GeForce GTX 650 vs Radeon HD 4890 1GB

Intro

Compare those specs to the Radeon HD 4890 1GB, which has a core clock speed of 1000 MHz and a GDDR5 memory speed of 975 MHz. It also uses a 256-bit memory bus, and makes use of a 55 nm design. It is comprised of 800(160x5) SPUs, 40 TAUs, and 16 ROPs.

Display Graphs

Hide Graphs

Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

GeForce GTX 650		64 Watts
Radeon HD 4890 1GB		190 Watts
	Difference: 126 Watts (197%)

Memory Bandwidth

In theory, the Radeon HD 4890 1GB should be 56% faster than the GeForce GTX 650 in general, because of its higher data rate. (explain)

Radeon HD 4890 1GB		124800 MB/sec
GeForce GTX 650		80000 MB/sec
	Difference: 44800 (56%)

Texel Rate

The Radeon HD 4890 1GB is just a bit (approximately 18%) faster with regards to AF than the GeForce GTX 650. (explain)

Radeon HD 4890 1GB		40000 Mtexels/sec
GeForce GTX 650		33856 Mtexels/sec
	Difference: 6144 (18%)

Pixel Rate

The GeForce GTX 650 should be just a bit (approximately 6%) better at FSAA than the Radeon HD 4890 1GB, and will be capable of handling higher resolutions more effectively. (explain)

GeForce GTX 650		16928 Mpixels/sec
Radeon HD 4890 1GB		16000 Mpixels/sec
	Difference: 928 (6%)

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 information (measured in MB per second) that can be transported past the external memory interface within a second. The number is calculated by multiplying the bus width by its memory speed. If it uses DDR type RAM, it must be multiplied by 2 once again. If DDR5, multiply by 4 instead. The higher the memory bandwidth, the better the card will be in general. It especially helps with AA, HDR and higher screen resolutions.

Texel Rate: Texel rate is the maximum texture map elements (texels) that are applied in one second. This is calculated by multiplying the total amount of texture units by the core clock 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 most pixels that the graphics chip could possibly write to the local memory in a second - measured in millions of pixels per second. The figure is worked out by multiplying the amount of ROPs by the the core speed of the card. ROPs (Raster Operations Pipelines - also sometimes called Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel output rate also depends on many other factors, most notably the memory bandwidth of the card - the lower the memory bandwidth is, the lower the potential to get to the max fill rate.