GPU question for vray-rt

[mahmoud_s12]

I am building my new system and I am thinking of buying 2 GPUs

Galaxy GeForce GTX 680 GC 4GB GDDR5

ASUS GeForce GTX 650 DirectCU 1GB GDDR5

 

Is it a good idea to buy these 2 cards and will they work together properly and use SLI?

will I be able to use one for vray-rt GPU render and one for the viewport?

 

is this the best choice or can i get a better choice for the same price range??

 

These 2 gpus will cost me about $770

 

I am also thinking about adding another GTX680 in the future

[Dimitris Tolios]

SLI is not used by VRay RT. Each card works independently and doesn't have to be tethered with another or be identical.

You are probably wasting your money on the 650, as for the really complex scenes it won't be contributing much, or won't be working at all being limited in VRam.

 

SLI = two or more cards rendering every other frame or other line etc spreading the load. This is possible only with identical cards, and only supported by games atm.

 

If I were you, I would get a 4GB 670 GTX to try out VRay RT before investing all that money. In the US those cards are around $400-410 (there are offers for the holidays). You will be spending nearly half what you think investing now, and if you really like it, you can add a second one later.

 

4xx/5xx/6xx Geforce cards don't have great variation in viewport performance. If you are working with scenes that REALLY need a faster GPU cause viewports are laggy, you would have to go mid-range Quadro or FirePro.

[mahmoud_s12]

SLI is not used by VRay RT. Each card works independently and doesn't have to be tethered with another or be identical.

You are probably wasting your money on the 650, as for the really complex scenes it won't be contributing much, or won't be working at all being limited in VRam.

 

SLI = two or more cards rendering every other frame or other line etc spreading the load. This is possible only with identical cards, and only supported by games atm.

 

If I were you, I would get a 4GB 670 GTX to try out VRay RT before investing all that money. In the US those cards are around $400-410 (there are offers for the holidays). You will be spending nearly half what you think investing now, and if you really like it, you can add a second one later.

 

4xx/5xx/6xx Geforce cards don't have great variation in viewport performance. If you are working with scenes that REALLY need a faster GPU cause viewports are laggy, you would have to go mid-range Quadro or FirePro.

 

Thanks Dimitris

in Egypt there's only the 2GB version of GTX 670

so if I can't find GTX 670 4GB... I'll have to get only one GTX 680 4 GB... right?

 

another question: what's the differnce between Galaxy GeForce GTX 680 GC 4GB GDDR5 and EVGA GeForce GTX 680 Classified 4GB GDDR5 ?

[Dimitris Tolios]

None real difference.

Both are top of the line GTX 680 GPUs, with the base clock of the cores raised (factory overclocked) from 1006MHz to ~ 1110MHz...

I would not bother with either. The "Classified" was initially meant to be a fully overclock-able card with an external device that would by-pass the over-volting protection nVidia has applied on all Kepler cards, but nVidia threatened to stop providing factory warranty for those cards and EVGA abandoned the project. Classifieds cannot do anything more than any other 680 already can tbh.

 

Personally I have an EVGA 670 SC 4GB, simply because I could not find any other 4GB 670 at its price back in July.

I can clock the card @ 1100+ without extra Volts (that is locked anyways).

I am happy with the card, but the fan is a bit noisy, so if I had the choice I would opt for an "open-fan" design, like that on the Galaxy, MSI or Gigabyte cards that cools just as good - if not better - but noticeably quieter.

 

Note: during 3DS Max and Sketchup modelling, the card is virtually idling, thus running VERY cool and is nearly silent (you can tweak the fan RPM curve to make it spin up as high as you want at certain Temps). As I've wrote above, the last few generations of GTX cards are intentionally under-performing, only with games and while GPU rendering you will see it actually working.

[mahmoud_s12]

Thanks...so I'll go for the galaxy GTX680 as it's $60 cheaper than the EVGA