Radeon HD 3870 512MB vs Radeon R9 M265X

Intro

Compare all that to the Radeon R9 M265X, which makes use of a 28 nm design. AMD has clocked the core speed at 575 MHz. The GDDR5 memory runs at a speed of 1125 MHz on this specific model. It features 640 SPUs along with 40 Texture Address Units and 16 Rasterization Operator Units.

Display Graphs

Hide Graphs

Power Usage and Theoretical Benchmarks

Memory Bandwidth

Performance-wise, the Radeon R9 M265X should theoretically be a lot better than the Radeon HD 3870 512MB overall. (explain)

Radeon R9 M265X		72000 MB/sec
Radeon HD 3870 512MB		57600 MB/sec
	Difference: 14400 (25%)

Texel Rate

The Radeon R9 M265X is a lot (about 85%) better at anisotropic filtering than the Radeon HD 3870 512MB. (explain)

Radeon R9 M265X		23000 Mtexels/sec
Radeon HD 3870 512MB		12400 Mtexels/sec
	Difference: 10600 (85%)

Pixel Rate

The Radeon HD 3870 512MB is quite a bit (about 35%) better at full screen anti-aliasing than the Radeon R9 M265X, and should be able to handle higher resolutions without losing too much performance. (explain)

Radeon HD 3870 512MB		12400 Mpixels/sec
Radeon R9 M265X		9200 Mpixels/sec
	Difference: 3200 (35%)

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 information (in units of MB per second) that can be transported past the external memory interface in a second. It's calculated by multiplying the interface width by the speed of its memory. In the case of DDR memory, it should be multiplied by 2 again. If it uses DDR5, multiply by 4 instead. The better the card's memory bandwidth, the better the card will be in general. It especially helps with anti-aliasing, HDR and high resolutions.

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

Pixel Rate: Pixel rate is the maximum amount of pixels the graphics card can possibly write to the local memory per second - measured in millions of pixels per second. The number is worked out by multiplying the number of ROPs by the the card's clock speed. ROPs (Raster Operations Pipelines - also called Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel output rate is also dependant on lots of other factors, most notably the memory bandwidth of the card - the lower the memory bandwidth is, the lower the ability to get to the max fill rate.