I have got 1 Sapphire ATI Radeon R9 290 Tri-X OC (UEFI) 4GB PCI-Express Video Card I am not sure how well this card alone will do, during trying to mine some Decred
There was a note about this on the wiki: https://wiki.decred.org/GPU_Mining#Future_Work It shouldn't be that much work for someone who knows what they're doing since ccminer already supports 14 rounds of blake-256. I hope I can get it to it soon or someone beats me to it.
I believe Nvidia can work with present OCL miner - just a bit more fiddling. Not sure if my notebook GeForce GT 525M can be used though
Nvidia does work with Linux - even the speed is not breathtaking with present cgminer : Cgminer Hardware Performance
I believe Nvidia cards work just fine but you need some sort of ATI SDK tool that installs CUDA or OPENCL. I've done this before for another coin. ATI cards are faster.. In fact, I'm gonna try right now, I have a spare pc and an older Geforce 9800 GTX+ just to find out if I can mine with it..
A 750Ti will do more then 5 times that, and use about 1/5th of the power. And they are getting CHEAP!
strange thing is that i'm getting 50% rejects Solved rejects on NVIDIA card by adding this line to cgminer --no-submit-stale --scan-time 2 --queue 0