NVIDIA and ATI HDCP Compatible Graphics Cards Roundup
by Josh Venning on November 16, 2006 12:00 AM EST- Posted in
- GPUs
CPU Utilization
Of course gaming performance is only part of the equation when it comes to looking at these HDCP compliant cards, the other major aspect is CPU utilization during high definition movie playback. Today we're only able to provide a small subset of HD movie playback performance as we're only testing with a MPEG-2 encoded Blu-ray title. We're still waiting for a PC HD-DVD player which will let us test VC1 and H.264 decode performance as well, but for now we're only able to look at high bitrate MPEG-2 content. VC1 and H.264 encoded content will put more stress on the CPU and GPU as a whole, but we'll unfortunately have to wait a little longer before testing it.
Just like when graphics cards started becoming important for offloading graphics processing with games like GLQuake, we are in a kind of transition period where it is becoming necessary to also have cards that can process our video playback for us. For the past couple of years ATI and NVIDIA products have been handling video decode acceleration, but it hasn't started to be really necessary until HD-DVD and Blu-Ray came around. The complex video formats they provide require more processing power to decode, meaning that slower processors won't be able to play them back without help from a graphics card.
Right now, since Blu-Ray titles are predominantly MPEG-2, having lots of extra power in a graphics card to accelerate the decode process isn't extremely important, but we still want to take a look at how much load the cards can take away from the CPU. With this in mind we put together a benchmark, recording the average CPU utilization of a period of about one minute of Blu-Ray movie playback. The movie we used was Click, and we tested each of the cards with the exact same one-minute segment of the movie. Audio was also enabled for this test.
Here are the CPU utilization results from each of our cards.
Video decode acceleration on NVIDIA GPUs is handled by the PureVideo processor, which is tied directly to the core clock speed, so the CPU utilization of each card will reflect this. The end result is that an NVIDIA card with more pipelines that is better at 3D performance will not necessarily be better at video decoding. With ATI, its AVIVO decoding is also tied to the processing power of the card, but is not quite as related to the clock speed as it is with NVIDIA. We also found that there was a bit of variance between multiple runs of the same tests, but these tests give us a general view of the CPU utilization of each of these cards.
We can see that the X1900 XT 256 gets a very low average CPU utilization compared to the other cards. Also, the 8800 GTX and 8800 GTS offloaded more processing from the CPU than the other NVIDIA cards, which isn't very surprising given that NVIDIA mentioned that the PureVideo core is a bit faster in G80. For reference, we measured the CPU utilization of the Blu-Ray playback benchmark with hardware acceleration disabled, and we got an average of 51.0%, giving us an idea of how much work these graphics cards take off the CPU. The Gigabyte 7600 GS doesn't seem to help in this area at all, and it makes sense when we consider that it's the slowest clocked NVIDIA card of the group. It would appear that a 400MHz clock speed doesn't provide enough power with PureVideo to make a difference in CPU utilization.
Even taking into account these results, CPU utilization isn't going to make a big difference between which of these cards would be better choices than others. Until we can look at H.264 and VC1 decode performance we will have to focus on other important factors to consider such as power, heat and noise.
Of course gaming performance is only part of the equation when it comes to looking at these HDCP compliant cards, the other major aspect is CPU utilization during high definition movie playback. Today we're only able to provide a small subset of HD movie playback performance as we're only testing with a MPEG-2 encoded Blu-ray title. We're still waiting for a PC HD-DVD player which will let us test VC1 and H.264 decode performance as well, but for now we're only able to look at high bitrate MPEG-2 content. VC1 and H.264 encoded content will put more stress on the CPU and GPU as a whole, but we'll unfortunately have to wait a little longer before testing it.
Just like when graphics cards started becoming important for offloading graphics processing with games like GLQuake, we are in a kind of transition period where it is becoming necessary to also have cards that can process our video playback for us. For the past couple of years ATI and NVIDIA products have been handling video decode acceleration, but it hasn't started to be really necessary until HD-DVD and Blu-Ray came around. The complex video formats they provide require more processing power to decode, meaning that slower processors won't be able to play them back without help from a graphics card.
Right now, since Blu-Ray titles are predominantly MPEG-2, having lots of extra power in a graphics card to accelerate the decode process isn't extremely important, but we still want to take a look at how much load the cards can take away from the CPU. With this in mind we put together a benchmark, recording the average CPU utilization of a period of about one minute of Blu-Ray movie playback. The movie we used was Click, and we tested each of the cards with the exact same one-minute segment of the movie. Audio was also enabled for this test.
Here are the CPU utilization results from each of our cards.
|
CPU Utilization |
Avg | Min | Max |
| NVIDIA Gigabyte GeForce 7600 GS | 51.5 | 41.4 | 58.2 |
| NVIDIA ASUS GeForce EN7600 GT | 45.5 | 38.8 | 50.8 |
| NVIDIA MSI GeForce NX7600 GT Diamond Plus | 46.9 | 38.3 | 52.9 |
| NVIDIA MSI GeForce NX7600 GT | 45.8 | 39.1 | 51.6 |
| NVIDIA Albatron GeForce 7900 GS | 45.8 | 36.7 | 54.7 |
| NVIDIA EVGA e-GeForce 7900 GS KO | 44.5 | 37.5 | 52.3 |
| NVIDIA Leadtek WinFast PX7900GS TDH Extreme | 44.8 | 36.7 | 51.6 |
| NVIDIA MSI GeForce 7900 GS | 45.9 | 38.3 | 52.3 |
| NVIDIA MSI GeForce NX7900 GT | 44.9 | 38.3 | 51.6 |
| NVIDIA EVGA e-GeForce 7950 GT KO | 43.9 | 35.9 | 50.0 |
| NVIDIA Gigabyte GeForce NX7950 GT | 44.4 | 36.7 | 51.6 |
| NVIDIA PNY GeForce 7950 GT | 44.3 | 36.7 | 52.3 |
| NVIDIA XFX GeForce 7950 GT HDCP | 44.1 | 35.2 | 53.1 |
| NVIDIA Sparkle Calibre 7950 GT | 44.1 | 35.9 | 64.1 |
| NVIDIA BFG GeForce 7950 GX2 | 46.3 | 36.7 | 53.1 |
| NVIDIA EVGA e-GeForce 7950 GX2 | 46.2 | 39.8 | 53.1 |
| NVIDIA GeForce 8800 GTX | 38.7 | 29.7 | 46.9 |
| NVIDIA GeForce 8800 GTS | 39.8 | 31.2 | 48.8 |
| ATI Powercolor Radeon X1600 PRO HDMI | 40.6 | 28.1 | 50.0 |
| ATI Sapphire Radeon X1950 XTX | 36.3 | 28.9 | 44.5 |
| ATI Radeon X1900XT 256 (reference) | 34.2 | 28.1 | 39.8 |
| ATI Radeon X1650XT (reference) | 38.3 | 28.1 | 46.1 |
Video decode acceleration on NVIDIA GPUs is handled by the PureVideo processor, which is tied directly to the core clock speed, so the CPU utilization of each card will reflect this. The end result is that an NVIDIA card with more pipelines that is better at 3D performance will not necessarily be better at video decoding. With ATI, its AVIVO decoding is also tied to the processing power of the card, but is not quite as related to the clock speed as it is with NVIDIA. We also found that there was a bit of variance between multiple runs of the same tests, but these tests give us a general view of the CPU utilization of each of these cards.
We can see that the X1900 XT 256 gets a very low average CPU utilization compared to the other cards. Also, the 8800 GTX and 8800 GTS offloaded more processing from the CPU than the other NVIDIA cards, which isn't very surprising given that NVIDIA mentioned that the PureVideo core is a bit faster in G80. For reference, we measured the CPU utilization of the Blu-Ray playback benchmark with hardware acceleration disabled, and we got an average of 51.0%, giving us an idea of how much work these graphics cards take off the CPU. The Gigabyte 7600 GS doesn't seem to help in this area at all, and it makes sense when we consider that it's the slowest clocked NVIDIA card of the group. It would appear that a 400MHz clock speed doesn't provide enough power with PureVideo to make a difference in CPU utilization.
Even taking into account these results, CPU utilization isn't going to make a big difference between which of these cards would be better choices than others. Until we can look at H.264 and VC1 decode performance we will have to focus on other important factors to consider such as power, heat and noise.
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LoneWolf15 - Tuesday, November 21, 2006 - link
Behind Enemy Lines? Explains why Blu-Ray adoption is so slow.NullSubroutine - Friday, November 17, 2006 - link
I think ATi er AMD had been working on the drivers for GPU accelration for HD movies longer than Nvidia is all. You only have so much resources in a given department, it would make seense that Nvidia put more focus in other things (like Linux drives) where as Ati was working on this and Folding @ home stuff.dickie1900 - Friday, November 17, 2006 - link
Do you think the results will change for the 8800s when DX10 rolls out with Vista or are we going to have to wait for games to be developed that use some of the newer instructions?DigitalFreak - Friday, November 17, 2006 - link
I would doubt it. I don't believe Blu-Ray/HD-DVD decoding has anything to do with DirectX.DigitalFreak - Friday, November 17, 2006 - link
Dude, it's a unicorn. :-)
phusg - Friday, November 17, 2006 - link
First off, thanks for the great review.Why not? Many people just look at the graphs and this way they would miss out on the 2 quietest cards.
Also (unrelated), it's a shame there was no mention of AGP cards. I'm sure I'm not the only one looking to stretch the life of their AGP HTPC.
And one more thing (unrelated), aren't there initiatives that are looking to handle the HD decoding in software? I'd love a review of these. What is the slowest CPU you can decode HD content with?
mino - Wednesday, November 22, 2006 - link
I second that.EVERY noise measurement should include reference of the bacground (system without the thingie which noise one measures).
As those 0dB would would not be 0dB. There would be the noise of the system without the noise of the card - hence the bacground noise.
Try to consider that in the future. No much work required for MUCH information added.
Spoelie - Friday, November 17, 2006 - link
coreavc is the fastest h264 software decoder, no competitionTheir cpu-only implementation is most of the time faster than the competition WITH gpu support, but they're working on gpu support as well.
It is payware tho.
http://coreavc.corecodec.org/">http://coreavc.corecodec.org/
NullSubroutine - Friday, November 17, 2006 - link
I originally had written this up in response to an artical that MS Office has mandatory authentication checks when doing updates. However, I think the idea of what the "intellectual property" industry is putting consumers through is rediculous.....this just in, cars now 'phone home' to validate the vehicial is authentic prior to fixing factory installed parts.....refridgerator units must now be activated via phone call before the cooling units will work....lotion now comes with EULA, which is automatically agreed to at time of purchase (information is inside the bottle)....desk drawers will now automatically lock after free trial period has ended....fees must now be paid to bacteria colonies each time a user flushes the toilet....due to people stealing food, the price has increased 1000x, if the food is not authentic it will tell you, via voice, that your food is not real food, and where authentic food can be purchased if you give the food companies the information on where your not real food was purchased; when asked about the policy, supporters claimed that food was an optional luxery, paint companies now produce super ultra high quality paint products - but can only be applied with a special paint brush on special surface (microchips installed) or else the paint looks like normal paint - when cosumers were asked about the new paint they said it looked great but unless they wanted to buy all new everything, it was all meaningless...
shecknoscopy - Thursday, November 16, 2006 - link
Wow... the Blu-ray era's off to a stunning start, eh? No more complaining about the poor game options for the Wii launch, when the stunning new world of BLU-RAY is kicking off with "Click."
Lawdy, help us.
-Sheq