Radeon HD 4790 vs Radeon R9 M275X

Intro

Compare all that to the Radeon R9 M275X, which has a core clock frequency of 900 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 Texture Address Units, and 16 ROPs.

Display Graphs

Hide Graphs

Power Usage and Theoretical Benchmarks

Memory Bandwidth

Theoretically, the Radeon HD 4790 should be much faster than the Radeon R9 M275X in general. (explain)

Radeon HD 4790		102400 MB/sec
Radeon R9 M275X		72000 MB/sec
	Difference: 30400 (42%)

Texel Rate

The Radeon R9 M275X is quite a bit (about 88%) better at texture filtering than the Radeon HD 4790. (explain)

Radeon R9 M275X		36000 Mtexels/sec
Radeon HD 4790		19200 Mtexels/sec
	Difference: 16800 (88%)

Pixel Rate

The Radeon R9 M275X will be much (about 50%) more effective at FSAA than the Radeon HD 4790, and able to handle higher resolutions while still performing well. (explain)

Radeon R9 M275X		14400 Mpixels/sec
Radeon HD 4790		9600 Mpixels/sec
	Difference: 4800 (50%)

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 over the external memory interface in one second. The number is worked out by multiplying the card's bus width by the speed of its memory. If the card has DDR type RAM, it should be multiplied by 2 again. If DDR5, multiply by ANOTHER 2x. The better the 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 texture map elements (texels) that are processed in one second. This figure is calculated by multiplying the total texture units by the core speed of the chip. The higher the texel rate, the better the video 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 that the graphics card could possibly write to the local memory in a second - measured in millions of pixels per second. The number is calculated by multiplying the amount of Raster Operations Pipelines by the the core speed of the card. ROPs (Raster Operations Pipelines - also sometimes called Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel output 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.