Cards for SLI

[paulg]

I know there is a thread somewhere here but can't seem to find it.
In SLI mode do the graphics card have to be identical (i.e. Same brand, chip)? I was looking at the Gainward 7800GT with 512mb DDR3 to keep my MSI 7800gt 256mb company. Will this work?
If I added a GTX would it only run at the lower GT speeds in this setup or not work at all?

Thanks

 

[chaparral]

I know there is a thread somewhere here but can't seem to find it.
In SLI mode do the graphics card have to be identical (i.e. Same brand, chip)? I was looking at the Gainward 7800GT with 512mb DDR3 to keep my MSI 7800gt 256mb company. Will this work?
If I added a GTX would it only run at the lower GT speeds in this setup or not work at all?

Thanks

You can't mix a gtx with a gt card..

Read the SLI FAQs here.
http://www.slizone.com/page/slizone_faq.html

 

[paradigm]

I wouldn't add a 512MB card to a 256MB one either. The gainward runs different RAM (much faster), and has a higher clocked core as standard.

I wouldn't like to see the result of trying to load-balance textures with only 256MB of pre-caching space on one card, and 512MB on the other, could produce some dodgy results.

In answer to the original question, no the cards don't need to be identical, but I would assume they need to be the same core type (ie 7800GT with a 7800GT) and have the same amount of memory.