Can I run GTX 680 2GB and 4GB in SLI?

[JB00Junior]

Hi Guys

So I recently just treated myself to a new gaming rig:

Chassis: CM HAF 922
CPU: i7 3930K
PSU: XFX 1050 watt black edition 80+ Gold
MOBO: Asus X79 Deluxe
GPU: 2x EVGA GTX 680 SC Signature 2GB running in SLI
RAM: 2x Kingston Hyper X 8GB 1600 kit
HD's: PATRIOT PYRO 60GB SATA 3, and 2.5" SEAGATE 1TB 7200RPM
DVD ROM and will get Blu Ray on pay day.

I've just read a forum on the GTX 680 2GB VS the GTX 680 4GB as to which is more future proof. Some people feel the 2GB isn't enough vram for future games, as some games like metro 2033 allready uses like 1.9 gb vram, thus making the 2GB card less future proof than the 4GB version.

My whole idea was to buy a gaming system that will take at least 3 - 5 years befor I need to make major upgrades to cope with the latest games of that time. However, when I bought my rig a few weeks ago, the 4gb version wasn't available in my country, (South Africa) so I got the 2GB version thinking that is more that enough. It will annoy the heck out of me if a powerful card like the 680 might suffer due to a lack of enough vram with later and more demanding games.

My questions are, can I run, say another evga gtx 680 4gb card with my other two gtx 680 2gb cards in 3 way sli? and then just use the 4gb one as the dedicated gpu or what ever they call it? Also, is my PSU big enough to handle 3 way sli? CPU bottleneck with 3 way sli?

PS, I'm using a 27 inch Samsung S27A950D 3D monitor. I play my games at 1080P and in 3D.

Thanx guys

 

[crazyeyesreaper]

yes they should work in SLI, however you will limit the 4GB card to 2GB thus worthless to get one if you want SLI 4GB sell the 2gb buy two 4gb otherwise your wasting cash pairing a 2GB to a 4GB

 

[erocker]

Just get another 2gb card. At your resolution, even with 3D the extra Vram will only slow things down a little due to higher latencies.

 

[oinkypig]

shenanigans

 

[JB00Junior]

I see, thanx. Don't really want to sell my 2 680's now and wait for 2 4gb's. This is Africa, things take 10 time longer to get here than they do in 1st world countries. Guess I'll just suffer a bit lower fps with my 2gb's cards.

 

[erocker]

I see, thanx. Don't really want to sell my 2 680's now and wait for 2 4gb's. This is Africa, things take 10 time longer to get here than they do in 1st world countries. Guess I'll just suffer a bit lower fps with my 2gb's cards.

Incorrect, with two 4gb cards you will get lower framerates. Minimal, but lower.

 

[Black Panther]

Incorrect, with two 4gb cards you will get lower framerates. Minimal, but lower.

You mean he'd get lower fps with 2x 4GB cards in SLi than with 2 one being 2GB and the other 4GB?

 

[radrok]

You mean he'd get lower fps with 2x 4GB cards in SLi than with 2 one being 2GB and the other 4GB?

AIB vendor probably had to adjust memory latency on GPUs with 4GB because more memory puts more strain on the memory controller, it's something like RAM and CPUs, the more you add the more hard is to run at a certain speed/latency.

In this article you can clearly see that there is not much of a difference (actually there isn't, because every test I checked yielded same performance at same clocks) between the GTX 680 and the GTX 680 4GB, be warned though, don't compare the two Palit's Jetstream because the 2GB version is clocked above reference and the 4GB version is clocked like reference, so compare the 4GB version with the GTX 680 reference, not Palits 2GB!

http://www.guru3d.com/article/palit-geforce-gtx-680-4gb-jetstream-review/24