Which GPU would be the most adequate for my situation?

[NeutronPCXT]

Hi guys, this is NeutronPCXT here. I've been using Dolphin for while now and as I've been emulating more and more games recently, I've noticed that even with my new build, which has an i5 6500 along with a GTS 250, performance hasnt been the best in games like Super Smash BB and Sonic Riders, and of course, the Legend of Zelda TP(all on 720p, 480p is just too low for me). Which is strange considering that Super Smash BB and Sonic Riders are easy games to run, especially with a Skylake i5. And let's mention that I'm on Xubuntu 16.04 using 340.96 proprietary drivers.

So I've come to the conclusion that my GTS 250 has finally reached its limit. So, I'd like to ask you which GPU should I buy to get better performance in Dolphin on Xubuntu 16.04, from AMD or from Nvidia, since I read that on the Dolphin FAQ, that due to additional hardware, AMD GPUs run better than Nvidia's counterparts. So which company should I choose, and which GPU would be the most adequate?

Note: I'm running Dolphin 5.0-119. I compiled it today.
Thanks in advance. Ask any questions if it helps you to help me .
Games I'm trying to run well at least at 720p: Sonic Riders, SSBB and LoZ TP.

[KHg8m3r]

AMD has shitty drivers for Linux. Go with Nvidia.
And where did you read that we recommend AMD over Nvidia?

[NeutronPCXT]

Thanks for the answer. And I probably misunderstood what was written in relation to integer math in the FAQ. I should've slept a bit more.
Thanks anyway!
NeutronPCXT

[admin89]

Maxwell GTX 750ti can handle up to 4xIR (2560x2112) , consume 250% less power , run much cooler (55 degree Celsius at full load) , fully support directx12 and it's only $100

[Nintendo Maniac 64]

AMD has shitty drivers for Linux. Go with Nvidia.

Unless you want to use the open-source drivers, then the situation is the exact opposite for new GPUs (though I believe Intel of all companies actually has the best open-source GPU drivers?).