Compare any two graphics cards:
VS

Radeon HD 4790 vs Radeon HD 6850

Intro

The Radeon HD 4790 comes with a clock frequency of 600 MHz and a GDDR5 memory speed of 800 MHz. It also makes use of a 256-bit bus, and makes use of a 55 nm design. It is made up of 640(128x5) SPUs, 32 Texture Address Units, and 16 ROPs.

Compare those specifications to the Radeon HD 6850, which features a core clock frequency of 775 MHz and a GDDR5 memory speed of 1000 MHz. It also features a 256-bit memory bus, and makes use of a 40 nm design. It is comprised of 960 SPUs, 48 Texture Address Units, and 32 Raster Operation Units.

Display Graphs

Hide Graphs

Power Usage and Theoretical Benchmarks

Memory Bandwidth

Performance-wise, the Radeon HD 6850 should in theory be quite a bit superior to the Radeon HD 4790 overall. (explain)

Radeon HD 6850 128000 MB/sec
Radeon HD 4790 102400 MB/sec
Difference: 25600 (25%)

Texel Rate

The Radeon HD 6850 will be quite a bit (about 94%) faster with regards to AF than the Radeon HD 4790. (explain)

Radeon HD 6850 37200 Mtexels/sec
Radeon HD 4790 19200 Mtexels/sec
Difference: 18000 (94%)

Pixel Rate

The Radeon HD 6850 will be much (about 158%) faster with regards to FSAA than the Radeon HD 4790, and also will be able to handle higher resolutions more effectively. (explain)

Radeon HD 6850 24800 Mpixels/sec
Radeon HD 4790 9600 Mpixels/sec
Difference: 15200 (158%)

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

Display Prices

Hide Prices

Radeon HD 4790

Amazon.com

Check prices at:

Radeon HD 6850

Amazon.com

Check prices at:

Please note that the price comparisons are based on search keywords - sometimes it might show cards with very similar names that are not exactly the same as the one chosen in the comparison. We do try to filter out the wrong results as best we can, though.

Specifications

Display Specifications

Hide Specifications

Model Radeon HD 4790 Radeon HD 6850
Manufacturer AMD AMD
Year 2009 October 2010
Code Name RV790 Barts Pro
Memory 512 MB 1024 MB
Core Speed 600 MHz 775 MHz
Memory Speed 3200 MHz 4000 MHz
Power (Max TDP) (Unknown) watts 127 watts
Bandwidth 102400 MB/sec 128000 MB/sec
Texel Rate 19200 Mtexels/sec 37200 Mtexels/sec
Pixel Rate 9600 Mpixels/sec 24800 Mpixels/sec
Unified Shaders 640(128x5) 960
Texture Mapping Units 32 48
Render Output Units 16 32
Bus Type GDDR5 GDDR5
Bus Width 256-bit 256-bit
Fab Process 55 nm 40 nm
Transistors 959 million 1700 million
Bus PCIe 2.0 x16 PCIe x16
DirectX Version DirectX 10.1 DirectX 11
OpenGL Version OpenGL 3.0 OpenGL 4.1

Memory Bandwidth: Bandwidth is the maximum amount of data (measured in megabytes per second) that can be transferred over the external memory interface in a second. It's worked out by multiplying the card's bus width by its memory speed. If the card has DDR type memory, the result should be multiplied by 2 once again. If it uses DDR5, multiply by ANOTHER 2x. The better 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 number of texture map elements (texels) that can be applied in one second. This number is worked out by multiplying the total amount of texture units by the core clock speed of the chip. The higher this number, the better the video card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels in a second.

Pixel Rate: Pixel rate is the most pixels that the graphics chip can possibly write to its local memory per second - measured in millions of pixels per second. The figure is calculated by multiplying the number of colour ROPs by the clock speed of the card. ROPs (Raster Operations Pipelines - also called Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel output rate also depends on many other factors, most notably the memory bandwidth - the lower the memory bandwidth is, the lower the ability to reach the maximum fill rate.

Display Prices

Hide Prices

Radeon HD 4790

Amazon.com

Check prices at:

Radeon HD 6850

Amazon.com

Check prices at:

Please note that the price comparisons are based on search keywords - sometimes it might show cards with very similar names that are not exactly the same as the one chosen in the comparison. We do try to filter out the wrong results as best we can, though.

Comments

Be the first to leave a comment!

Your email address will not be published. Required fields are marked *


*

WordPress Anti Spam by WP-SpamShield