Radeon HD 4890 2GB vs Radeon R7 250X

Intro

Compare that to the Radeon R7 250X, which has GPU core speed of 1000 MHz, and 1024 MB of GDDR5 RAM running at 1125 MHz through a 128-bit bus. It also is comprised of 640 SPUs, 40 TAUs, and 16 Raster Operation Units.

Display Graphs

Hide Graphs

Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon R7 250X		95 Watts
Radeon HD 4890 2GB		190 Watts
	Difference: 95 Watts (100%)

Memory Bandwidth

In theory, the Radeon HD 4890 2GB should perform much faster than the Radeon R7 250X in general. (explain)

Radeon HD 4890 2GB		124800 MB/sec
Radeon R7 250X		72000 MB/sec
	Difference: 52800 (73%)

Texel Rate

Both cards have exactly the same texel rate, so in theory they should perform equally good at at AF. (explain)

Pixel Rate

Both cards have the exact same pixel fill rate, so theoretically they should perform equally good at at anti-aliasing, and be able to handle the same screen resolutions. (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.

Price Comparison

Specifications

Memory Bandwidth: Bandwidth is the max amount of information (in units of megabytes per second) that can be moved across the external memory interface in one second. It's calculated by multiplying the card's bus width by the speed of its memory. In the case of DDR type memory, the result should be multiplied by 2 again. If it uses DDR5, multiply by ANOTHER 2x. The higher the bandwidth is, the faster 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 can be processed per second. This number is calculated by multiplying the total number of texture units of the card by the core speed of the chip. The better the texel rate, the better the card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels processed per second.

Pixel Rate: Pixel rate is the maximum amount of pixels the video card can possibly write to the local memory in a second - measured in millions of pixels per second. Pixel rate is worked out by multiplying the amount of Raster Operations Pipelines by the the core speed of the card. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel output rate also depends on lots of other factors, especially the memory bandwidth - the lower the bandwidth is, the lower the potential to reach the maximum fill rate.