Explanation on various GPU elements, their usage

[Koween]

Hi. I'm getting ready to upgrade my GPU, but for that I want to expand my knowledge about them slightly. I've been reading thread after thread on all of this 2gb vs 3gb/4gb debate.
What I want to know if whether there is a guide, an explanation of some kind, what aspect of a PC game taxes the GPU core and what fills up the vRAM. I know, that higher resolutions and high-res textures use more vRAM, and all kinds of effects etc put more strain on the GPU itself. But the big question is if it's possible to fill up more than 2Gb of vRAM with textures running a simple 1200p monitor and still have enough GPU horsepower to process all that data. The card in question is a 660TI 3Gb and, let's say, modded Skyrim or any other game, that can use up more than 2Gb of vRAM just with high-res textures.

 

[Forceman]

A 660 Ti, by itself, will not be limited by 2GB of VRAM because the card is not powerful enough to run settings high enough to need more than 2GB of VRAM. Even the GTX 680 does not suffer any issues with 2GB of VRAM when used alone (SLI might be different, depending on the game). That said, if you are going to get the 660 Ti, that 3GB card (assuming you mean theGalaxy one) is a pretty compelling card. Not so much because it has 3GB, but because it runs that memory in a balanced configuration unlike the stock 2GB cards which may improve performance (although it is yet to be proven), plus you get custom cooling and Galaxy support.

 

[Koween]

Yes, but don't high res textures, for instance, put most strain on vRAM and very little strain on GPU itself? As for 3gb vs 2gb - the 3gb model is about 25% more expensive than the 2gb model where I live, so I seriously doubt it's worth the miniscule performance increase. I wanted to go 3gb+2gb SLI, since only one card's vRAM is used, but now I think this cannot be done (last time I ran SLI was quite some time ago) and they have to be perfectly identical (please correct me if I'm wrong).

 

[IdiotInCharge]

Yes, but don't high res textures, for instance, put most strain on vRAM and very little strain on GPU itself? As for 3gb vs 2gb - the 3gb model is about 25% more expensive than the 2gb model where I live, so I seriously doubt it's worth the miniscule performance increase. I wanted to go 3gb+2gb SLI, since only one card's vRAM is used, but now I think this cannot be done (last time I ran SLI was quite some time ago) and they have to be perfectly identical (please correct me if I'm wrong).

For Nvidia they need to be real close, closer than AMD cards, but that's not a bad thing.

Further, when it's said that you only use the memory on one card, what they mean is that the data is mirrored- what's on one card is on all of them. You have the effective capacity of a single card no matter how many you have, and the capacity of the smallest card if you're on AMD.

And high-res textures will put a little strain on the card(s), but only if you choose to use them. Higher resolutions are your biggest concern.

 

[Koween]

Okay, thank you. Then a 3GB 660ti is pretty much a waste of money, as a little bit more would buy a gtx670.