Radeon HD 7870 vs Radeon R9 M290X

Intro

Compare all of that to the Radeon R9 M290X, which comes with a GPU core clock speed of 850 MHz, and 4096 MB of GDDR5 RAM set to run at 1200 MHz through a 256-bit bus. It also features 1280 Stream Processors, 80 Texture Address Units, and 32 Raster Operation Units.

Display Graphs

Hide Graphs

Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon R9 M290X		100 Watts
Radeon HD 7870		175 Watts
	Difference: 75 Watts (75%)

Memory Bandwidth

Both cards have the exact same bandwidth, so theoretically they should have identical performance. (explain)

Texel Rate

The Radeon HD 7870 is a little bit (about 18%) better at anisotropic filtering than the Radeon R9 M290X. (explain)

Radeon HD 7870		80000 Mtexels/sec
Radeon R9 M290X		68000 Mtexels/sec
	Difference: 12000 (18%)

Pixel Rate

If running with lots of anti-aliasing is important to you, then the Radeon HD 7870 is superior to the Radeon R9 M290X, but not by far. (explain)

Radeon HD 7870		32000 Mpixels/sec
Radeon R9 M290X		27200 Mpixels/sec
	Difference: 4800 (18%)

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 largest amount of data (measured in MB per second) that can be transferred past the external memory interface in a second. It's calculated by multiplying the card's bus width by the speed of its memory. In the case of DDR memory, it should be multiplied by 2 again. If DDR5, multiply by 4 instead. The higher the 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 number of texture map elements (texels) that are processed in one second. This figure is worked out by multiplying the total texture units of the card by the core speed of the chip. The higher this number, the better the video 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 most pixels the video card can possibly write to the local memory per second - measured in millions of pixels per second. The number is calculated by multiplying the number of Render Output Units by the clock 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 rate is also dependant on quite a few other factors, especially the memory bandwidth - the lower the memory bandwidth is, the lower the ability to get to the maximum fill rate.