Getting the Best out of an Ivy Bridge HTPC: Windows 8, madVR and More..
by Ganesh T S on January 20, 2013 3:00 PM EST- Posted in
- Home Theater
- Intel
- HTPC
- Ivy Bridge
- Windows 8
- Passive Cooling
HTPC Decoding and Rendering Benchmarks: EVR / EVR-CP
In our Ivy Bridge HTPC review, we had covered the CPU / GPU utilization during playback of various types of clips. In the Vision3D 252B review, we had graphs of CPU and GPU loading with various renderers and codecs. Unfortunately, AMD doesn't provide similar data / sensors for use with their APUs. Hence, we had to resort to power consumed at the wall along with GPU loading in the Trinity HTPC review. In order to keep benchmarking consistent across all HTPC reviews, we started adopting the Trinity HTPC review methodology starting with the review of the ASRock Vision HT.
The tables below present the results of running our HTPC rendering benchmark samples through various decoders when using the Enhanced Video Renderer / Enhanced Video Renderer (Custom Presenter) (EVR / EVR-CP). Entries in bold indicate that there were dropped frames which indicate that the unit wasn't up to the task for those types of streams. Fortunately, none of the streams presented any problem to the system and there were no dropped frames. The recorded values include the GPU loading and power consumed by the system at the wall when playing back the streams using MPC-HC v1.6.5.6366 and LAV Filters 0.54.
Enhanced Video Renderer (EVR)
The Enhanced Video Renderer is the default renderer made available by Windows 8. It is a lean renderer in terms of usage of system resources since most of the aspects are offloaded to the GPU drivers directly. EVR is mostly used in conjunction with native DXVA2 decoding.
| LAV Video Decoder (DXVA2 Native) + EVR | ||
| Stream | GPU Usage % | Power Consumption |
| 480i60 MPEG-2 | 24.05 | 35.04 |
| 576i50 H.264 | 21.38 | 36.06 |
| 720p60 H.264 | 26.13 | 36.6 |
| 1080i60 H.264 | 28.9 | 39.95 |
| 1080i60 MPEG-2 | 28.19 | 37.06 |
| 1080i60 VC-1 | 31.23 | 45.57 |
| 1080p60 H.264 | 30.11 | 37.09 |
The GPU is not taxed much by the EVR despite hardware decoding also taking place. Deinterlacing and other post processing aspects were left at the default settings in the Intel HD Graphics Control Panel (and these are applicable when EVR is chosen as the renderer)
Enhanced Video Renderer - Custom Presenter (EVR-CP)
EVR-CP is the default renderer used by MPC-HC. It is usually used in conjunction with MPC-HC's video decoders, some of which are DXVA-enabled. However, for our tests, we used the DXVA2 mode provided by the LAV Video Decoder.
| LAV Video Decoder (DXVA2 Native) + EVR-CP | ||
| Stream | GPU Usage % | Power Consumption |
| 480i60 MPEG-2 | 26.69 | 38.78 |
| 576i50 H.264 | 24.43 | 37.88 |
| 720p60 H.264 | 32.76 | 40.4 |
| 1080i60 H.264 | 40.16 | 42.02 |
| 1080i60 MPEG-2 | 39.75 | 41.62 |
| 1080i60 VC-1 | 40.99 | 48.45 |
| 1080p60 H.264 | 41.33 | 42 |
In addition to DXVA2 Native, we also used the QuickSync decoder developed by Eric Gur (an Intel applications engineer) and made available to the open source community. It makes use of the specialized decoder blocks available as part of the QuickSync engine in the GPU.
| LAV Video Decoder (QuickSync / DXVA2 Copy-Back) + EVR-CP | ||
| Stream | GPU Usage % | Power Consumption |
| 480i60 MPEG-2 | 27.16 | 38.42 |
| 576i50 H.264 | 25.26 | 38.05 |
| 720p60 H.264 | 36.84 | 41.6 |
| 1080i60 H.264 | 44.2 | 43.41 |
| 1080i60 MPEG-2 | 44.32 | 43.02 |
| 1080i60 VC-1 | 43.56 | 43.26 |
| 1080p60 H.264 | 48.28 | 45.13 |
In general, using the QuickSync decoder results in a higher power consumption because the decoded frames are copied back to the DRAM before being sent to the renderer. Using native DXVA decoding, the frames are directly passed to the renderer without the copy-back step. The odd-man out in the power numbers is the interlaced VC-1 clip, where QuickSync decoding is around 5W more efficient compared to 'native DXVA2'. This is because there is currently no support in the open source native DXVA2 decoders for interlaced VC-1, and hence, it is done in software [Clarification: This restriction is only on Intel GPUs. On both AMD and NVIDIA cards, DXVA2 native decode acceleration is supported for all VC-1 streams]. On the other hand, the QuickSync decoder is able to handle it with the VC-1 bitstream decoder in the GPU.
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Hardcore69 - Sunday, January 20, 2013 - link
A lot of that GPU accelerated DirectX 11.1 stuff is used way more in the Modern UI than the deskto. And where were the power figures for the desktop version of the apps?ganeshts - Sunday, January 20, 2013 - link
Which apps are you talking about in particular?The Netflix app is the only 'Metro-specific' app that we installed. For comparison, we have power figures for Silverlight and Windows 8 too (if that is what you mean by desktop version of the Netflix app).
Everything else was the desktop version.
mavere - Sunday, January 20, 2013 - link
Is it possible to analyze where the Windows 8 power savings are coming from? In a couple tests, the benefits were equal to the entire TDP of some systems, and you'd think Microsoft would have advertised that aspect of Win8 more.I think I speak for most enthusiasts here when I say that the why and how is often more interesting than the what. :D
ganeshts - Tuesday, January 22, 2013 - link
I think a lot of that has to do with avoiding CPU loading (Silverlight), fully functional GPU accelerated decoding (again, not through Slverlight) and possibly DRM is handled through specialized CPU instructions instead of as a Silverlight component.The power differences seem to be non-existent in older systems as per other commenters, but, on modern CPUs / GPUs, it is very evident. So, I suspect a lot has to do with the updates made in the CPUs and GPUs in the last couple of years
Midgetsaw - Sunday, January 20, 2013 - link
This all very well and good but for me a htpc isn't any good without a tv tuner and windows 8 doesnt actually have media center. you have to contact ms to acquire it which is bs, all you have built is a glorified yt player, which you could have probably done with linux.lotharamious - Sunday, January 20, 2013 - link
Do you have Windows 8 Pro? I'd bet you do.Free upgrade from Windows 8 Pro to Windows 8 Pro with Media Center until January 31.
Go here:
http://windows.microsoft.com/en-US/windows-8/featu...
Give them a valid email address and enter the key they give you. Done. Windows 8 with Media Center.
So difficult to "contact ms", my ass. You just want an excuse to hate. I understand, many are like you.
Cygni - Monday, January 21, 2013 - link
Ah yes, finally I can pay to upgrade my OS to a less usable HTPC version, then either jump through hoops (if its the next week and a half )or PAY EXTRA to restore completely un-upgraded functionality that came free with the version I upgraded from.Oh thank you Microsoft, you're truly a gleaming light.
euler007 - Monday, January 21, 2013 - link
I guess free isn't good enough for you. Should they e-mail you a check to earn your anonumous forum support?Golgatha - Monday, January 21, 2013 - link
My time spent "upgrading" isn't free. Nor do I wish to experiment with Windows 8 further after already being maddened by it's ridiculous (for the desktop anyway) UI. I did try it for a few days and then I imaged back to my Win7 install. I like it better and all my programs work with it without issue.lexluthermiester - Monday, January 21, 2013 - link
There are a great many of us who feel your pain. I gave The Consumer Preview a shot and I kinda warmed up to it. The Release Preview ruined that warmth. And and fairness, I gave the retail release a solid month before washing my hands of it. I work for one of the few remaining brick and mortar tech shops in my area and we had a meeting with the owners a couple weeks ago. We were all prepared to tell them that we were unwilling to sell or support Windows 8 any further. To our joy they gave us those very instructions. You should have seen the smiles spreading around the room. And we are not the only ones snubbing 8. Three other shops in this area are doing the same. It was left to me to inform the MS reps of the news. Funny thing, when I did they weren't at all surprised. They didn't argue or try to talk us out of it. They simply said they'd be happy to continue supplying us with 7. I asked one of them why they didn't put up more of an objection. He answer said it all; "You're not the only company to take this position. We know that 8 is not well received or liked". When Microsoft's own reps are talking like that you just KNOW something's wrong. I think I'll leave it at that.