Radeon HD 3870 1GB vs Radeon R9 M265X

Intro

Compare those specs to the Radeon R9 M265X, which comes with a GPU core clock speed of 575 MHz, and 2048 MB of GDDR5 RAM set to run at 1125 MHz through a 128-bit bus. It also is made up of 640 SPUs, 40 TAUs, and 16 Raster Operation Units.

Display Graphs

Hide Graphs

Power Usage and Theoretical Benchmarks

Memory Bandwidth

Both cards have the exact same memory bandwidth, so in theory they should have identical performance. (explain)

Texel Rate

The Radeon R9 M265X should be a lot (about 85%) better at AF than the Radeon HD 3870 1GB. (explain)

Radeon R9 M265X		23000 Mtexels/sec
Radeon HD 3870 1GB		12400 Mtexels/sec
	Difference: 10600 (85%)

Pixel Rate

If using high levels of AA is important to you, then the Radeon HD 3870 1GB is the winner, and very much so. (explain)

Radeon HD 3870 1GB		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 max amount of data (counted in MB per second) that can be transferred past the external memory interface in one second. It's worked out by multiplying the interface width by the speed of its memory. In the case of DDR RAM, it must be multiplied by 2 again. If DDR5, multiply by ANOTHER 2x. The higher the bandwidth is, 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 texture map elements (texels) that are applied in one second. This figure is worked out by multiplying the total texture units by the core speed of the chip. The higher the texel rate, the better the graphics 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 amount of pixels the graphics card could possibly record to the local memory in one second - measured in millions of pixels per second. The number is calculated by multiplying the number of colour 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 rate also depends on many other factors, most notably the memory bandwidth of the card - the lower the bandwidth is, the lower the potential to get to the max fill rate.