A Z77 chipset for 3 GPU rendering

[portnicki]

Is this a smart idea?

I mean a Z77 chipset has a limitation for PCI-E lanes speed working at the same time.
If I put 3 cards to the motherboard, two of them will work at x8 speeds and one with x4.

Does this limit rendering speed by any means?

I already have a Titan card and GTX460. I plan to hook up the monitor to the GTX460 and leave it out of rendering (use it only for Windows GUI), and use a Titan and maybe an additional GTX580 for rendering.

Won't the Z77 board limit my rendering performance?

[glimpse]

hi there.

Z77 isn't bad at all =) out of the box majority of cards will have at least one PCIe (gen3) cappable delivering x16 electrical link. If boards layout is in favour (have two conections) then those would work at x8. Third card ussually gets x4 (gen2) electrical link.

now procesor hooked on this this socket (1155), smth like 3570, 3770 etc. is capable delivering only 16lanes, unlike 2011 that has 40 =) however there'a a workaround that is caled PLX chip. if You find a board with it (8747) seated in Z77 based mobo, You'll be able to run four x8 (electrical) conections & that would allow You to have four dual slot cards (if layout allows).

Basicallty all the vendors have at least a model with this chip (Gigabyte G1.Sniper 3, Asus Maximus V Extreme, Z77 Extreme9, etc). Because of increased cost these will ussualy have a price tag of 200-300$ (or even higher if there's more additional features onboard) compared to ~120$ for a regular mobo without PLX =)


Now Your question about rendering speed. You can plug card in x4 or x1 if You wish, the rendering performance will be the same (as all of these calculations is happening inside the card), but..loading of the scene will be longer the slower connection You have. Some in this forum would say it's nothing bad..however it depends what is the purpose of Your system.

If You are building a daily monster that You'll spend lots of time I'd get GPUs plugged at x8, 'cos it just makes no sence to spend thousands for GPUs and save hundred $ for a mobo.. - it's like having scientist brain & two left legs.. - maybe it's good in a laboratory, but not on a dance flor..or even out in the city =) I'd go for balanced system just to be sure I have as little bottlenecks as possible..- who like to work with old crappy HDD when we have SSD's 10x faster?

that's it, Portnicki
hope it helped a bit

[portnicki]

oh wow glimpse, you've helped tremendously!
this is more than I could ask for!

The thing with my system is I have only one PCI-E slot right now with a Titan card.
I know it's much more comfortable to work with a second card that's handling only the GUI, not rendering.

I also already have an old processor - 2600k. I don't feel like changing it. So i figured I would only swap the mobo for something that has more PCI-E slots and will fit my processor.
I can get a used (with warranty) MSI Z77A-G45, which has 3 PCI-E slots. I figured I would use a GTX460 as a primary card for Windows and the Titan and one GTX580 for rendering.

I don't really need very fast scene loading, I care more for fast operation on the scene once it's loaded.

Is this a good idea or should I replace the mobo and the processor istead?

Thanks again for taking the time to answer this post glimpse!

[glimpse]

I also already have an old processor - 2600k. I don't feel like changing it. So i figured I would only swap the mobo for something that has more PCI-E slots and will fit my processor.
I can get a used (with warranty) MSI Z77A-G45, which has 3 PCI-E slots. I figured I would use a GTX460 as a primary card for Windows and the Titan and one GTX580 for rendering.

I don't really need very fast scene loading, I care more for fast operation on the scene once it's loaded.

Is this a good idea or should I replace the mobo and the processor istead?

Thanks again for taking the time to answer this post glimpse!

2600k is a nice CPU, all the succesors brough only like 10-15% of speed improvement with every new generation - so it still stands high in terms of performance. If You wan't to save some money & have a reasonable upgrade, look for a mobo and swap it for some time =) as I've mentioned there's nothing bad running card on 4x it will not give any penalty on GPU rendering performance. Just laoding time. P.S,. 2600k (if I'm right) should be compatable with z77, but does not provide PCIe gen3. In theory Gen3 is twice as fast as Gen2, however in reality it's hard to notice the difference..especially if You're workin' with simple scenes (don't really know how that touches games as I don't game at all).

So, to sum up, there's nothing bad to stick with 2600k & compatible mobo for a while. On the long Run I'd start thinkin' for some basic dual core, if You don't need CPU power (like that aniversary edition, that comes for mare 80$) & some better mobo ~200$ (with PCIe switches to turn of lanes, without the need of disassembling system if You have some problems), + some ram..- for some process You migh need it =) that system would work producing less heat, performance would be better in some cases, but..-that comes with cost & even this budget build based on new system would probably be around 500$ (CPU, MOBO, RAM) os getting a mobo replacement in Your case would be the fastest more affortable move, I've just tried to give You an idea of some limitations & options =)