Radeon HD 4790 vs Radeon R9 M270X

Intro

Compare that to the Radeon R9 M270X, which has GPU core speed of 725 MHz, and 2048 MB of GDDR5 memory running at 1125 MHz through a 128-bit bus. It also is made up of 640 SPUs, 40 Texture Address Units, and 16 Raster Operation Units.

Display Graphs

Hide Graphs

Power Usage and Theoretical Benchmarks

Memory Bandwidth

Theoretically speaking, the Radeon HD 4790 should be 42% faster than the Radeon R9 M270X overall, due to its higher data rate. (explain)

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

Texel Rate

The Radeon R9 M270X is quite a bit (about 51%) faster with regards to 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 a high screen resolution is important to you, then the Radeon R9 M270X is a better choice, 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: Memory bandwidth is the largest amount of information (counted in MB per second) that can be moved across the external memory interface in one second. The number is worked out by multiplying the interface width by the speed of its memory. If the card has DDR type memory, it should be multiplied by 2 once again. If DDR5, multiply by ANOTHER 2x. The better the memory bandwidth, the better the card will be in general. It especially helps with anti-aliasing, HDR and high 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 texture units by the core clock 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 applied in a second.

Pixel Rate: Pixel rate is the most pixels that the graphics chip could possibly record to the local memory in a second - measured in millions of pixels per second. The figure is worked out by multiplying the number of colour ROPs by the the card's clock speed. ROPs (Raster Operations Pipelines - also sometimes called Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel output rate also depends on lots of other factors, especially the memory bandwidth of the card - the lower the memory bandwidth is, the lower the potential to get to the max fill rate.