Radeon HD 7870 vs Radeon R9 M290X

Intro

Compare those specs to the Radeon R9 M290X, which features 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 is made up of 1280 Stream Processors, 80 TAUs, and 32 ROPs.

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 exactly the same bandwidth, so theoretically they should perform exactly the same. (explain)

Texel Rate

The Radeon HD 7870 is a 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 using high levels of AA is important to you, then the Radeon HD 7870 is a better choice, not by a very large margin though. (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 max amount of information (counted in MB per second) that can be moved past the external memory interface in a second. The number is worked out by multiplying the interface width by its memory speed. If the card has DDR memory, it should be multiplied by 2 once again. If DDR5, multiply by ANOTHER 2x. The better the bandwidth is, the better the card will be in general. It especially helps with anti-aliasing, High Dynamic Range and high resolutions.

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

Pixel Rate: Pixel rate is the maximum number of pixels the graphics card can possibly write to its local memory in a second - measured in millions of pixels per second. The number is calculated by multiplying the amount of ROPs 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 output rate also depends on lots of other factors, most notably the memory bandwidth of the card - the lower the bandwidth is, the lower the ability to get to the max fill rate.