GeForce GTX 950 vs Radeon HD 4890 2GB

Intro

Compare all of that to the Radeon HD 4890 2GB, which features a clock frequency of 1000 MHz and a GDDR5 memory speed of 975 MHz. It also makes use of a 256-bit memory bus, and uses a 55 nm design. It is comprised of 800(160x5) SPUs, 40 Texture Address Units, and 16 ROPs.

Display Graphs

Hide Graphs

Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

GeForce GTX 950		90 Watts
Radeon HD 4890 2GB		190 Watts
	Difference: 100 Watts (111%)

Memory Bandwidth

Performance-wise, the Radeon HD 4890 2GB should theoretically be just a bit superior to the GeForce GTX 950 overall. (explain)

Radeon HD 4890 2GB		124800 MB/sec
GeForce GTX 950		105728 MB/sec
	Difference: 19072 (18%)

Texel Rate

The GeForce GTX 950 should be much (more or less 23%) better at anisotropic filtering than the Radeon HD 4890 2GB. (explain)

GeForce GTX 950		49152 Mtexels/sec
Radeon HD 4890 2GB		40000 Mtexels/sec
	Difference: 9152 (23%)

Pixel Rate

The GeForce GTX 950 is quite a bit (about 105%) better at anti-aliasing than the Radeon HD 4890 2GB, and capable of handling higher resolutions while still performing well. (explain)

GeForce GTX 950		32768 Mpixels/sec
Radeon HD 4890 2GB		16000 Mpixels/sec
	Difference: 16768 (105%)

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 largest amount of data (counted in megabytes per second) that can be transported across the external memory interface within a second. The number is worked out by multiplying the card's interface width by its memory speed. If the card has DDR RAM, it should be multiplied by 2 once again. If it uses DDR5, multiply by 4 instead. The higher the card's memory bandwidth, the better the card will be in general. It especially helps with anti-aliasing, High Dynamic Range and higher screen resolutions.

Texel Rate: Texel rate is the maximum texture map elements (texels) that can be applied in one second. This is worked out by multiplying the total texture units by the core clock speed of the chip. The better this number, the better the video 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 the graphics card could possibly write to its local memory per second - measured in millions of pixels per second. The number is worked out by multiplying the number of colour ROPs by the clock 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 rate also depends on quite a few other factors, most notably the memory bandwidth of the card - the lower the bandwidth is, the lower the ability to get to the max fill rate.