Join Us On Facebook

Compare any two graphics cards:
VS

Radeon HD 4870 512MB vs Radeon HD 7850

Intro

The Radeon HD 4870 512MB has a core clock frequency of 750 MHz and a GDDR5 memory speed of 900 MHz. It also makes use of a 256-bit bus, and makes use of a 55 nm design. It is comprised of 800(160x5) SPUs, 40 TAUs, and 16 ROPs.

Compare those specs to the Radeon HD 7850, which uses a 28 nm design. AMD has set the core frequency at 860 MHz. The GDDR5 RAM runs at a frequency of 1200 MHz on this specific model. It features 1024 SPUs along with 64 Texture Address Units and 32 ROPs.

(No game benchmarks for this combination yet.)

Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 7850 130 Watts
Radeon HD 4870 512MB 150 Watts
Difference: 20 Watts (15%)

Memory Bandwidth

The Radeon HD 7850 should theoretically perform quite a bit faster than the Radeon HD 4870 512MB in general. (explain)

Radeon HD 7850 153600 MB/sec
Radeon HD 4870 512MB 115200 MB/sec
Difference: 38400 (33%)

Texel Rate

The Radeon HD 7850 should be a lot (approximately 83%) faster with regards to texture filtering than the Radeon HD 4870 512MB. (explain)

Radeon HD 7850 55040 Mtexels/sec
Radeon HD 4870 512MB 30000 Mtexels/sec
Difference: 25040 (83%)

Pixel Rate

If running with high levels of AA is important to you, then the Radeon HD 7850 is a better choice, and very much so. (explain)

Radeon HD 7850 27520 Mpixels/sec
Radeon HD 4870 512MB 12000 Mpixels/sec
Difference: 15520 (129%)

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

Radeon HD 4870 512MB

Amazon.com

Radeon HD 7850

Amazon.com

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

Model Radeon HD 4870 512MB Radeon HD 7850
Manufacturer AMD AMD
Year Jun 25, 2008 March 2012
Code Name RV770 XT Pitcairn Pro
Fab Process 55 nm 28 nm
Bus PCIe 2.0 x16 PCIe 3.0 x16
Memory 512 MB 2048 MB
Core Speed 750 MHz 860 MHz
Shader Speed N/A MHz (N/A) MHz
Memory Speed 900 MHz (3600 MHz effective) 1200 MHz (4800 MHz effective)
Unified Shaders 800(160x5) 1024
Texture Mapping Units 40 64
Render Output Units 16 32
Bus Type GDDR5 GDDR5
Bus Width 256-bit 256-bit
DirectX Version DirectX 10.1 DirectX 11.1
OpenGL Version OpenGL 3.0 OpenGL 4.2
Power (Max TDP) 150 watts 130 watts
Shader Model 4.1 5.0
Bandwidth 115200 MB/sec 153600 MB/sec
Texel Rate 30000 Mtexels/sec 55040 Mtexels/sec
Pixel Rate 12000 Mpixels/sec 27520 Mpixels/sec

Memory Bandwidth: Memory bandwidth is the max amount of information (in units of MB per second) that can be moved across the external memory interface in a second. It's calculated by multiplying the card's bus width by its memory clock speed. In the case of DDR type RAM, it should be multiplied by 2 once again. If DDR5, multiply by ANOTHER 2x. The better 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 can be applied per second. This is calculated by multiplying the total amount of texture units by the core clock speed of the chip. The higher this number, the better the card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels applied per second.

Pixel Rate: Pixel rate is the maximum number of pixels the graphics card can possibly write to the local memory in one second - measured in millions of pixels per second. The figure is calculated by multiplying the amount of ROPs by the the core speed of the card. ROPs (Raster Operations Pipelines - sometimes also referred to as Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel rate is also dependant on lots of other factors, most notably the memory bandwidth of the card - the lower the bandwidth is, the lower the ability to reach the max fill rate.

Comments

Be the first to leave a comment!

Your email address will not be published.


You may use these HTML tags and attributes: <a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <strike> <strong>

WP-SpamFree by Pole Position Marketing