In terms of overall gaming performance, the graphical capabilities of the AMD Radeon R9 280X Crossfire are significantly better than the AMD Radeon R9 380.

The Radeon R9 380 has a 120 MHz higher core clock speed than the R9 280X, but the R9 280X has 144 more Texture Mapping Units than the Radeon R9 380. As a result, the R9 280X exhibits a 109 GTexel/s better Texture Fill Rate than the Radeon R9 380. This still holds weight but shader performance is generally more relevant, particularly since both of these GPUs support at least DirectX 10.

The Radeon R9 380 has a 120 MHz higher core clock speed than the R9 280X, but the R9 280X has 32 more Render Output Units than the Radeon R9 380. As a result, the R9 280X exhibits a 23.4 GPixel/s better Pixel Fill Rate than the Radeon R9 380. However, both GPUs support DirectX 9 or above, and pixeling performance is only really relevant when comparing older cards.

The Radeon R9 380 was released over a year more recently than the R9 280X, and so the Radeon R9 380 is likely to have better driver support, meaning it will be more optimized for running the latest games when compared to the R9 280X.

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 R9 280X has 4096 MB more video memory than the Radeon R9 380, so is likely to be much better at displaying game textures at higher resolutions. This is supported by the fact that the R9 280X also has superior memory performance overall.

The R9 280X has 400 GB/sec greater memory bandwidth than the Radeon R9 380, which means that the memory performance of the R9 280X is massively better than the Radeon R9 380.

The Radeon R9 380 has 1792 Shader Processing Units and the Radeon R9 280X Crossfire has 4096. However, the actual shader performance of the Radeon R9 380 is 1478. The R9 280X having 2618 better shader performance and an altogether better performance when taking into account other relevant data means that the R9 280X delivers a massively smoother and more efficient experience when processing graphical data than the Radeon R9 380.

The Radeon R9 380 requires 190 Watts to run and the Radeon R9 280X Crossfire requires 550 Watts. We would recommend a PSU with at least 500 Watts for the Radeon R9 380 and a PSU with at least 1000 Watts for the R9 280X. The R9 280X requires 360 Watts more than the Radeon R9 380 to run. The difference is significant enough that the R9 280X may have an adverse affect on your yearly electricity bills in comparison to the Radeon R9 380.