Discrete HTPC GPU Shootoutby Ganesh T S on June 12, 2011 10:30 PM EST
The popularity of Intel's HD Graphics amongst HTPC enthusiasts and the success of the AMD APUs seem to indicate that the days of the discrete HTPC GPU are numbered. However, for those with legacy systems, a discrete HTPC GPU will probably be the only way to enable hardware accelerated HD playback. In the meanwhile, discrete HTPC GPUs also aim to offer more video post processing capabilities.
In this context, both AMD and NVIDIA have been serving the market with their low end GPUs. These GPUs are preferable for HTPC scenarios due to their low power consumption and ability to be passively cooled. Today, we will be taking a look at four GPUs for which passively cooled solutions exist in the market. From AMD's side, we have the 6450 and 6570, while the GT 430 and GT 520 make up the numbers from the NVIDIA side.
Gaming benchmarks are not of much interest to the HTPC user interested in a passively cooled solution. Instead of focusing on that aspect, we will evaluate factors relevant to the AV experience. After taking a look at the paper specifications of the candidates, we will describe our evaluation testbed.
We will start off the hands-on evaluation with a presentation of the HQV benchmarks. This provides the first differentiating factor.
While almost all cards (including the integrated graphics on CPUs) are able to playback HD videos with some sort of acceleration, videophiles are more demanding. They want to customize the display refresh rate to match the source frame rate of the video being played. Casual HTPC users may not recognize the subtle issues created by mismatched refresh rates. However, improper deinterlacing may lead to highly noticeable issues. We will devote a couple of sections to see how the cards handle custom refresh rates and fare at deinterlacing.
After this, we will proceed to identify a benchmark for evaluating HTPC GPUs. This benchmark gives us an idea of how fast the GPUs can decode the supported codecs, and whether faster decoding implies more time for post processing. We will see one of the cards having insane decoding speeds, and try to find out why.
Over the last few months, we have also been keeping track of some exciting open source software in the HTPC area. Aiming to simplify the player setup and also take advantage of as many features of your GPU as possible, we believe these are very close to being ready for prime time. We will have a couple of sections covering the setup and usage of these tools.
Without further ado, let us go forward and take a look at the contenders.
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enki - Monday, June 13, 2011 - linkHow about a short conclusion section for those who just use a Windows 7 box with a Ceton tuner card to watch hdtv in Windows Media Center? (i.e. will just be playing back WTV files recorded directly on the box)
What provides the best quality output?
What can stream better then stereo over HDMI? On my old 3400 ATI card it either streams the Dolby Digital directly (the computer doesn't do any processing of the audio) or can output stereo (doesn't think there can be more then 2 speakers connected)
BernardP - Monday, June 13, 2011 - linkThe inability to create and scale custom resolutions within AMD graphics drivers is, for me, a deal-breaker that keeps me from even considering AMD graphics. It will also keep me from Llano, Trinity and future AMD Fusion APU's. I'll stay with NVidia as long as they keep allowing for custom resolutions.
My older eyes are grateful for the custom 1536 X 960 desktop resolution on my 24 inch 16:10 monitor. I couldn't create this resolution with AMD graphics drivers.
bobbozzo - Tuesday, June 14, 2011 - linkIn your case, you should just increase the size of the fonts and widgets instead of lowering the screen res.
Assimilator87 - Tuesday, June 14, 2011 - linkI wish there was a section dedicated to the silent stream bug. I have a GTX 470 hooked up to an Onkyo TX-SR805 and this issue is driving me insane. For instance, does this issue only plague certain cards or do all nVidia suffer from it? I was hoping the latest WHQL driver (275.33) would fix this, but sadly, no. Otherwise, the article was amazing and I'll definitely have to check out LAV Splitter.
ganeshts - Tuesday, June 14, 2011 - linkThe problem with the silent stream bug is that one driver version has it, the next one doesn't and then the next release brings it back. It is hard to pinpoint where the issue is.
Amongst our candidates, even with the same driver release, the GT 520 had the bug, but the GT 430 didn't. I am quite confident that the GT 520 issue will get resolved in a future update, but then, I can just hope that it doesn't break the GT 430.
JoeHH - Tuesday, June 14, 2011 - linkThis is simply one of the best articles I have ever seen about HTPC. Congrats Ganesh and thank you. Very informative and useful.
bobbozzo - Tuesday, June 14, 2011 - linkHi, Can you please compare hardware de-intelacing, etc., vs software?
e.g. many players/codecs can do de-interlacing, de-noise, etc. in software, using the CPU.
How does this compare with a hardware implementation?
ganeshts - Tuesday, June 14, 2011 - linkThis is a good suggestion. Let me try that out in the next HTPC / GPU piece.
CiNcH - Wednesday, June 15, 2011 - linkHey guys,
here is how I understand the refresh rate issue. It does not matter weather it is 0.005 Hz off. You can't calculate frame drops/repeats from that. In DirectShow, frames are scheduled with the graph reference clock. So the real problem is how much the clock which the VSync is based on and the reference clock in the DirectShow graph drift from each other. And here comes ReClock into play. It derives the DirectShow graph clock from the VSync, i.e. synchronizes the two. So it does not matter weather your VSync is off as long as playback speed is adjusted accordingly. A problem here is synchronizing audio which is not too easy if you bitstream it...
NikosD - Thursday, June 16, 2011 - linkNice guide but you missed something.
It's called PotPlayer, it's free and has built-in almost everything.
CPU & DXVA (partial, full) codecs and splitters for almost every container and every video file out there.
The same is true for audio, too.
It has even Pass through (S/PDIF, HDMI) for AC3/TrueHD/DTS, DTS-HD. Only EAC3 is not working.
It has also support for madVR and a unique DXVA-renderless mode which combines DXVA & madVR!
I think it's close to perfect!
BTW, in the article says that there is no free audio decoder for DTS, DTS-HD.
That's not correct.
FFDShow is capable of decoding and pass through (S/PDIF, HDMI) both DTS and DTS-HD.
And PotPlayer of course!