> workstation (O2, Octane, Fuel, Onyx)? I've got an old Pentium III PC with 450 > MHz and a (non-stereo) Nvidia GeForce2 MX440 graphics card side-by-side with > an SGI O2 with a R12000 processor: a simple pymol (0.86) movie of a protein > sketch at 800x800 resolution and maximum display quality requires on the SGI > 3 minutes for 180 frames, i.e. 1 frame/sec, whereas the same movie requires > on the PC 20 seconds, i.e. 9 frames/sec. I wonder how this can be and would > like to hear about your experiences.
Short answer: unless you're doing some very special stuff, the PC is always the better deal. SGIs are good when you're buying something *big*- they get really interesting just past the limits of current PCs (e.g. Onyx300 and up). Long answer: The O2 does not have fast graphics. What it can do is deal with massive images/objects due to the weird unified memory architecture. This is great if you're doing (for instance) video editing, or stuff with lots of textures. For raw polygons, though, the NVidia card will blow it away, even though that's a relatively puny card by current standards. There are limitations to the PC architecture that can make it a pain in the ass to use after a while. For instance, I used to have a stock Micron machine with a GeForce2-something and a 1200Mhz Athlon. Interactive graphics were great- Unreal Tournament had no problems. As soon as I tried to render movies in PyMOL, though, the entire system ground to a halt. Switching to dual processors, tons more memory, and U160 SCSI fixed this, but I've never seen an SGI collapse that way. The O2 is not really a good comparison, however, because it is not designed primarily for modelling. An Octane would have a better chance, but only with faster graphics. I just tried the Octane2 next door (first time it's been available! yay!), which is a dual R14k-400 with V8 graphics. Interactive display of the small ribosomal subunit (with protein ribbons) was competitive with my Quadro4 900. If you're just talking about *rendering* in PyMOL, my experience was that a 600Mhz R14000 corresponds roughly to a 1200Mhz P4. (For some applications the speed difference is much less, but this is a good test for a single-processor app.) The only way to evaluate these differences, unfortunately, is to try all systems yourself. If you *really* have a lot of money to spend, sure, go for the SGI- after about $6000 there's not much more you can do with a single PC (unless you go for dual 23" lcds or something obscene like that). If you're on a budget, stick with a PC. By the way- a Quadro4 needs a very powerful computer behind it to make much of a difference. If you try to use on on your PIII, you will be disappointed. (This seems obvious, but was a bit of a shock to me when I found out the hard way.) ---------------------------------------------------------------------------- Nathaniel Echols Programmer n...@bioinfo.mbb.yale.edu Gerstein Lab 203-589-6765 Yale University ----------------------------------------------------------------------------
