NVIDIA's PureVideo HD: HD-DVD Playback on the PC

Final Words

So the burning question on everyone's mind is: what does all this mean for the user who wants to play HD content on their PC? A graphics card that can accelerate the playback of 1080p HDCP content will be something hardcore enthusiasts will want. While what we saw in our tests shows that the GPU can only really "relieve" 20% of the total CPU load on a Pentium D 830 (2 NetBurst cores running at 3.0GHz each), this early content isn't encoded at anywhere near the highest bit-rates supported on HD media, and NVIDIA expects to move more of the pipeline onto the GPU with future driver updates.

If the system will be used to play back imported Japanese films, the need for GPU decode acceleration is increased. As our tests show, the system pegged the CPU without GPU assistance and frames were dropping left and right. The fact that Japan is using H.264 for all their content does give decoders a harder time. Granted, we didn't use the fastest CPU around, but the number of dropped frames did render the movie unviewable.

Let us reiterate that while the videos we recorded do demonstrate the difference in the viewing experience with and with a GPU on the D 830, compressing video caught at 30 fps with a DV cam of content being played back at 60fps on a TV is inevitably going to smooth over some of the motion flaws in the original. The differences are much more dramatic in person.

Of course, there is some question of how other CPUs will handle the content, and we haven't had a chance to thoroughly investigate the matter yet. A Pentium D 830 is no slouch of a CPU, but neither is it extremely fast. Depending on the decoding algorithm (i.e. CPU optimizations) being used, many dual core processors out there may outperform the Pentium D 830 - but we will have to investigate this further when we have hardware. It almost goes without saying that we fully expect even the lowliest of Core 2 Duo processors to be able to handle 1080p content (with any encoding), though they will still likely be very close to 100% CPU usage. For those of you still running single core CPUs, things aren't looking too good right now as far as high definition support. It appears that NVIDIA, ATI, or someone else is going to need to do far more than offloading 20% of the CPU requirements before any single core CPU is going to be able to manage 1080p decoding without dropping frames.

Anything less heavy duty than H.264 (read: all current American content) is watchable without GPU accelerated decoding enabled on the system we tested. VC-1 seemed to run near the limits of the system, but didn't run into the same trouble we saw while watching the Japanese version of The Chronicles of Riddick. For the general American HD content consumer with a PC, a decent (dual core) midrange system will be able to playback video just fine.

Right now doing anything while watching HD content isn't a good idea. If NVIDIA moves more decode onto GPU, we could free up resources for background tasks. Lack of power savings and low bit-rate content diminish the need for GPU decode on most current CPUs right now unless Japanese importing is important (larger regions make this easier).

It may still be possible to build a quieter system using PureVideo HD because, while power isn't saved over the whole system, all the power isn't dissipated in the same spot. This could lead to relaxed cooling requirements. In fact, there are a good number of silent 7300GS cards that run at over 500 MHz. While they don't have enough pixel power to run the latest games at any decent quality or resolution, the clock speed makes it an excellent option for PureVideo HD (provided one of the vendors making HDCP cards opts to build a 7300GS). As for cards that are coming out soon, MSI and ASUS both have 7600 based products with HDCP planned for the near future. MSI even has an HDMI product coming down the pipe Real Soon Now.

PureVideo HD is a very good thing. We would love to see NVIDIA pull more of the decode pipeline onto the GPU, and CyberLink could still benefit from some time improving PowerDVD. Naturally, as this is all still beta, we can cut them a little bit of slack. However, once players are available in good quantities for decent prices with competition from ATI's AVIVO thrown in for good measure, we expect to see improvement.

We are very interested in seeing how ATI's AVIVO compares to PureVideo HD. As soon as we are able, we will have a comparison of the two, and we will also test with additional CPUs. Until then, HDCP support is a good thing, PureVideo HD nice, and the near term HDMI cards will also be useful for the home theater crowd. However, for most of us, at this point these things are merely interesting features. It's a little bit early to make a recommendation on buying HDCP enabled hardware for the multimedia enthusiast, especially given the current cost of optical drives. If this is something you need, the best bet will be to wait until everything is available in retail and we've seen the cards ATI is holding.