Radeon R7 250X 2GB vs Radeon R9 390 8G

Intro

Compare all that to the Radeon R9 390 8G, which has a GPU core clock speed of 1000 MHz, and 8192 MB of GDDR5 RAM running at 1500 MHz through a 512-bit bus. It also is comprised of 2560 Stream Processors, 160 TAUs, and 64 ROPs.

Display Graphs

Hide Graphs

Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon R7 250X 2GB		95 Watts
Radeon R9 390 8G		275 Watts
	Difference: 180 Watts (189%)

Memory Bandwidth

As far as performance goes, the Radeon R9 390 8G should in theory be quite a bit better than the Radeon R7 250X 2GB overall. (explain)

Radeon R9 390 8G		384000 MB/sec
Radeon R7 250X 2GB		72000 MB/sec
	Difference: 312000 (433%)

Texel Rate

The Radeon R9 390 8G should be quite a bit (more or less 300%) faster with regards to anisotropic filtering than the Radeon R7 250X 2GB. (explain)

Radeon R9 390 8G		160000 Mtexels/sec
Radeon R7 250X 2GB		40000 Mtexels/sec
	Difference: 120000 (300%)

Pixel Rate

If running with lots of anti-aliasing is important to you, then the Radeon R9 390 8G is a better choice, by a large margin. (explain)

Radeon R9 390 8G		64000 Mpixels/sec
Radeon R7 250X 2GB		16000 Mpixels/sec
	Difference: 48000 (300%)

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.

Price Comparison

Specifications

Memory Bandwidth: Memory bandwidth is the max amount of information (in units of MB per second) that can be transferred over the external memory interface in one second. It is worked out by multiplying the card's interface width by its memory speed. If the card has DDR type memory, it must be multiplied by 2 again. If it uses DDR5, multiply by 4 instead. The better the card's memory bandwidth, the better the card will be in general. It especially helps with anti-aliasing, HDR and higher screen resolutions.

Texel Rate: Texel rate is the maximum amount of texture map elements (texels) that are applied in one second. This number is worked out by multiplying the total amount of texture units of the card by the core speed of the chip. The higher the texel rate, the better the graphics card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels applied in one second.

Pixel Rate: Pixel rate is the maximum number of pixels the video card could possibly record to its 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 - also sometimes called Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel output rate is also dependant on lots of other factors, most notably the memory bandwidth of the card - the lower the memory bandwidth is, the lower the potential to reach the max fill rate.