Radeon HD 3850 512MB vs Radeon R9 M275X

Intro

Compare those specifications to the Radeon R9 M275X, which uses a 28 nm design. AMD has set the core speed at 900 MHz. The GDDR5 memory runs at a speed of 1125 MHz on this specific model. It features 640 SPUs along with 40 Texture Address Units and 16 ROPs.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon R9 M275X		50 Watts
Radeon HD 3850 512MB		75 Watts
	Difference: 25 Watts (50%)

Memory Bandwidth

As far as performance goes, the Radeon R9 M275X should theoretically be quite a bit better than the Radeon HD 3850 512MB in general. (explain)

Radeon R9 M275X		72000 MB/sec
Radeon HD 3850 512MB		52992 MB/sec
	Difference: 19008 (36%)

Texel Rate

The Radeon R9 M275X should be much (about 237%) more effective at texture filtering than the Radeon HD 3850 512MB. (explain)

Radeon R9 M275X		36000 Mtexels/sec
Radeon HD 3850 512MB		10688 Mtexels/sec
	Difference: 25312 (237%)

Pixel Rate

The Radeon R9 M275X should be much (about 35%) faster with regards to full screen anti-aliasing than the Radeon HD 3850 512MB, and also will be capable of handling higher screen resolutions more effectively. (explain)

Radeon R9 M275X		14400 Mpixels/sec
Radeon HD 3850 512MB		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 (in units of MB per second) that can be transported past the external memory interface in one second. It's calculated by multiplying the bus width by its memory speed. In the case of DDR type memory, it must be multiplied by 2 once again. If DDR5, multiply by 4 instead. The higher the bandwidth is, 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 texture map elements (texels) that can be applied per second. This number is worked out by multiplying the total amount of texture units by the core clock speed of the chip. The better this number, the better the graphics card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels processed in a second.

Pixel Rate: Pixel rate is the most pixels that the graphics card can possibly record to its local memory in a second - measured in millions of pixels per second. The figure is worked out by multiplying the amount of Render Output Units by the the core clock speed. ROPs (Raster Operations Pipelines - also called Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel output rate also depends on quite a few other factors, especially the memory bandwidth of the card - the lower the memory bandwidth is, the lower the ability to get to the maximum fill rate.