<br><br><div class="gmail_quote">On Thu, Mar 27, 2008 at 9:41 PM, Ricardo Reis <<a href="mailto:rreis@aero.ist.utl.pt">rreis@aero.ist.utl.pt</a>> wrote:<br><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">
<br>
Hi all<br>
<br>
I beg to take advantage of your experience although the topic isn't<br>
completly cluster thing. I got some money to buy a new machine, at least<br>
8Gb and I'm thinking between a 2 x dual core or a 1 x quad (or even 2x<br>
quads). It must be one machine because it must (urgh) be able to use it's<br>
8Gb in serial codes (don't ask).</blockquote><div><br>Just be aware that most of the machines designed to be number crunchers<br>have shortcomings in board layout or bus design that make them suck for<br>visualization.<br>
<br>Not that many that will be happy with 8GB for starters. So few machines are<br>actually ever populated with big dimms that you almost always get issues.<br>So you end up going for machines with lots of ram slots, ecc support etc, which<br>
is all good. These are almost always at least dual socket. But many of those<br>motherboards aren't designed to take a 16x PCIe graphics card and only have<br>PCIe 8x buses. Also, graphics cards have an extra retaining lug which<br>
extends further than the PCIe slot; this is commonly blocked on server<br>motherboards by some capacitor.<br><br>High end graphics cards always take up two slots and require additional power; on<br>the Quadro 5600 and other cards this connector enters from the top not the end,<br>
hence making it impossible to fit them in a 3U case. Oh yeah -- don't think about<br>one of these for under your desk unless you want to wear earmuffs in the office.<br> </div><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">
Anyway, I've been experiencing with<br>
paraview for parallel visualization and was wondering on your opinion<br>
on... buying a ultra-duper-cool state-of-the-art graphic card (Nvidia) or<br>
2 graphic cards?</blockquote><div><br>Depends -- is performance critical *now*? If so, buy the fastest Quadro. If you want<br>to maximize performance over time, just upgrade the graphics card every six months<br>with the sweet spot on the price/performance curve. Quadros are the first low-yield<br>
parts from the fab; the same chips, with slightly slower/cheaper memory hierarchy,<br>become mass market later.<br><br>Don't bother with SLI, you won't notice any speedup unless you invest lots of tuning<br>time. And since your viz app is 3rd party, probably no speedup at all.<br>
<br>ATI vs nVidia: ATI drivers really really suck. nVidia drivers are generally stable unless<br>you are on the bleeding edge (eg brand new part) or a corner case (eg quad buffered<br>stereo on a 2.2 kernel but with recent hardware & drivers). nVidia developer support<br>
sucks too unless you are a major game author or eg industrial light & magic. ATI<br>developer support is non-existent under linux; under windows I'm told they can be ok<br>about fixing windows bugs.<br><br>Regards,<br>
Andrew<br>(flight simulation geek)<br><br></div><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;"><br>
<br>
thanks for your time,<br>
<br>
Ricardo Reis<br>
<br>
'Non Serviam'<br>
<br>
PhD student @ Lasef<br>
Computational Fluid Dynamics, High Performance Computing, Turbulence<br>
<a href="http://www.lasef.ist.utl.pt" target="_blank">http://www.lasef.ist.utl.pt</a><br>
<br>
&<br>
<br>
Cultural Instigator @ Rádio Zero<br>
<a href="http://www.radiozero.pt" target="_blank">http://www.radiozero.pt</a><br>
<br>
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