gtx 460 for sli but differnt amounts of vram (768 and 1024)

but shouldn't it just use the smaller amout of the two??

No. That would be the case if you had identical cards with different amounts of VRAM but the 1GB and 768MB versions of that card are too different. Different memory bus and a different number of shaders as well as different VRAM size. If you had a 1GB and a 2GB GTX 460 and both had the same 256 bit memory bus then it would work. I believe they also made later GTX 460 cards with 1GB and a smaller 192 bit bus but they were called GTX 460 SE or something similar. That card would work with your 768MB card.

The earlier 1GB 256 bit cards were the most powerful and the best. I still have an EVGA GTX 460 1GB Superclocked sitting in a box as an extra card. They were great cards in their day and I used it for years.

when i use GPU-Z it saying that everything is the same except for the memory size (if this even make a difference xD if it doesn't i appreciate the quick response and help)

ROPs and memory bus are different.'

http://www.anandtech.com/show/3809/nvidias-geforce-gtx-460-the-200-king/1

I used mine from 2010-2013 so I am familiar with the cards

I was always going to Sli but the single 460 1GB was so good I never got around to it. The 1GB of VRAM proved to be the weak spot at least with the newest "next gen" games. At least at 1920 x 1080.

thanks for your help im just gonna go get a newr video card then lol

A single GTX 460 1GB will max just about every game released before 2013 at 1920 x 1080 so take that into account. The one exception I remember was Metro 2033. I had to turn down graphics quality for that one. I figured go big or go home so I replaced the 460 with this GTX 780. No more worries for a few years!

Glad to help!