Radeon HD 3870 512MB vs Radeon R9 M265X

Intro

Compare those specifications to the Radeon R9 M265X, which has a clock speed of 575 MHz and a GDDR5 memory speed of 1125 MHz. It also uses a 128-bit bus, and uses a 28 nm design. It features 640 SPUs, 40 TAUs, and 16 Raster Operation Units.

Display Graphs

Hide Graphs

Power Usage and Theoretical Benchmarks

Memory Bandwidth

Theoretically speaking, the Radeon R9 M265X should perform quite a bit faster 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 quite a bit (about 85%) better at texture 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

If running with high levels of AA is important to you, then the Radeon HD 3870 512MB is a better choice, and very much so. (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: Memory bandwidth is the max amount of data (measured in megabytes per second) that can be transferred across the external memory interface in a second. It's worked out by multiplying the interface width by the speed of its memory. In the case of DDR RAM, it should be multiplied by 2 again. If it uses DDR5, multiply by 4 instead. The better the memory bandwidth, the better the card will be in general. It especially helps with AA, High Dynamic Range and higher screen resolutions.

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

Pixel Rate: Pixel rate is the maximum number of pixels the video card can possibly write to its local memory per second - measured in millions of pixels per second. The figure is worked out by multiplying the amount of Render Output Units by the the core 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 quite a few other factors, especially the memory bandwidth of the card - the lower the bandwidth is, the lower the ability to reach the maximum fill rate.