new Rig for 4-8 GPU Setup - X79 or P6T7 ?

[asterix7]

I am looking for a 4 GPU - 8GPU setup. Ideally I want to do Architectural Walkthroughs (interiors). I understand that performance might not be good enough, but I would like to test with simplifying environment/textures and light in order to get close to near real time - something around or less than 1 frame / sec.

basically I am thinking of using 4 x GTX590, or eventually 8x GTX580 3GB if I need the 3Gb memory per GPU.

For this I can choose between following motherboard/CPU combination

1) X58 board with i7 CPU. lowest cost - and some Motherboards have up to 7 - 16x PCIe 2.0 slots.
2) X79 board with later 3900K processor (not the 3900X - that one costs 1000 Eur) - this new design has 40 (!) PCIe lanes going straight into the CPU without needed any PCIe Chip (NF200 ?) with 4 PCIe 3.0 slots (but double width slots so can put 4xGTX590)
3) a 2 CPU board using Xeon 5620/5650 processors, having 16 (!) PCIe 2.0 single spaced, with PSU of 2400W up to 3600W.

What would give me
a) the best performance
b) what would give me the best "bang for the buck"

Is it feasable to put 4xGTX590 next to each other - or does this require watercooling ?

All this comes down to how much memory is usually moved around to the GPU cards ? I hear that the physical 16x slots would have more than enough perfo with a 4x bandwidth for moving data around. Do I need a top of the line CPU to feed the 8 GPU's or is a 'regular' i5 or i7 on X58/P6T7 fast enough and thus can have bigger budget for hte GPU's ?

I am going to benchmark the X79 board tomorrow (1xGTX590 and 2x GTX580), so any suggestions for benchmark files welcome.

[t_3]

I am looking for a 4 GPU - 8GPU setup. Ideally I want to do Architectural Walkthroughs (interiors). I understand that performance might not be good enough, but I would like to test with simplifying environment/textures and light in order to get close to near real time - something around or less than 1 frame / sec.

basically I am thinking of using 4 x GTX590, or eventually 8x GTX580 3GB if I need the 3Gb memory per GPU.

For this I can choose between following motherboard/CPU combination

1) X58 board with i7 CPU. lowest cost - and some Motherboards have up to 7 - 16x PCIe 2.0 slots.
2) X79 board with later 3900K processor (not the 3900X - that one costs 1000 Eur) - this new design has 40 (!) PCIe lanes going straight into the CPU without needed any PCIe Chip (NF200 ?) with 4 PCIe 3.0 slots (but double width slots so can put 4xGTX590)
3) a 2 CPU board using Xeon 5620/5650 processors, having 16 (!) PCIe 2.0 single spaced, with PSU of 2400W up to 3600W.

What would give me
a) the best performance
b) what would give me the best "bang for the buck"

Is it feasable to put 4xGTX590 next to each other - or does this require watercooling ?

All this comes down to how much memory is usually moved around to the GPU cards ? I hear that the physical 16x slots would have more than enough perfo with a 4x bandwidth for moving data around. Do I need a top of the line CPU to feed the 8 GPU's or is a 'regular' i5 or i7 on X58/P6T7 fast enough and thus can have bigger budget for hte GPU's ?

I am going to benchmark the X79 board tomorrow (1xGTX590 and 2x GTX580), so any suggestions for benchmark files welcome.

my opinion: bftb - if you don't need cpu horsepower for other things, x58/2600k is the best. octane needs the cpu only for preparing/voxelising, and as this is a single threaded process right now (don't know if this is subject to change), a 2600k at 4.x ghz (if you dare to oc), will be even better than the new i7 3x cpus. the sandybridge cpus also have the advantage of the integrated gpu with virtu switching between dedicated and integrated cpu, what may help to free up all nvidia gpu resources for rendering (if it works ;)

also octane is moving lots of data only once over pcie to the gpu (also while preparing), so x1, x4 or x16 won't make a big difference imo...

[gabrielefx]

this is my config:

http://www.refractivesoftware.com/forum ... 40&t=10042

5.150,00€


for 8 GPU you need a Tyan barebone:

http://www.tyan.com/solutions/gpu_platforms.aspx

10.500€

[asterix7]

gabrielefx: yep, the 2CPU option in 3 is a Tyan 4U rack I found. rack itself costs 2550 GBP. You need to add cost of GPU's, CPU's and mem. 2xPSU, MBrd and case with vent are already included. So what I am saying is that I estimate price of the fully configured Tyan around 4000 Eur plus cost of GPU's. Putting 8 GTX580's will be interesting on heating though, as some seem to say you need watercooling if you put them next to each other without space

[asterix7]

Nice rig though - did u built it yourself or got someone to assemble it ? Where did you find the Termin case ? Saw the youTube on the new coming 12 case.
Are you in Europe somewhere ? Good to heaqr the GTX580 will stand 4 next to eachother. Have the eVGA GTX590 Classified, and am awaiting my benchmarks, to add GTX580 3Gb eVGA Classified (when it gets into stock)

[t_3]

Nice rig though - did u built it yourself or got someone to assemble it ? Where did you find the Termin case ? Saw the youTube on the new coming 12 case.
Are you in Europe somewhere ? Good to heaqr the GTX580 will stand 4 next to eachother. Have the eVGA GTX590 Classified, and am awaiting my benchmarks, to add GTX580 3Gb eVGA Classified (when it gets into stock)

don't know if anyone has a working 590 stack on air (having the cards with no space beneath each other), but i don't think it'll work well - because the fan is on the side instead on the bottom of the card...