AMD Radeon HD 7750 & HD 7770 Launch Review



Product: AMD Radeon HD 7700 Series
Company: AMD
Author: James Prior
Editor: Charles Oliver
Date: February 14th, 2012

Overclocking, Noise, Power & Filtering

Overclocking

Using MSI Afterburner we were able to adjust voltage on the AMD Radeon HD 7770, but not the 7750.

For the Radeon HD 7770 we were able to increase core engine clock to 1160MHz at 1.37v (an increase of 160MHz and .17v over stock) with memory clock at 1275MHz / 5.1Gbps. For the Radeon HD 7750, we were able to max out AMD Overdrive, and run 900MHz engine clock and 1250MHz / 5Gbps memory clock.

With our new overclock we decided to rerun the 3DMark11 Performance and Extreme tests, to see how the new clock speeds affected the scores:

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The overclock allows the 7770 to outperform the 6850, and the 7750 to beat the 6770.

Next we measured GPU core temperatures at idle and under Kombustor load (30mins each).

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Both cards were quiet and unintrusive in their load cooling performance. The new style coolers are very effective at this form factor and power level.

Our final tests were to examine filtering performance hit:

First, we use Aliens Vs. Predator benchmark at 1920x1080 with 0xAA/high textures/medium shadows/SSAO off/tessellation on/advanced shadows off and varying levels of Anisotropic Filtering, result are average FPS:

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16xAF is a bigger impact on performance on the 7750 (~13%) than on the 7770 (~8.2%)

Next, DiRT 3 at 1920x1080 Ultra preset with varying levels of Anti-Aliasing, including using VECC Enhanced Quality AA modes, AAA, SSAA, EDAA and MLAA; results are average FPS:

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Largely identical hits for the various AA modes and levels, although the 7750 appears to bottom out at 4xSSAA and 4xEDAA.

Last we examine tessellation factor scaling, using Crysis 2 and varying levels of tessellation cap as controlled by VECC:

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Cape Verde is clearly not tessellation stage bound; the bottleneck in this test is shader power.