Phoronix posted a review on the AMD Radeon R9 290 running under Linux

AMD unveiled the Radeon R9 290 graphics card at the beginning of November as one step down from the new flagship Radeon R9 290X graphics card. Numerous Windows reviews praised the graphics card for its great performance, but what wasn't clear at the time was how the Linux performance and compatibility was for this new $399 USD graphics card. AMD hadn't offered any review samples to Phoronix for conducting any Linux-based testing and benchmarking, but it's more clear now why that didn't happen: the Linux performance isn't stellar. I bought an XFX Radeon R9 290 and now there's many Linux benchmarks coming out of this graphics card that's riddled by what might be driver issues. I already regret having purchased the AMD Radeon R9 290 for use on Linux; the graphics card is hot, power hungry, noisy, and the OpenGL results aren't too good.

  AMD Radeon R9 290 Review On Linux