In terms of overall gaming performance, the graphical capabilities of the AMD Radeon R9 390X XFX Double Dissipation Black 8GB Edition are marginally better than the AMD Radeon R9 390.

The R9 390X has a 90 MHz higher core clock speed and 16 more Texture Mapping Units than the Radeon R9 390. This results in the R9 390X providing 31.8 GTexel/s better texturing performance. This still holds weight but shader performance is generally more relevant, particularly since both of these GPUs support at least DirectX 10.

The R9 390X has a 90 MHz higher core clock speed than the Radeon R9 390 and the same number of Render Output Units. This results in the R9 390X providing 5.8 GPixel/s better pixeling performance. However, both GPUs support DirectX 9 or above, and pixeling performance is only really relevant when comparing older cards.

Both the Radeon R9 390X XFX Double Dissipation Black 8GB Edition and the Radeon R9 390 were released at the same time, so are likely to be quite similar.

Both GPUs exhibit very powerful performance, so it probably isn't worth upgrading from one to the other, as both are capable of running even the most demanding games at the highest settings.

The Radeon R9 390X XFX Double Dissipation Black 8GB Edition and the Radeon R9 390 have the same amount of video memory, but are likely to provide slightly different experiences when displaying game textures at high resolutions.

The memory bandwidth of the Radeon R9 390X XFX Double Dissipation Black 8GB Edition and the Radeon R9 390 are the same, which means the R9 390X and the Radeon R9 390 have equal limitations when it comes to graphical data transfer.

The Radeon R9 390X XFX Double Dissipation Black 8GB Edition has 2816 Shader Processing Units and the Radeon R9 390 has 2560. However, the actual shader performance of the R9 390X is 2609 and the actual shader performance of the Radeon R9 390 is 2176. The R9 390X having 433 better shader performance and an altogether better performance when taking into account other relevant data means that the R9 390X delivers a slightly smoother and more efficient experience when processing graphical data than the Radeon R9 390.

The Radeon R9 390X XFX Double Dissipation Black 8GB Edition requires 300 Watts to run and the Radeon R9 390 requires 275 Watts. We would recommend a PSU with at least 750 Watts for the R9 390X and a PSU with at least 600 Watts for the Radeon R9 390. The R9 390X requires 25 Watts more than the Radeon R9 390 to run. The difference is not significant enough for the R9 390X to have a noticeably larger impact on your yearly electricity bills than the Radeon R9 390.