------------------------- ================================================================================== > From eugen _(a)_ leitl.org Tue May 17 00:06:15 2005 Date: Thu, 12 May 2005 10:41:00 +0200 From: Eugen Leitl To: chemistry _(a)_ ccl.net Subject: CCL:[Beowulf] Opteron or Nocona ? (fwd from m.somers _(a)_ chem.leidenuniv.nl) (fwd from kus _(a)_ free.net) Sorry for big delay w/answer: today is 1st working day after May's holidays here in Russia ;-) I've no doubts that in average Opteron is today better, in particular for computational chemistry codes. The reasons is both performance (for "top frequency" chips) and price/performance ratio. We stop to use Intel x86 for computational chemistry and began to use AMD from "Athlon times" - because of price/performance reason. But now Opteron is in average absolutely better due to a) single CPU performance (See, for example, SPECfp2000 which includes also some molecular dynamics codes) b) power dissipation (which is lower for AMD) c) dual (and higher also:-)) CPU system architecture: 2 Opteron's have 2 independed pathes to main memory instead of common system bus in the case of Nocona. As a result, Opteron's have much more good memory throughput scalability. Pls take into account that many modern quantum chemistry codes (like G03) are "restricted" by memory throughput ! What is about compilers, it was answered in a set of previous messages here. IMHO, the only HPC area where Nocona has clear advantage over Opteron, is floating point applications reaching performance close to peak value (like Linpack). In that case it should be take into account that Peak_Performance = 2*frequency for both processors, and Nocona has therefore higher values. But it's not typically for computational chemistry. Yours Mikhail Kuzminsky Zelinsky Institute of Organic Chemistry Moscow ==================================================================================