How important is VRAM for gaming?

[doctorwho62]

Hi, thanks for taking the time to help me

So I'm building a new gaming rig, and I was easily able to choose most of my components, but I hit a snag when it came to deciding
what graphics card to choose. After many days and innumerable hours searching the internet for usefull input I have narrowed it down to a choice of two:

2GB Nvidia GeForce GTX 660 Ti
3GB AMD Radeon HD7950

Now I did my research on these cards and found that the general concensus was that they were about equal, the GTX having PhysX and better
driver support; and the HD having an extra gig of VRAM and more potential for overclocking.

In the end it came down to one difficult decision; do I want the Nvidia with its ability to run PhysX (note 1), and it's reputation
as being better supported; or do I want the AMD for its extra gig of VRAM and overclocking potential (I do intend to OC the graphics card when I get it).

tl;dr/My Question is this: Is it worth the extra 1GB of VRAM and OC'ing potential to get the HD7950, sacrificing driver support and PhysX; or would my best bet
be to go with the GTX 660ti?

Note 1: I know not a lot of games run PhysX right now but there is something about the idea of buying an expensive
peice of hardware and still missing out on something that puts me off.


Finally I'd like to give you a little more information:
1.There is a possibility that I will go SLI/Crossfire in the future, if I can get enough money before the chosen card becomes obsolete/inadequate.
2.Both cards will cost me roughly the same so I don't care about the price differences.
3.My screen resolution will be 1920 x 1080, single screen.
4.I intend to go on the highest graphical settings possible on games like Crysis, Skyrim, BF3, and Metro 2033, all the usual benchmarks.
5.Any other information or recommendations you want to give would be very appreciated, as this is my first custom rig and I'm Very inexperienced.

My propsed rig:
CPU: i7-3770K Quad Core (OC'ed to about 4.6GHz)
MOBO: Asus P8Z77-V
RAM: 16GB Kingston HyperX Genesis Dual-DDR3 2133MHz (4 x 4 sticks)
GPU: Nvidia GeForce GTX 660-Ti OR AMD Radeon HD7950
Memory: 240GB Kingston HyperX 3K SSD
PSU: Corsair 650W Enthusiast Series
Thermal Paste Arctic MX-4 Extreme
Sound Card: Asus Xonar DGX 5.1
OS: Windows 8 Pro 64 bit

If you've read this far then thanks again for your time. I'll be happy to try and answer any questions if it helps.
P.S. Sorry if this has been answered before but I searched the forums for a few hours and couldn't find my answer.

 

[clutchc]

With a single 1080p display, 3GB will be wasted. The extra VRAM is mainly for higher resolutions, as in multiple monitors. Although, some demanding games require more than 1GB VRAM to utilize all the eye candy. If you plan on adding monitors, go for the 3GB. Otherwise 2GB is great. Most games are fine with 1GB.

Other than VRAM, the two cards are pretty well matched: http://www.hwcompare.com/13145/geforce-gtx-660-ti-vs-radeon-hd-7950/
... on paper anyway.

You may want to consider a more robust PSU for SLI/Xfire with either of those two cards. 750W or better is a good starting point. And I believe the PSU you chose only has enough PCIe power cables for 1 of those cards anyway. (A give-away that it isn't expected to be used at that level)

 

[jaguarskx]

The resolution you intend to play games at will dictate how much you really need. Up to 1920x1200 resolution all you really need is 1GB. Yeah, yeah I'm sure someone will chime in stating that Crysis 1 sucked balls when playing at 1920x1200 with just 1GB of RAM on the graphic card. The truth is Crysis had a memory leak problem. That's an issue with how the game was coded, not with the graphic card.

Up to 2560x1600 2GB should be fine. If you plan on playing games with 3 monitors, then 4GB would be recommended. Of course the graphic card(s) needs to be powerful enough to play games at really high resolution.

 

[doctorwho62]

Thanks a lot for your answers guys, they really helped.

Like most, I assumed more equals better, but now that I know what VRAM is
actually needed for I can make a better informed decision, 660 Ti it is!

Thanks again for your help guys.