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Re: again...hardware for octane
Posted: Tue Jun 01, 2010 5:54 pm
by koots
If I were to buy a
EVGA 012-P3-1470-AR GeForce GTX 470 (Fermi) 1280MB 320-bit GDDR5 PCI Express 2.0 x16 HDCP Ready SLI Support Video Card
http://www.newegg.com/Product/Product.a ... -_-Product
Would this be a good option? I could spend about $365 and that is about it.
Re: again...hardware for octane
Posted: Tue Jun 01, 2010 6:03 pm
by Amplitude
of course it is a good option. it is one of the best card for octane and evga is a very good brand.
Re: again...hardware for octane
Posted: Tue Jun 01, 2010 8:16 pm
by havensole
Yup. I have that EVGA gtx470 and an MSI gtx470. The EVGA seems a little smoother then the MSI. Most likely because the MSI has an older bios on the card. Try looking at tiger direct as they were a little cheaper (and came with a free t-shirt
).
Re: again...hardware for octane
Posted: Wed Jun 02, 2010 5:10 am
by CGicore
havensole wrote:Nope. 2x gtx260's will only give you 432 cores. That is less then 1 gtx470. If you are really strapped, check out the new gtx465. It has 352 cores and goes for just under $300 USD. It only has 1gb of ram though. Also you don't want to use SLI, it just screws everything up. If you use multiple gpu's you leave them disconnected from each other and just let the software combine their power. Make sure to buy stock, non-overclocked gpus as OC'd cards can give problems with Octane. That will also save you a few bucks.
I c what you mean, thanks m8.
Re: again...hardware for octane
Posted: Wed Jun 02, 2010 8:22 am
by Amplitude
havensole wrote: Make sure to buy stock, non-overclocked gpus as OC'd cards can give problems with Octane.
Hey havensole,
can you tell me more about that? what kind of problems?
Re: again...hardware for octane
Posted: Wed Jun 02, 2010 7:19 pm
by havensole
Reports have been all over the place from system shutdowns, weird artifacts appearing on the screen (even with Octane shutdown), Octane crashing, dead gpu. Basically just bad stuff. Even some stock cards might run into issues, though very rare. EVGA's precision, or the stock nvidia control panel, can be used to underclock the gpu a little to get it stable. If your scene is fairly small and can be rendered pretty quickly, like under a minute, it might be fine. Emphasis on might. The big issue is cooling. The cooling systems on these cards are not designed to run at full blast for long periods of time, and OC'ing them produces more heat, hence the issues. There are probably some other reasons for the OC'ing issues (multipliers and such) but it is just a safe bet to just buy stock gpu's or underclock an existing OC'ed gpu.
Re: again...hardware for octane
Posted: Wed Jun 02, 2010 7:36 pm
by Amplitude
all right, thanks for the info.
Instabilities and burned chips... it does sound like overclocking pushed way too far.
Normally serious overclocking is validated by running extensive burn-in tests that are supposed to load the gpu way more than a real application. But you're right, better be safe than sorry.
Re: again...hardware for octane
Posted: Wed Jun 02, 2010 10:45 pm
by havensole
Especially when you are talking about a gpu costing a couple hundred dollars in the case of the new gtx400's. Performance increases would not be huge, so what's the point in risking costly hardware.
Re: again...hardware for octane
Posted: Thu Jun 03, 2010 10:55 am
by Florinmocanu
I wrote here some info about processing power (rendering/computing) of different GPUs from nvidia or ati.
http://www.refractivesoftware.com/forum ... 340#p20340
First thing, computing/rendering power of a video card counts on double precision power, that is the important stat we need to look at when considering a GPU.
GF100 chips (fermi) have around 1.1-1.2 Teraflops single precision and for 2 single precision operations they can do 1 double precision operation, so around 600-550 Gflops of DP power.
A G80/G92/ GT200 based card, for each 8 single precision operations can do 1 double precision operation. A GT 200 (GTX 285) has around 0.8-0.9 teraflops SP and i think around 90-100 Gflops of DP.
But, Geforce versions of fermi are neutered, the have only 164 Gflops double precision compared to some 500 Gflops of quadro/tesla cards based on fermi (which should have been the real power of normal Geforce as well). It was a decision made because of 2 reasons.
1. increase sales of quadro/tesla, because people would buy them for extra rendering/compute power + extra memory.
2. reduce power consumption on geforce products. Double precision doesn't count for gaming so they disabled some computing capabilities to minimize power consumption in order to be able to get decent clocks out of fermi chips without going over 300 w ( which is the limit PCI-E 2.0 standard limit).
Compared to 164 Gflops of a 480, a GTX 280/285 has around 80-90, so you can see why earlier products, G80/G92 and GT200 are still decent compared to Fermi.
I would personally advise, until DX 11 comes to Octane, to find a 2 GB GTX 285. I think it's the best combo of speed/memory available right now on the market. Well, until we see 3GB GTX 480, if the manufacturers will make such a design in the future.
Edit: Another thing, about ATI cards. And why i wish Open CL/Direct compute can find a place in octane in the future.
Ati cards are not neutered in any way, since they don't have tight power limitations, their around 180-190W for a 5870, so well inside the 300W limitation. A 5870 has 2.7 Teraflops single precision and 1/5 DP power, so around 540 Gflops DP. If Octane could use Ati cards, ati cards would rape everything. But, it seems AMD should involve a bit more into software development/support to promote computing on Ati cards.
I hope you find this useful.
Until DX11 comes to Octane, so v 2.0, i would recomend a 2GB GTX 285 for rendering since it has the highest ram for a single Nvidia GPU out there. Ram i think is the biggest limitation right now for GPU rendering.
Re: again...hardware for octane
Posted: Thu Jun 03, 2010 5:42 pm
by havensole
It will be more OpenCL coming to Octane, not DX11. OpenCL is still in early development, but with the increased desire for it for rendering purposes I can see its development growing faster. When we will see this come to Octane is up in the air, and whether or not ATI will be better is anyone's guess. It is not just how many gflops a processor has, but how the software can utilize them. Memory management is a big thing when looking at gpgpu applications and some do it well, and others do not. We will see. I am optimistic even though this might not sound that way.