Radeon HD 3870 1GB vs Radeon R9 390 8G

Intro

Compare all that to the Radeon R9 390 8G, which has a clock speed of 1000 MHz and a GDDR5 memory frequency of 1500 MHz. It also features a 512-bit bus, and makes use of a 28 nm design. It is comprised of 2560 SPUs, 160 Texture Address Units, and 64 Raster Operation Units.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 3870 1GB		106 Watts
Radeon R9 390 8G		275 Watts
	Difference: 169 Watts (159%)

Memory Bandwidth

In theory, the Radeon R9 390 8G will be 433% faster than the Radeon HD 3870 1GB overall, due to its higher bandwidth. (explain)

Radeon R9 390 8G		384000 MB/sec
Radeon HD 3870 1GB		72000 MB/sec
	Difference: 312000 (433%)

Texel Rate

The Radeon R9 390 8G should be a lot (approximately 1190%) faster with regards to anisotropic filtering than the Radeon HD 3870 1GB. (explain)

Radeon R9 390 8G		160000 Mtexels/sec
Radeon HD 3870 1GB		12400 Mtexels/sec
	Difference: 147600 (1190%)

Pixel Rate

If using a high resolution is important to you, then the Radeon R9 390 8G is the winner, and very much so. (explain)

Radeon R9 390 8G		64000 Mpixels/sec
Radeon HD 3870 1GB		12400 Mpixels/sec
	Difference: 51600 (416%)

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 data (measured in megabytes per second) that can be moved past the external memory interface in a second. It is worked out by multiplying the interface width by its memory clock speed. In the case of DDR RAM, it should be multiplied by 2 again. If it uses DDR5, multiply by ANOTHER 2x. The higher 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 texture map elements (texels) that are applied per second. This number is calculated by multiplying the total number of texture units by the core speed of the chip. The better this number, the better the 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 maximum amount of pixels that the graphics card could possibly write to its local memory per second - measured in millions of pixels per second. The number is calculated by multiplying the number of colour ROPs by the the core speed of the card. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel output rate is also dependant on many other factors, most notably the memory bandwidth - the lower the bandwidth is, the lower the potential to reach the maximum fill rate.