Compare any two graphics cards:
Radeon R9 380X vs Radeon R9 M390X
IntroThe Radeon R9 380X features clock speeds of 970 MHz on the GPU, and 1425 MHz on the 4096 MB of GDDR5 RAM. It features 2048 SPUs along with 128 TAUs and 32 ROPs.
Compare all of that to the Radeon R9 M390X, which features GPU clock speed of 723 MHz, and 4096 MB of GDDR5 RAM running at 1250 MHz through a 256-bit bus. It also is comprised of 2048 SPUs, 128 Texture Address Units, and 32 Raster Operation Units.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
As far as performance goes, the Radeon R9 380X should in theory be a small bit superior to the Radeon R9 M390X in general. (explain)
Texel RateThe Radeon R9 380X should be quite a bit (approximately 34%) more effective at anisotropic filtering than the Radeon R9 M390X. (explain)
Pixel RateIf running with a high resolution is important to you, then the Radeon R9 380X is a better choice, by a large margin. (explain)
Please note that the above 'benchmarks' are all just theoretical - the results were calculated based on the card's specifications, and real-world performance may (and probably will) vary at least a bit.
Please note that the price comparisons are based on search keywords - sometimes it might show cards with very similar names that are not exactly the same as the one chosen in the comparison. We do try to filter out the wrong results as best we can, though.
Memory Bandwidth: Memory bandwidth is the max amount of data (measured in MB per second) that can be transported past the external memory interface in one second. The number is calculated by multiplying the interface width by its memory clock speed. If it uses DDR RAM, the result should be multiplied by 2 once again. If it uses DDR5, multiply by 4 instead. The higher the card's memory bandwidth, the better the card will be in general. It especially helps with AA, High Dynamic Range and higher screen resolutions.
Texel Rate: Texel rate is the maximum texture map elements (texels) that are processed in one second. This figure is calculated by multiplying the total number of texture units of the card by the core speed of the chip. The higher this number, the better the card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels in a second.
Pixel Rate: Pixel rate is the maximum amount of pixels that the graphics chip can possibly write to the local memory in one second - measured in millions of pixels per second. The number is worked out by multiplying the amount of Render Output Units by the the core clock speed. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel rate also depends on quite a few other factors, most notably the memory bandwidth - the lower the memory bandwidth is, the lower the ability to get to the max fill rate.