Can I SLi two GTX650s of a different brand?

[tom66]

My friend gave me his old MSI GTX 650 Ti Boost, it has a problem with the fans but otherwise it works.
Provided I can fix the fans, can I use this with my Asus GTX 650 Ti Boost in an SLI config?

[SteveNielsen]

Re: Can I SLi two GTX650s of a different brand?

It looks like the answer is yes:

https://en.wikipedia.org/wiki/Scalable_Link_Interface

Caveats

Not all motherboards with multiple PCI-Express x16 slots support SLI. Recent motherboards as of August 2014 that support it are Intel's Z and X series chipsets (Z68, Z77, Z87, Z97, X79 and X99) and AMD's 990FX chipset.[8] Aside from a few exceptions, older motherboards needed certain models of nForce chipsets to support SLI.
In an SLI configuration, cards can be of mixed manufacturers, card model names, BIOS revisions or clock speeds. However, they must be of the same GPU series (e.g. 8600, 8800) and GPU model name (e.g. GT, GTS, GTX).[9] There are rare exceptions for "mixed SLI" configurations on some cards that only have a matching core codename (e.g. G70, G73, G80, etc.), but this is otherwise not possible, and only happens when two matched cards differ only very slightly, an example being a differing amount of video memory, stream processors, or clockspeed. In this case, the slower/lesser card becomes dominant, and the other card matches. Another exception is the GTS 250, which can be paired with the 9800 GTX+, as the GTS 250 GPU is a rebadged 9800 GTX+ GPU.
In cases where two cards are not identical, the faster card – or the card with more memory - will run at the speed of the slower card or disable its additional memory. (Note that while the FAQ still claims different memory size support, the support has been removed since revision 100.xx of NVIDIA's Forceware driver suite.)

[diif]

Re: Can I SLi two GTX650s of a different brand?

What motherboard have you got ? Some with 2 PCI-E x16 slots were only crossfire (AMDs) solution and not the more expensive to license SLI.
And whilst technically you should, i've come across an issue with identical cards not working due to different firmware/bios (can't remember the details) so give it a try. You might need to buy the SLI link.
And make sure your PSU is up to the job.