Hi,
Really don't see the point of the 2.5gb 570 - unless you run a 30" monitor and are sure the extra vRam is what you need. If you like massive amounts of AA and simply must have super-sampling enabled then it might help. However I think the 1.25gb card is more than adequate for 1920x1080/1200, with 16xAF and 4xAA applied. Note: I have run some games (just to test it) with 16xAF, 32xAA and 8x Super Sampling. It takes an FPS hit of course, but it's not running out of vRam.
I remember after Crysis had come out I tried to run it at 2560x1600 on my 512mb 8800GT, it played surprisingly well. Ok, FPS was low but vRam wasn't the issue - running out of vRam would usually mean a proper slide-show, whereas Crysis played at low-fps for sure, but you could play it. This was with settings maxed, but no AA, just for the hell of it. Obviously Crysis needed a more powerful card, but my old 8800GT did its self proud!
My GTX 275 had 896mb vRam, yet that never exhibited the symptoms of running out of vRam either.
So yeah, a GTX 570 1.25gb is a great card, I'd not spend the extra for double the vRam unless I had a very good reason.
Oh, one more thing, one chap on another forum constantly posts how "anything less than 2gb vRam isnt enough" - he regularly states as "proof" the fact that Shogun 2 won't let you run the benchmark at high resolutions with high settings. He totally ignores that fact that the actual game will play just fine at these settings with less vRam, given a sufficiently powerful AMD/NV GPU of course.
Here's the thing. I think GPUs cache data. I.e. Playing Crysis 2 I might see 1.2gb of vRam used - "oh noez, I'm running out of vRam!" well, no. I can be using 1.2gb vRam, hit a checkpoint (save) quit the game, reload, do a 360 degree look around (so all texures and objects as before are loaded) yet now I'm showing 700mb vRam used...sorta proves that stuff was cached from prior scenes to me & swapped out as needed. I notice this in a lot of games, my vRam filling up the longer I play. This is a GOOD thing as the game is making the best use of what it has to potentially speed things up.
This is just how Windows 7 works - for example, this PC (my Q6600, now my gateway PC) is currently using over 6gb RAM just at the desktop with a browser open. That's because it's cached loads of stuff it might need - this is instantly freed up if it's needed for something else. Use resmon and you'll see what I mean. I'll often see only 1 or 2mb "free" as the system caches stuff it thinks I might need - likely why W7 works so well.
Cheers,
Scoob.
