[Shopping] Graphic card

[cyprine]

helloz Octanites !

xmas is getting close & i think i'll santa my machine an additional graphic card - i crave computing power

i've got an alienware aurora r4 - nice machine that comes with its caveat: there is very little room for customization since each bolt & plug is proprietary.
its running a geforce 680 & i'm looking for advice to find a suitable companion.

i will get (daz)Octane 2.0 when its out (soon !) & with all the obscure tech thingies my noobyness cannot fathom, i was wondering:
the 680 is kepler architecture: can i pair it with maxwell (700+ series)?
the 680 has 2Go vram: if i get a second card with more memory, am i still stuck with the 2Go or does octane 2.0 remedies that ?

i dont play the lottery so... no titan black zz plural alpha for me.

thanks in advance for your suggestion (and patience with my ignorance of things tech).

[SimonJM]

If you use both cards for the rendering you will be limited to the smallest amount of VRAM in them as all the cards involved need to hold their own copy of the scene data. You could, however, assign the card with the smaller amount of VRAM to be the one that drives the GUI and the other to be the one that does the actual rendering.

[sikotik13]

In addition, the only 700 series card that runs on Maxwell architecture is the 750, all other 700 series run Kepler. The new 900 series is all Maxwell based, as well. If it were me, having just purchased two solely for this purpose, I'd get a GTX 780 6gb. Plenty of overhead, and the cheapest way to get 6 gb of Vram, also pretty speedy at a reasonable cost, comparatively. Oh, and I agree, I would just run the 680 for display (uncheck it in the system tab, so it only uses the other card, the 780 in my example, for rendering). Just my two cents. Plus, if they have them in stock on black friday, you could probably snag one for about (or even less than) $500. Well worth it, in my opinion.

[cyprine]

ty for your input.
now, say i get a 780 as suggested by sikotik13:
- assigning the 680 to gui, how much computing power do i gain ? is it only comfort (being able to do something else while rendering ?) or do the 680 still lends some cores to computing the render ?
- having the 680 & the 780 work together on rendering (i understand the memory limit), do i gain computing power (render time) ?

path traced dim lit scenes takes far to long at the moment for the projects i have in mind & i really want to cut the render times: i'm still learning so a bit of time is somewhere in efficiently setting my scenes & textures but definitly my hardware needs a bump

[sikotik13]

The 780 has more cores, so would process the same data faster. Using them together would be faster than that, at the cost of (likely) a nearly unresponsive display (should you realize you need to do anything else, you would pretty much have to pause the render to have a functional computer). If you are one of the type who make sure everything is perfect before rendering, you could use them together for a (likely) moderate speed boost, but moving rendering from the 680 to the 780 will likely be worthy of consideration. There's nothing stopping you from going back and forth, depending on your needs. Just a check in a box. Cooling may be a factor to consider as well, as I am unfamiliar with your case and/or any cooling you have running. One card gets warm, two may get hot, just depends on a number of variables, and if that is the case, running the one 780 may be a better trade-off for temps, since if the card(s) get too hot, they will pause the render to cool anyway. It's all pretty flexible though. Hope some of the mass of text is helpful

[glimpse]

depends from model to model as there are differently specced cards (factory preOverClocked), but 780 is about twice as fast 680..(for the sake of simplicity)..So if You not against being limited by lower amount of vram on 680 (let's say working on the scene that fits into 4gb), then Your render times should get to 30-40% of what You were used to.. if You take 680 out & render on 780 only, then You should get the same result in about half time required while rendering on 680 =)

p.s. for some light workload I'd use inbuilt GPU (iGPUs) on CPUs/APUs just to handle interface..-wasting entire discrete GPU for screen (unless You really need it - let's say iGPU can't handle Your workloads) is not so wise in my eyes.

[cyprine]

thanks again for the illuminating answers, specialy in a language i can understand

for some light workload I'd use inbuilt GPU (iGPUs) on CPUs/APUs just to handle interface..-wasting entire discrete GPU for screen (unless You really need it - let's say iGPU can't handle Your workloads) is not so wise in my eyes.

now you lost me here - you suggest to use the inbuild gpu while rendering: can you tell me how to do that ? (using windows 7 if that helps)

[sikotik13]

He is saying that if your processor (or most motherboards, now that I think of it), has it's own video handling capabilities, to use those instead of a whole graphics card for display (monitor). It's a better use of available resources, if that's an option. I am unfamiliar with iCPUs, but I presume they are the Intel equivalent to the AMUs from AMD, which just means the processor was designed to also handle video output in the absence of a video card, or to lighten the load on a video card. As I mentioned upon reflection, a motherboard with it's own graphics out could probably achieve the same results, but might require you to configure the BIOS to read both. That's a much broader area, but worth a look to get the most bang for your buck.

Also, thank you glimpse, I tend to forget to make things readable. Too used to gaming/overclocking forums *hangs head in shame*

[Spectralis]

I think the 780 6GB is the best suggestion. Either that or wait for the 8GB version of the 980. I've read though that the 980 isn't performing that much better than some of the top end cards in the 7xx range. Some say this is a driver problem but I'm not sure whether this is still the case.