Radeon HD 3850 1GB vs Radeon R9 M275X

Intro

Compare all of that to the Radeon R9 M275X, which comes with a clock frequency of 900 MHz and a GDDR5 memory frequency of 1125 MHz. It also features a 128-bit bus, and makes use of a 28 nm design. It is made up of 640 SPUs, 40 TAUs, and 16 Raster Operation Units.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon R9 M275X		50 Watts
Radeon HD 3850 1GB		75 Watts
	Difference: 25 Watts (50%)

Memory Bandwidth

In theory, the Radeon R9 M275X should be a lot faster than the Radeon HD 3850 1GB overall. (explain)

Radeon R9 M275X		72000 MB/sec
Radeon HD 3850 1GB		52992 MB/sec
	Difference: 19008 (36%)

Texel Rate

The Radeon R9 M275X will be quite a bit (about 237%) faster with regards to AF than the Radeon HD 3850 1GB. (explain)

Radeon R9 M275X		36000 Mtexels/sec
Radeon HD 3850 1GB		10688 Mtexels/sec
	Difference: 25312 (237%)

Pixel Rate

The Radeon R9 M275X is much (approximately 35%) more effective at full screen anti-aliasing than the Radeon HD 3850 1GB, and also will be able to handle higher screen resolutions without slowing down too much. (explain)

Radeon R9 M275X		14400 Mpixels/sec
Radeon HD 3850 1GB		10688 Mpixels/sec
	Difference: 3712 (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 information (counted in MB per second) that can be transported past the external memory interface in one second. The number is calculated by multiplying the card's interface width by its memory clock speed. In the case of DDR RAM, it should be multiplied by 2 again. If DDR5, multiply by ANOTHER 2x. The better the card's memory bandwidth, the better the card will be in general. It especially helps with anti-aliasing, High Dynamic Range and high resolutions.

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

Pixel Rate: Pixel rate is the maximum amount of pixels the video card could possibly write to the local memory in a second - measured in millions of pixels per second. The figure is worked out by multiplying the amount of colour ROPs by the the core 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 - the lower the bandwidth is, the lower the potential to get to the maximum fill rate.