NVIDIA GeForce 8600: Full H.264 Decode Acceleration
by Anand Lal Shimpi on April 27, 2007 4:34 PM EST- Posted in
- GPUs
Yozakura (H.264)
The Yozakura test isn't the highest bitrate test we have, but it is the most stressful we've encountered due to how it uses the H.264 codec. Our benchmark starts at the beginning of chapter 1 and continues until the 1:45 mark.
We start off with PowerDVD and immediately we see the tremendous difference that NVIDIA's new video decode engine offers. While even the previous generation NVIDIA hardware still eats up more than a single CPU core, the 8600s average in the low 20% for CPU utilization.
All of the steps that happen outside of the green box are responsible for any remaining CPU utilization seen when playing back H.264 content on a GeForce 8600.
Why isn't the CPU utilization down to 0%? The entire H.264 decode pipeline is handled on the GPU, but NVIDIA claims that the extra 20% is simply related to processing and decrypting data off of the disk before it's passed on to the GPU. If you had an unencrypted disk, the CPU utilization should be in the single digits.
The maximum CPU utilization for these two cards is still significant, but obviously much better than the 70%+ of the competitors. Surprisingly enough, ATI's hardware actually does worse than NVIDIA's in these tests despite offloading more of the decode pipeline than the GeForce 7 or 8800.
To confirm our findings we also ran the tests under WinDVD 8, which as we mentioned before doesn't support ATI hardware acceleration so the only GPUs compared here are from NVIDIA.
NVIDIA's older hardware actually does worse under WinDVD 8 than under PowerDVD, but the 8600 does a lot better.
Maximum CPU utilization is particularly better on the 8600s under WinDVD 8, the two never even break 24%.
Looking at the PowerDVD and WinDVD scores, it's interesting to note that while the 8600 GTS is clearly faster in PowerDVD, the two cards are basically tied under WinDVD. There is definitely room for further optimizations in PowerDVD at present, so hopefully we will get that along with bug fixes in a future update.
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Anand Lal Shimpi - Friday, April 27, 2007 - link
I corrected the statement, we will have our 8500 review sample in the coming weeks :)Take care,
Anand
kilkennycat - Friday, April 27, 2007 - link
Anand, you need to keep an eye on both ZZF and Newegg on release dates for new computer hardware, just in case your review versions don't materialize. The MSI 8500GT (o/c version, irc) was orderable and In Stock at ZZF @10PM Pacific Time on April 16 and continued to be in stock for at least part of April 17.JarredWalton - Saturday, April 28, 2007 - link
We know they're available, but if we ran out and purchased every piece of new hardware for testing rather than relying on our partners, that can start to put a pretty sizable dent in the old paycheck. Not that we don't often purchase hardware anyway....mmp121 - Friday, April 27, 2007 - link
Page 3 paragraph 1, last sentence ends abruptly.Could you comment on what you are confirming?
Anand Lal Shimpi - Friday, April 27, 2007 - link
Just confirming that the two 8600s perform the same despite their differences. Thanks for the correction :)Take care,
Anand
WarlordBB - Friday, April 27, 2007 - link
Did I miss it, or did you mention it in a previous article?What the heck are you using for your HD-DVD drive?
mmp121 - Friday, April 27, 2007 - link
Most likely the XBOX360 HD-DVD drive. Or heck, maybe he ripped it to HDD?Anand Lal Shimpi - Friday, April 27, 2007 - link
We used the Xbox 360 HD-DVD drive. We would never rip a HD-DVD movie to HDD, that would be illegal of course ;)DerekWilson - Friday, April 27, 2007 - link
quite ... of course, inspite of the fact that ripping the HD or BD movie is illegal (DMCA violation), *having* the HD or BD movie on your HDD is protected by fair use ...as Anand alluded to, though, playing back content that isn't aacs protected would result in lower cpu utilization and wouldn't be reflective of the average consumer experience.
Ard - Friday, April 27, 2007 - link
Well, strictly speaking that's not exactly true. Having a ripped movie on your HDD, assuming you legally own the movie in question, is certainly a fair use due to the software archival provisions in the Copyright Act. However, since the DMCA is itself a part of the Act, having the movie on your HDD essentially becomes de facto illegal because the only way you could put it there is through ripping, which, as you stated, is illegal anti-circumvention. It's things like this (the chilling of fair use and extension of copyright owners' rights) that make me hate the DMCA and all who would use it for their gain.On topic, I'm glad to see that the 8600 line is capable of significantly decreasing CPU utilization. I wasn't expecting a drop from 80+% to 24%. It's really incredible.