Radeon HD 6770 1GB vs Radeon R9 390X 8G

Intro

Compare that to the Radeon R9 390X 8G, which has a clock frequency of 1050 MHz and a GDDR5 memory frequency of 1500 MHz. It also features a 512-bit memory bus, and makes use of a 28 nm design. It is made up of 2816 SPUs, 176 Texture Address Units, and 64 Raster Operation Units.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 6770 1GB		108 Watts
Radeon R9 390X 8G		275 Watts
	Difference: 167 Watts (155%)

Memory Bandwidth

In theory, the Radeon R9 390X 8G should be 471% quicker than the Radeon HD 6770 1GB in general, because of its greater data rate. (explain)

Radeon R9 390X 8G		384000 MB/sec
Radeon HD 6770 1GB		67200 MB/sec
	Difference: 316800 (471%)

Texel Rate

The Radeon R9 390X 8G is a lot (more or less 413%) better at AF than the Radeon HD 6770 1GB. (explain)

Radeon R9 390X 8G		184800 Mtexels/sec
Radeon HD 6770 1GB		36000 Mtexels/sec
	Difference: 148800 (413%)

Pixel Rate

If running with a high resolution is important to you, then the Radeon R9 390X 8G is superior to the Radeon HD 6770 1GB, by a large margin. (explain)

Radeon R9 390X 8G		67200 Mpixels/sec
Radeon HD 6770 1GB		14400 Mpixels/sec
	Difference: 52800 (367%)

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 max amount of information (measured in MB per second) that can be transported over the external memory interface in a second. It's calculated by multiplying the card's interface width by its memory clock speed. If the card has DDR RAM, it must be multiplied by 2 once again. If it uses DDR5, multiply by 4 instead. The better the card's memory bandwidth, the faster 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 amount of texture map elements (texels) that can be processed 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 the texel rate, the better the video card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels in a second.

Pixel Rate: Pixel rate is the maximum amount of pixels the video card can possibly record to the local memory in one second - measured in millions of pixels per second. The figure is worked out by multiplying the amount of ROPs by the the core clock speed. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel rate is also dependant on many other factors, most notably the memory bandwidth of the card - the lower the memory bandwidth is, the lower the ability to reach the max fill rate.