SLI: 4GB GTX 680 and 2GB GTX 680?

donnniegoat

Junior Member
Jan 7, 2012
2
0
0
I had two 2GB GTX 680s in an SLI setup. One of my cards failed. I was under warranty with the builder that put together the computer for me, and asked for a replacement card. After some back-and-forth, I received a 4GB version of the card. A couple of things struck me off the bat - the cards are not the same dimensions, and the newer card has a different power setup in terms of plugs it needs. Obviously, it is a 4GB version of the 'primary' 2GB card.

Here is a newegg link (I think) to the 2GB card: http://www.newegg.com/Product/Produc...82E16814130912

And here's a link (I think) to the 4GB version: http://www.newegg.com/Product/Produc...82E16814130801

Can you mix and match cards like this with different memory, if they are based on the same reference card (here, the 680)? Any downside to proceeding this way?

Many thanks for any advice.
 

notty22

Diamond Member
Jan 1, 2010
3,375
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A while back Nvidia stopped supporting different memory sizes in sli.
Pretty sure the driver won't allow sli to be implemented. Bottom line.

Here is a old faq

Can I mix and match graphics cards with different sizes of memory?

When purchasing a second graphics card, you should try to match the memory size so that you are ensured full value and performance from your purchase. However, while it is not recommended, NVIDIA does offer the flexibility to run graphics cards with different sized memory by using CoolBits. Using CoolBits (value set to 18), you can force both of the cards to use the lower of the two memory sizes and operate them together in SLI mode. When dissimilar memory sizes are enabled to work together using CoolBits, the effective memory size for each card becomes the smaller of the memory sizes.
http://www.geforce.com/hardware/technology/sli/faq#c19
Coolbits is no longer supported, from what I've read.


Here is where I read about the change
SLI will not be able to be activated, Coolbits no longer works with our drivers after 310.90, We do not officially support SLI between two cards with different amounts of memory and Coolbits was never an officially supported application. So unfortunately I have no suggestions to get it working with the 314.22 drivers. \
https://forums.geforce.com/default/...-313-96-update-continuing-to-current-drivers/
 
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poohbear

Platinum Member
Mar 11, 2003
2,284
5
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It would be a waste cause it'd be running @ 2gb instead of 4gb. Just sell the 2gb and buy a new 4gb one if that's possible.