Video Post-Processing: GPU Loading

We saw in our coverage of discrete HTPC GPUs last year that noise reduction loaded up the GPU, and as such, was even disabled in the low end GPUs for want of shader resources. Starting with this review, we are planning to tabulate GPU usage under various post processing scenarios instead of running decoder benchmarks. GPU-Z gives us the necessary data for this purpose.

A 1080i60 H.264 clip (same as the one used in the discrete HTPC GPU article last year) was decoded with the LAV Video Decoder (DXVA2 Copy-Back mode) using EVR-CP as a renderer in GraphStudio Next's Decoder Performance section. Various post-processing options were turned on and off in CCC and the GPU usage recorded in each case.

Video Post Processing GPU Usage: 1080i60 H.264
AMD Radeon HD 7750 (1GB GDDR5) / Catalyst 12.1
LAV Video Decoder DXVA2 (Copy-Back) v0.46 / EVR-CP
Post Processing Algorithm GPU Load
No Video Post Processing 19%
Vector Adaptive Deinterlacing + Pulldown Detection 25%
Edge Enhancement 22%
Noise Reduction 48%
Dynamic Contrast and Colour 25%
All Post Processing / 'Enforce Smooth Video Playback' Disabled 62%

We also put some Full SBS / Full TAB 3D clips (which are basically 2 x HD resolution) through the same process. Those progressive clips resulted in around 70% of the GPU being loaded with all the post processing steps enabled.

It is not yet possible to use the madVR renderer from within GraphStudio Next, but, in future HTPC / HTPC GPU reviews, you can expect to find similar benchmarking with the madVR renderer (now that it is possible to use madVR along with hardware accelerated decode for AMD GPUs also). That said, we see that up to 62% of the GPU is loaded using just EVR-CP. It is not clear how much room is left for madVR processing, and we hope to address that question in future reviews.

Custom Refresh Rates Miscellaneous HTPC Aspects
Comments Locked

155 Comments

View All Comments

  • rdh - Wednesday, February 15, 2012 - link

    Bingo. But your numbers look at if you were to want to buy today. You might have bought the 5750 or 5770 at a significantly lower cost during a sale in the past 2.5 years. So individual price comparisons may be different than today's prices.

    IN ADDITION: the 7770 and 7750 require about 3% less power and produce frame rates about 10% higher than their 57xx counterparts. This is after the 57xx have been out for nearly TWO AND HALF YEARS. I purchased both (the 5750 for one system at $65 and the 5770 for another at $99) about 6 months after introduction. Two years later, there is no compelling reason for me to upgrade. That means AMD is only going to be selling these to new desktop purchasers.... a quickly shrinking market. This cannot be good for AMD.
  • CeriseCogburn - Saturday, March 10, 2012 - link

    Since fps is your only metric, itself being a murky and disturbed error filled easily biased mess based upon game set, driver cheating, resolutions, and in game settings chosen, the entire price/perf chart is EPIC FAIL.
    When your drivers crash, when your game doesn't work, when new games don't work for weeks and months, when dual card drivers are absent, when features like PhysX are no can do - NONE OF IT IS ACCOUNTED FOR....
    ---
    Obviously all amd has to do is follow the simpleton idiot fps/per dollar formula for all the stuck cursor gsod fanboys to bloviate and screech they saved 20 cents... then the amd forum masters casn continue to lock them out, lock user problem threads, and smart off that "it's works for them on their eyefinity setup theya re starig at right now"...
    ---
    When a crazed, worship filled, religious zealoutry claims the heavens have opened on the cheap and the devil competition has lost all, beware...
    Oh.. wait... sorry talking to the wrong person...
  • Roland00Address - Wednesday, February 15, 2012 - link

    I am curious how high these cards will go before they hit the powertune limits.
  • Ryan Smith - Wednesday, February 15, 2012 - link

    I'm still writing up an addendum, but here's what I have for the 7770.

    Ref 7770: 1125MHz core, 4.8GHz memory
    XFX 7770: No meaningful overclock on top of XFX's factory overclock. Crashed at 1160MHz core

    As for performance, basically look at the XFX card.
  • Roland00Address - Wednesday, February 15, 2012 - link

    Personally I find that the more interesting card
  • Ryan Smith - Wednesday, February 15, 2012 - link

    We didn't do any overclocking tests on the 7750. It was necessary to quickly test it in order to be able to ship it to Ganesh for HTPC testing.
  • DarkSynergyt - Wednesday, February 15, 2012 - link

    Might be a stupid question but can the 7750 output audio over HDMI? I'm in the process of building an HTPC and this is the final piece to the build.
  • evilspoons - Wednesday, February 15, 2012 - link

    My 6570 can and I'm pretty sure they said in the review that it has all the same features as previous generations for video features.
  • ganeshts - Wednesday, February 15, 2012 - link

    Yes, it does. With full bitstreaming options too (even WMA Pro). 7.1 channel LPCM support is also there. No worries. (Of course, hot plugging [ say, moving from a direct monitor connection to an AV receiver input ] causes the audio output to act crazy, but that is the case with every card. Reboot fixes the issue)
  • evilspoons - Wednesday, February 15, 2012 - link

    This really drives home how obsolete my GTX 285 is. The 7770 has about equivalent performance and uses *130 watts* less.

    I need a new video card, but I want to see what Nvidia has for us next - I'm not a fanboy (in spite of all my gaming cards since the 3dfx Voodoo 3 being Nvidia), I'm just genuinely hoping for either some competition to drive prices down or something better to blow us away. Come on guys, get a move on already!

Log in

Don't have an account? Sign up now