Looking for Linux gpu stress testing and benchmark software

I recently built a new test bench to test new hardware before I transfer it over to my main rig. My gaming pc is water cooled including the gpu's so I put this together in order to test new gpu's before I go through the trouble of replacing the air coolers with water blocks. I decided to install Linux so I wouldn't have to get another key for windows and to learn more about Linux OS's as I go through the process of testing new hardware. I've installed Ubuntu 15.04 but I'm thinking about switching to Mint or Elementary OS.

Regardless of which distro I use, I would still like some suggestions on the best software to used to stress test and benchmark gpu's for basic functionality before I transfer them to my gaming pc running windows 10. I know Unigine's Valley/Heaven both have Linux versions, which is good. I can compare basic performance between Linux and windows that way. What else could I use on Linux to put a gpu through it's paces before tearing it apart?

Hi maybe this thread will be of interest to you:

https://forum.teksyndicate.com/t/post-your-opengl-linux-benchmarks/86031

Check out page 66.

Linux score (3938) Vs Windows score (4676) Valley 1.0 Bechmark with a GTX 980 done by @Urworstnit3m3r

Phoronix Test Suite

It will run just about all available benchmarks in every available resolution. It includes unigen benchmarks. It is a far more complete solution than just unigen benchmarks alone.

Thanks for the suggestions. I've installed Unigine Valley and Phoronix Test Suite to break in a R9 Fury before transplanting it into my desktop. My next step is replacing the 60 gb hard drive that's on the test bench now so I can install more games that have built in benchmarks. The hard drive is the original 60 gb drive that was in my PS3 from 2007, still kickin.

Phoronix Test Suite has over 450 individual tests. There are entire suites in PTS dedicated to Gaming. It will download and run something like 20+ games multiple times with different settings and resolutions. It will THRASH your system.