In the Intel Ivy Bridge HTPC review, we introduced our video decoding and rendering benchmarking methodology. These benchmarks provide an idea of the capabilities of the system with respect to usage of various video renderers in the Windows environment. Under Microsoft's DirectShow framework, there are a number of options for the video rendering filters. Amongst the native ones, EVR (Enhanced Video Renderer) is preferred. The native EVR mixer uses the DXVA video processing services to deinterlace and mix the video. So, this gurantees that the driver's post processing capabilities (if enabled) get utilized. Users of MPC-HC have EVR-CP (Enhanced Video Renderer - Custom Presenter) as the default. This is an open-source implementation of the interfaces provided by EVR and uses all of the driver's post processing capabilities except for the hardware scaler.

Our Ivy Bridge HTPC review presented CPU and GPU utilization during the playback of various types of clips (different codecs / resolution / interlacing characteristics etc.). We have further refined the methodology by including a 720p60 clip in the list. Also, we have changed the presentation scheme for the results. Comparing CPU usage directly has never been a fool-proof way to identify exactly how much more the system is stressed on a comparative basis (because the CPUs always tend to enter a lower clocked state under low loading conditions). Instead, the power consumed by the CPU package is a better comparison metric. In addition, we have also changed the presentation of the results. Instead of a table with numbers, we have usage graphs.

In this section, we will consider the usage of software decode as well as hardware decode when combined with EVR. As mentioned earlier, LAV Video Decoder was used. It has a native DXVA2 mode as well as a 'None' mode for hardware decoding which defaults to avcodec.

Software Decode with EVR Native DXVA2 with EVR
Software Decode with EVR Native DXVA2 with EVR

Resource Usage Comparison - DXVA2 Hardware Decode vs. Software Decode with EVR

We tested a variety of clips (480i60 MPEG-2, 576i50 H.264, 720p60 H.264, 1080i60 H.264, 1080i60 MPEG-2, 1080i60 VC-1 and 1080p60 H.264) and the observed CPU package power, GPU core loading, GPU memory controller loading, GPU VPU loading and GPU memory loading are presented in the pictures above. You can roll over the mouse on the text at either the top or bottom of the picture to see how the characteristics change. In the case that you wish to download the images for further perusal, the appropriate plots are linked here [ Software Decode with EVR, Native DXVA2 with EVR ].

The results are not surprising. Playback of HD material benefits immensely from hardware decoding. With 1080p60 H.264, software decode takes up more than 50% of the CPU's allowed power consumption. (~19W, when the Core i5-2520M is rated for 35W). The GT 540M's core and memory controller loads are the same for both software and memory decode. However, the VPU gets loaded (almost 85% with the 1080p60 H.264 clip) in the DXVA decode mode. Extra memory (GPU RAM) is also taken up in the DXVA decode mode as the decoder moves frames in and out during the decode process. In the software decode mode, the GPU memory load is lesser because frames are delivered by the software decoder, get to the GPU's memory and are taken in for post processing (calls made  by the EVR) and then delivered to the video output buffer. There is no need to move frames in and out for the decoding process itself. The amount of post processing done by EVR in both cases is the same, and that is the reason why there is no difference in the GPU's core load.

In the next section, we will see how the system fares under madVR, which is a much more demanding renderer compared to EVR.


Refresh Rate Handling HTPC Decoding & Rendering Benchmarks : madVR


View All Comments

  • jabber - Monday, May 07, 2012 - link

    I bought about a dozen of the first generation Atom boxes and they are all still trucking and the customers still love them.

    I still want one for myself.
  • TerdFerguson - Monday, May 07, 2012 - link

    For what they were meant for, the little ION machines were flipping fantastic. With a package price of below $200 for everything but the OS, it's a value proposition that hasn't been matched by anything since. Reply
  • duploxxx - Monday, May 07, 2012 - link

    yes there are but not all OEM have the guts to do it right and just stuff garbage onto consumers. If they love it means they have never used anything else...
  • BPB - Monday, May 07, 2012 - link

    Am I the only guy who goes to the bottom of the specs sheet first and looks fir price? This thing is way too much for an HTPC. Reply
  • duploxxx - Monday, May 07, 2012 - link

    what would you expect if you see following specs...

    Intel Sandy Bridge Core i5-2520M
    (2 x 3.00 GHz (3.20 GHz Turbo), 32nm, 3MB L2, 35W)

    Graphics NVIDIA GT 540M (1 GB VRAM)

    1 reason why you would need these 2 parts into a HTPC, can be replaced by 1 APU which cost less and consumes less in total, end of story.
  • BPB - Monday, May 07, 2012 - link

    I am not saying it isn't worth it. I am saying I see HTPC in the review title, look at the price, and think it's not worth reading the article. Simply can't see spending that on an HTPC, that's all. It is not a knock on the product. I'd be very happy owning this. Reply
  • cknobman - Monday, May 07, 2012 - link


    Over $1000 for a HTPC and then with these specs to boot?

    Im not saying the specs are bad but they are certainly not worth of over $1000.
  • mbzastava - Monday, May 07, 2012 - link

    I recall reading a nice comment from the Intel NUC article which points out how this new form factor is just repackaged laptop parts whith a nice new profit margin. I couldn't agree with him more.

    The question you should be asking is: Why does this unit cost around $1000 when you could get a similarly specced laptop for almost $300 less?
  • ganeshts - Monday, May 07, 2012 - link

    Economy of scale - How many such HTPCs are going to be purchased vs. how many laptops the vendor would sell. Reply
  • blackbrrd - Monday, May 07, 2012 - link

    I just use a laptop as a HTPC. You can get a decent laptop for waaay less than this costs, and you can use it as a laptop if you need one. Reply

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