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.

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  • PatrickSteamboat - Wednesday, February 15, 2012 - link

    Will there be any testing on Cape Verde's Crossfire scalability in the near future? I'm really interested to see if dual 7750s can fill the gap between it and the 6950. Unlocking a hidden, low power 6900 variant, the missing 6930, without having to match and compare more than three SKUs sounds too good to be true.
  • Roland00Address - Wednesday, February 15, 2012 - link

    7750s can't do crossfire since they do not have a crossfire bridge.
    7770s can do crossfire since they have a single crossfire bridge (can't do trifire though).
  • PatrickSteamboat - Thursday, February 16, 2012 - link

    power, and cementing its position as the replacement for the 6670 there isn’t a CrossFire connector on the card


    Can't believe I missed... anyways, thanks for that.

    I found a preliminary benchmark with dual 7770s. Numbers look great so far, but at $318 for two, I'll be waiting until I can have both for less than $279. One now @MSRP, the second discounted once Kepler is out.
  • mczak - Thursday, February 16, 2012 - link

    That isn't true. 7750 don't have a crossfire connector but they can do crossfire just fine, by transferring the data over the pcie bus.
    According to techpowerup benchmarks which tested that there's not even really a performance hit due to that (though they used a board with 2x16 pcie lanes, albeit only pcie 2.0, so should be similar to ivy bridge lga1155 which will have 2x8 pcie 3.0, and it might be worse on sandy bridge lga1155 which only has 2x8 pcie 2.0), though they say there were some stability issues, which certainly are driver fixable.
    I usually question the viability of low-end CF setups however, I think you'd be far better off with one HD7800 card instead (you shouldn't need to wait that long for it after all).
  • Belard - Thursday, February 16, 2012 - link

    Its been almost 4 years since the ATI 4850 was released. Within about 6~8 months of being on the market, it became a $100~110 card.

    The NEW 7750 is also a $100~110 and from looking at these reviews, it performs no better than a four year old gaming card that sold for $100.
  • Menoetios - Thursday, February 16, 2012 - link

    Nvidia is as much to blame for the lack of shift in the price/performance curve as AMD. That's just the nature of competition. If you look at the 7770 and 7750 pricing compared to what Nvidia currently has available, it falls right in line. AMD doesn't care that you buy a 7770 or a 6850; with the former they'll make a nice margin, with the latter it'll help clear out the channel. They only care that you buy one of their products, and their products are priced just fine to that end. With only 123 mm2 die size (it's quite tiny), the 77** cards have a lot of room to get cheaper when Kepler is released. And I hope Kepler is REALLY good, because that's when we'll see the true price/performance shift.
  • chizow - Thursday, February 16, 2012 - link

    How so? Nvidia is not the one pricing their next-gen parts based on last-gen performance and pricing, AMD is. If Nvidia does that with Kepler, then you they share in equal blame. But AMD had the chance to fire the first salvo this generation and they whiffed, badly, on all 3 volleys now (7970, 7950 and now 7770).
  • Menoetios - Thursday, February 16, 2012 - link

    AMD have set their prices according to what's available on the market from Nvidia.
  • chizow - Friday, February 17, 2012 - link

    And that's exactly the problem! They're pricing new 28nm next-gen parts based on old 40nm last-gen price and performance levels. Nvidia's pricing was justified 14 months ago because the performance was there. It would not be satisfactory if they came out with a "new" part tomorrow and priced it the same as their old parts, would it?

    Blame lies squarely on AMD for this because they set the pricing on their parts and they were first to market. Look at it historically over the last 2-3 major generations, never once has Nvidia done this with a new architecture (not refresh) in terms of moving the performance bar so little while expecting the same top of the line premium pricing.
  • Hellbinder - Thursday, February 16, 2012 - link

    Ok, Anand continues to amaze.. he/they are either dumber than a box of rocks or intentionally biased against AMD and simply looking for any excuse to skewer them. Personally i lean towards option number 1.

    The author of this review has completely buffooned the entire thing by getting the basic workings of AMD numbering & performance scaling WRONG.

    yes the naming convention changed. but not in the way anand seems to think. This should be no brainier information for a site like this.

    Top 7900 next 7800 next 7700 next 7500 next 7400 and so on.

    The 6000 series was identical

    Top 6800 next 6800 next 6700 next 6500 next 6400 and so on

    the older models were different.

    IF you want to compare apples to apples you compare the 6700 series to this series. The 6800 series is an entire tier above this card and should outperform it.

    This site needs to get its crap together because nearly every other tech site makes this one look foolish, because they are foolish. or fire this reviewer and the editor and get some people who know what the hell they are talking about.

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