Radeon HD 6870 vs Radeon R9 M275X

Intro

Compare all of that to the Radeon R9 M275X, which uses a 28 nm design. AMD has set the core speed at 900 MHz. The GDDR5 RAM runs at a frequency of 1125 MHz on this model. It features 640 SPUs along with 40 TAUs and 16 Rasterization Operator Units.

Display Graphs

Hide Graphs

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

The Radeon HD 6870, in theory, should perform much faster than the Radeon R9 M275X overall. (explain)

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

Texel Rate

The Radeon HD 6870 should be quite a bit (more or less 40%) faster with regards to anisotropic 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 much (approximately 100%) better at AA than the Radeon R9 M275X, and also will be capable of handling higher screen resolutions better. (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 maximum amount of data (in units of MB per second) that can be moved across the external memory interface in one second. The number is calculated by multiplying the interface width by its memory clock speed. If it uses DDR RAM, it should be multiplied by 2 again. If 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, High Dynamic Range and high resolutions.

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

Pixel Rate: Pixel rate is the maximum number of pixels the graphics card could possibly write to the local memory per second - measured in millions of pixels per second. The figure is worked out by multiplying the number of colour ROPs by the the core speed of the card. ROPs (Raster Operations Pipelines - also sometimes called Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel fill rate also depends on quite a few other factors, most notably the memory bandwidth - the lower the memory bandwidth is, the lower the ability to reach the max fill rate.