Radeon HD 4870 512MB vs Radeon R9 270X

Intro

Compare those specifications to the Radeon R9 270X, which features GPU clock speed of 1000 MHz, and 2048 MB of GDDR5 memory running at 1400 MHz through a 256-bit bus. It also is made up of 1280 SPUs, 80 TAUs, and 32 Raster Operation Units.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 4870 512MB		150 Watts
Radeon R9 270X		180 Watts
	Difference: 30 Watts (20%)

Memory Bandwidth

Theoretically, the Radeon R9 270X should be much faster than the Radeon HD 4870 512MB in general. (explain)

Radeon R9 270X		179200 MB/sec
Radeon HD 4870 512MB		115200 MB/sec
	Difference: 64000 (56%)

Texel Rate

The Radeon R9 270X will be quite a bit (approximately 167%) better at AF than the Radeon HD 4870 512MB. (explain)

Radeon R9 270X		80000 Mtexels/sec
Radeon HD 4870 512MB		30000 Mtexels/sec
	Difference: 50000 (167%)

Pixel Rate

The Radeon R9 270X will be a lot (approximately 167%) better at FSAA than the Radeon HD 4870 512MB, and also will be capable of handling higher screen resolutions more effectively. (explain)

Radeon R9 270X		32000 Mpixels/sec
Radeon HD 4870 512MB		12000 Mpixels/sec
	Difference: 20000 (167%)

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 maximum amount of information (in units of megabytes per second) that can be moved across the external memory interface in a second. It's calculated by multiplying the bus width by the speed of its memory. If the card has DDR type RAM, the result should be multiplied by 2 again. If DDR5, multiply by 4 instead. The better the bandwidth is, the faster the card will be in general. It especially helps with AA, HDR and high resolutions.

Texel Rate: Texel rate is the maximum amount of texture map elements (texels) that are processed per second. This number is calculated by multiplying the total number of texture units of the card by the core clock 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 most pixels that the graphics card could possibly record to the local memory in a second - measured in millions of pixels per second. Pixel rate is worked out by multiplying the amount of colour ROPs by the the core speed of the card. ROPs (Raster Operations Pipelines - sometimes also referred to as Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel fill rate is also dependant on quite a few other factors, most notably the memory bandwidth - the lower the memory bandwidth is, the lower the ability to reach the maximum fill rate.