SLI-Same Gpus,diffrent memory?

[Nevakonaza]

Is it true that you cannot SLI a graphics card with the same GPUs but diffrent memory size on the cards?

For example...

Card 1 - GTX 460 768Mb
Card 2 - GTX 460 1GB

I was planning to SLI,but cannot fit another regular GTX 460 in my case due to where Gigabyte put the second Pci-e slot on my mobo,the only way id be able to SLI is if i had a really thin cooler GTX 460 like the up comming KFA2 GTX 460 which uses a slim cooler...

although i asked them and they dont currently have plans for a 768mb version...

 

[lay-z-boy]

As far as I understand, you can sli the same core but they will run at the LCD. So in your case the 1gb card would restrict the amount of memory available to 768mb and have the clock speeds cut, it will also be waiting on the slower card all the time due to the 768mb having more than just a memory size nerf.

What case and motherboard do you currently have?

 

[ColonelCage]

I'm almost sure you can't. Originally they had to be two identical cards, now you can use different manufacturers, and even cards with different clocks. But not different memory sizes, these are essentially two completely different cards anyway.

 

[appletree]

Problem here is that the 768 MB and 1GB version do not differ only in the memory size, but they are different GPUs as well, also have a look here: http://www.tomshardware.co.uk/forum/245454-15-crossfire-faqs

So,you generally can't pair a 7800GTX 256 with 7800GTX 512 or GTX 460 768MB with its 1GB version unless you use some 3rd party applications(which isn't recommended).
However,if you manage to run them in SLI,(for example a 7800GTX 256 with 7800GTX 512)the second card will lower its memory to 256MB in order to match it with the other card

 

[Nevakonaza]

arghh

What case and motherboard do you currently have?

My Mobo is - Gigabyte GA-P55-US3L

my case -Coolermaster CM690

Another card wont fit because the top of my power supply is in the way,you will get what i mean from lookin at my mobo pic

 

[cmndr_andi]

Unfortunately, that motherboard doesn't support SLI (crossfire only) and the second main PCIE slot only runs at x4 speed.

 

[appletree]

Well, given the circumstances it seems like the only reasonable upgrade path for you is to sell your 460 and buy some more powerful card like hd 6950 or gtx 560

 

[MeatLoaf]

Normally you can run SLI with different memory sizes. However only the lower amount of RAM will be available.

With the GTX 460 tho i dont know as its not only the memory size thats different.

 

[i7_860]

Yeah confirmed it would basically be SLi'ed @ 768mb for both cards

 

[KiiYzOo]

Why don't you sell your motherboard and buy a cheap atx p55 board that will be able to run sli?

 

[Nevakonaza]

Unfortunately, that motherboard doesn't support SLI (crossfire only) and the second main PCIE slot only runs at x4 speed.

Oh man i did not know that,well thats that plan out the window then

Well, given the circumstances it seems like the only reasonable upgrade path for you is to sell your 460 and buy some more powerful card like hd 6950 or gtx 560

I did actually consider getting a 6950 and unlocking it to 6970,but at £250 ish its a bit expensive :/

Im gonna wait to see how much the GTX 560 is.