Radeon HD 3870 1GB vs Radeon R9 M265X

Intro

Compare all of that to the Radeon R9 M265X, which has core speeds of 575 MHz on the GPU, and 1125 MHz on the 2048 MB of GDDR5 memory. 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

Both cards have the exact same bandwidth, so in theory they should perform exactly the same. (explain)

Texel Rate

The Radeon R9 M265X will be a lot (approximately 85%) faster with regards to 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 running with high levels of AA is important to you, then the Radeon HD 3870 1GB is the winner, by far. (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: Memory bandwidth is the largest amount of information (in units of megabytes per second) that can be moved across the external memory interface in a second. It is calculated by multiplying the interface width by its memory speed. If the card has DDR memory, it should be multiplied by 2 again. If it uses 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, HDR and higher screen resolutions.

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

Pixel Rate: Pixel rate is the maximum amount of pixels the graphics card can possibly record to its local memory per second - measured in millions of pixels per second. The figure is calculated by multiplying the amount of ROPs by the the core speed of the card. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel rate also depends on lots of other factors, especially the memory bandwidth - the lower the bandwidth is, the lower the ability to reach the max fill rate.