POWERCOLOR RADEON R9 290X is Hawaii clocked at 1050Mhz with 4GB GDDR5 clocked at 5400Mhz. Powercolor Radeon R9 290x has memory interface of 512Bits with 2816 shader processors with directx 11.2. Powercolor Radeon R9 280x is Tahiti clocked at 1070Mhz with 3GB GDDR5 clocked at 6200Mhz. Powercolor Radeon R9 280x has memory interface of 384Bits with 1248 shader processors with support for directx 11.2. Benchmark software is Battlefield 3, Bioshock Infinite, Dirt 3, Farcry 3, Hitman Absolution, Max Payne 3, Resident Evil 6 and Tomb Raider 3. CPU is AMD FX 8350 with Gigabyte GA78LMT S2P using Windows 8."