Radeon HD 4870 X2 vs Radeon R7 250

Intro

Compare that to the Radeon R7 250, which has a core clock frequency of 1000 MHz and a GDDR5 memory speed of 1150 MHz. It also features a 128-bit bus, and makes use of a 28 nm design. It is made up of 384 SPUs, 24 Texture Address Units, and 8 ROPs.

Display Graphs

Hide Graphs

Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon R7 250		65 Watts
Radeon HD 4870 X2		350 Watts
	Difference: 285 Watts (438%)

Memory Bandwidth

In theory, the Radeon HD 4870 X2 should perform a lot faster than the Radeon R7 250 overall. (explain)

Radeon HD 4870 X2		230400 MB/sec
Radeon R7 250		73600 MB/sec
	Difference: 156800 (213%)

Texel Rate

The Radeon HD 4870 X2 is quite a bit (more or less 150%) faster with regards to texture filtering than the Radeon R7 250. (explain)

Radeon HD 4870 X2		60000 Mtexels/sec
Radeon R7 250		24000 Mtexels/sec
	Difference: 36000 (150%)

Pixel Rate

The Radeon HD 4870 X2 should be quite a bit (about 200%) faster with regards to FSAA than the Radeon R7 250, and able to handle higher screen resolutions better. (explain)

Radeon HD 4870 X2		24000 Mpixels/sec
Radeon R7 250		8000 Mpixels/sec
	Difference: 16000 (200%)

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.

One or more cards in this comparison are multi-core. This means that their bandwidth, texel and pixel rates are theoretically doubled - this does not mean the card will actually perform twice as fast, but only that it should in theory be able to. Actual game benchmarks will give a more accurate idea of what it's capable of.

Price Comparison

Specifications

Memory Bandwidth: Memory bandwidth is the largest amount of information (measured in megabytes per second) that can be moved past the external memory interface in a second. It's calculated by multiplying the interface width by its memory speed. If it uses DDR RAM, the result should be multiplied by 2 once again. If it uses DDR5, multiply by ANOTHER 2x. The better the bandwidth is, the faster the card will be in general. It especially helps with AA, High Dynamic Range and high resolutions.

Texel Rate: Texel rate is the maximum texture map elements (texels) that are processed per second. This figure is worked out by multiplying the total 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 per second.

Pixel Rate: Pixel rate is the most pixels the graphics card can possibly write to its local memory in a second - measured in millions of pixels per second. The figure is worked out by multiplying the number of Render Output Units by the clock speed of the card. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel output rate is also dependant on lots of other factors, most notably the memory bandwidth - the lower the bandwidth is, the lower the potential to get to the max fill rate.