Radeon HD 4790 vs Radeon R9 M270X

Intro

Compare all that to the Radeon R9 M270X, which uses a 28 nm design. AMD has clocked the core frequency at 725 MHz. The GDDR5 RAM is set to run at a speed of 1125 MHz on this card. 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

The Radeon HD 4790 should in theory perform much faster than the Radeon R9 M270X in general. (explain)

Radeon HD 4790		102400 MB/sec
Radeon R9 M270X		72000 MB/sec
	Difference: 30400 (42%)

Texel Rate

The Radeon R9 M270X is a lot (about 51%) more effective at texture filtering than the Radeon HD 4790. (explain)

Radeon R9 M270X		29000 Mtexels/sec
Radeon HD 4790		19200 Mtexels/sec
	Difference: 9800 (51%)

Pixel Rate

If using lots of anti-aliasing is important to you, then the Radeon R9 M270X is superior to the Radeon HD 4790, and very much so. (explain)

Radeon R9 M270X		11600 Mpixels/sec
Radeon HD 4790		9600 Mpixels/sec
	Difference: 2000 (21%)

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 maximum amount of information (in units of MB per second) that can be transported over the external memory interface in a second. The number is calculated by multiplying the card's bus width by the speed of its memory. If the card has DDR memory, it should 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 anti-aliasing, High Dynamic Range and higher screen resolutions.

Texel Rate: Texel rate is the maximum number of texture map elements (texels) that can be applied in one second. This is calculated by multiplying the total amount of texture units by the core speed of the chip. The better 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 per second.

Pixel Rate: Pixel rate is the most pixels that the graphics card could possibly write to the local memory per second - measured in millions of pixels per second. Pixel rate is worked out by multiplying the amount of Render Output Units 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 quite a few other factors, especially the memory bandwidth of the card - the lower the bandwidth is, the lower the potential to reach the max fill rate.