Radeon HD 3870 512MB vs Radeon R9 M275X

Intro

Compare all of that to the Radeon R9 M275X, which comes with a GPU core clock speed of 900 MHz, and 2048 MB of GDDR5 RAM running at 1125 MHz through a 128-bit bus. It also is made up of 640 Stream Processors, 40 Texture Address Units, and 16 Raster Operation Units.

Display Graphs

Hide Graphs

Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon R9 M275X		50 Watts
Radeon HD 3870 512MB		106 Watts
	Difference: 56 Watts (112%)

Memory Bandwidth

The Radeon R9 M275X should theoretically be much faster than the Radeon HD 3870 512MB overall. (explain)

Radeon R9 M275X		72000 MB/sec
Radeon HD 3870 512MB		57600 MB/sec
	Difference: 14400 (25%)

Texel Rate

The Radeon R9 M275X is a lot (more or less 190%) faster with regards to AF than the Radeon HD 3870 512MB. (explain)

Radeon R9 M275X		36000 Mtexels/sec
Radeon HD 3870 512MB		12400 Mtexels/sec
	Difference: 23600 (190%)

Pixel Rate

If running with a high screen resolution is important to you, then the Radeon R9 M275X is superior to the Radeon HD 3870 512MB, but it probably won't make a huge difference. (explain)

Radeon R9 M275X		14400 Mpixels/sec
Radeon HD 3870 512MB		12400 Mpixels/sec
	Difference: 2000 (16%)

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: Memory bandwidth is the largest amount of information (measured in MB per second) that can be moved past the external memory interface in a second. It is calculated by multiplying the card's bus width by its memory speed. If the card has DDR type RAM, it should be multiplied by 2 once again. If it uses DDR5, multiply by ANOTHER 2x. The better the bandwidth is, the better the card will be in general. It especially helps with anti-aliasing, HDR and higher screen resolutions.

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

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