Radeon HD 4870 2GB vs Radeon R9 390 8G

Intro

Compare those specifications to the Radeon R9 390 8G, which comes with a clock frequency of 1000 MHz and a GDDR5 memory speed of 1500 MHz. It also features a 512-bit memory bus, and uses a 28 nm design. It features 2560 SPUs, 160 TAUs, and 64 ROPs.

Display Graphs

Hide Graphs

Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 4870 2GB		150 Watts
Radeon R9 390 8G		275 Watts
	Difference: 125 Watts (83%)

Memory Bandwidth

In theory, the Radeon R9 390 8G should perform much faster than the Radeon HD 4870 2GB overall. (explain)

Radeon R9 390 8G		384000 MB/sec
Radeon HD 4870 2GB		115200 MB/sec
	Difference: 268800 (233%)

Texel Rate

The Radeon R9 390 8G should be a lot (about 433%) faster with regards to texture filtering than the Radeon HD 4870 2GB. (explain)

Radeon R9 390 8G		160000 Mtexels/sec
Radeon HD 4870 2GB		30000 Mtexels/sec
	Difference: 130000 (433%)

Pixel Rate

If using high levels of AA is important to you, then the Radeon R9 390 8G is a better choice, by far. (explain)

Radeon R9 390 8G		64000 Mpixels/sec
Radeon HD 4870 2GB		12000 Mpixels/sec
	Difference: 52000 (433%)

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 maximum amount of information (in units of megabytes per second) that can be transferred past the external memory interface in one second. The number is worked out by multiplying the interface width by its memory clock speed. If the card has DDR type RAM, it must be multiplied by 2 again. If DDR5, multiply by 4 instead. The higher 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 texture map elements (texels) that can be applied per second. This is worked out by multiplying the total number of texture units by the core clock speed of the chip. The higher this number, the better the video card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels processed in one second.

Pixel Rate: Pixel rate is the maximum number of pixels that the graphics chip can possibly record to the local memory in a second - measured in millions of pixels per second. Pixel rate is calculated by multiplying the amount of Render Output Units by the the card's clock speed. ROPs (Raster Operations Pipelines - also sometimes called Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel rate is also dependant on many 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.