Radeon HD 6870 vs Radeon R9 M275X

Intro

Compare those specifications to the Radeon R9 M275X, which makes use of a 28 nm design. AMD has set the core frequency at 900 MHz. The GDDR5 RAM is set to run at a frequency of 1125 MHz on this specific model. It features 640 SPUs along with 40 Texture Address Units and 16 Rasterization Operator Units.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon R9 M275X		50 Watts
Radeon HD 6870		151 Watts
	Difference: 101 Watts (202%)

Memory Bandwidth

Performance-wise, the Radeon HD 6870 should in theory be much better than the Radeon R9 M275X in general. (explain)

Radeon HD 6870		134400 MB/sec
Radeon R9 M275X		72000 MB/sec
	Difference: 62400 (87%)

Texel Rate

The Radeon HD 6870 is much (more or less 40%) more effective at texture filtering than the Radeon R9 M275X. (explain)

Radeon HD 6870		50400 Mtexels/sec
Radeon R9 M275X		36000 Mtexels/sec
	Difference: 14400 (40%)

Pixel Rate

The Radeon HD 6870 is a lot (approximately 100%) more effective at FSAA than the Radeon R9 M275X, and also capable of handling higher screen resolutions while still performing well. (explain)

Radeon HD 6870		28800 Mpixels/sec
Radeon R9 M275X		14400 Mpixels/sec
	Difference: 14400 (100%)

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 data (in units of MB per second) that can be transferred past the external memory interface in a second. It is calculated by multiplying the bus width by its memory speed. In the case of DDR type RAM, it must be multiplied by 2 once again. If it uses DDR5, multiply by 4 instead. The higher the card's memory bandwidth, the faster 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 can be processed in one second. This is worked out by multiplying the total number of texture units of the card by the core clock speed of the chip. The higher the texel rate, the better the video card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels processed in a second.

Pixel Rate: Pixel rate is the maximum number of pixels that the graphics card can possibly write to its local memory in one second - measured in millions of pixels per second. The figure is calculated by multiplying the number of Raster Operations Pipelines by the the core speed of the card. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel rate is also dependant on quite a few other factors, especially the memory bandwidth of the card - the lower the bandwidth is, the lower the potential to get to the max fill rate.