AMD Radeon HD 7750 & Radeon HD 7770 GHz Edition Review: Evading The Price/Performance Curve
by Ryan Smith & Ganesh T S on February 15, 2012 12:01 AM EST- Posted in
- GPUs
- AMD
- HTPC
- GCN
- Radeon HD 7000
Custom Refresh Rates with AMD 7750
One of the drawbacks of the GPUs built into the Intel CPUs was the lack of a 23.976 Hz refresh rate to match the source frame rate of many videos. Combined with the lack of reliable support for open source software, this has often pushed users to opt for a discrete HTPC GPU. Ideally, a GPU should be capable of the following refresh rates at the minimum:
- 23.976 Hz
- 24 Hz
- 25 Hz
- 29.97 Hz
- 30 Hz
- 50 Hz
- 59.94 Hz
- 60 Hz
Some users demand integral multiples of 23.976 / 24 Hz because they result in a smoother desktop experience, while also making sure that the source and display refresh rates are still matched without repeated or dropped frames.
With the Sony Bravia KDL46EX720 (the new display in our HTPC testbed) being capable of PAL refresh rates (despite not exposing it in the EDID), we were able to test out almost all the above mentioned refresh rates. The only exception was 60 Hz (which definitely works well in the usual desktop mode, but, was one for which we were unable to obtain a sample file with a matching frame rate).
Using madVR, we were able to judge how often a frame would get repeated or dropped in the renderer due to the mismatched refresh rate and frame rate. With the 23.976 fps sample, we were looking at more than 15 minutes before a dropped frame, while, for the 24 fps sample, we were looking at more than a hour before a frame repeat.
By default, modes not reported in the EDID were not available in the CCC settings. However, it was quite straightforward to display and choose the refresh rates not supported by the monitor in its Windows settings. Some of the other 'native refresh rates' we tested are reproduced below:
AMD's refresh rate matching feature works pretty well most of the time, but it could be made better by giving the user more control over the various timing aspects (maybe in an 'Advanced' hidden menu similar to what is done by NVIDIA). This could be useful for consumers who don't want to put up with frame drops / repeats even once every 20 minutes or so.
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faizoff - Wednesday, February 15, 2012 - link
I thought the 7770 would outperform the 6850 at least. Great review.sigmatau - Wednesday, February 15, 2012 - link
For AMD cards, you look at the second number to indicate performance. An 8 series card like in the 6850 usualy performs as well or slightly better than a next generation 7 series card like the 7770.The 3rd number also indicates performance, but not nearly as much as the second number.
TerdFerguson - Wednesday, February 15, 2012 - link
er, not really. A 58xx is faster than a 68xx.sigmatau - Wednesday, February 15, 2012 - link
The 68xx series introduced an anomaly in the formula. But generaly what I stated is true.CeriseCogburn - Saturday, March 10, 2012 - link
The anomaly here is the NVIDIA Gtx460 SMOKES the 7770 on everything, in every test, and costs 33% less.I see the crazed fan base cannot bring themselves to say it.
I'll say it - 19 pages unsaid, over a long time.
THE NVIDIA GTX460 SMOKES THIS CARD RO DEATH, AND THERE'S MORE OF THOSE ON NEWEGG FOR LESS MONEY THAN THE 7770.
Spunjji - Thursday, June 21, 2012 - link
My word you are tiresome.nissangtr786 - Thursday, July 5, 2012 - link
Using your logic a gtx 580 smoke the gtx 460.The reason why 7770 costs a bit is because its new technology, power consumption goes down quite a bit. Compare the card to same power consumption of new generation card maybe a 7870 and the 7870 will smoke the gtx 460.
perferformance per watt 7770m smokes the gtx 460.
lambchowder - Thursday, November 1, 2012 - link
you seriously need to stop posting. everything you post comes off as rabid nvidia fanatic, because you evidently are one, and you seem to camp outside these benchmarks to say the same thing everytime!! "this thing SMOKES~~~~!! the 7770!!! thats all i look at are the frame rates!!! i dont take anything else into consideration cause im an nvidia superfan"Beararam1 - Thursday, February 16, 2012 - link
Really? I thought the 6870>5850. No?CeriseCogburn - Saturday, March 10, 2012 - link
This 7k series needs some www.verdetrol.com--
LOL - How low can you go amd ?
Seems like more firings and cullings are in the works - or perhaps they already dragged the cat in and are now stuck with perverts.