Does vid card performance matter for video only?

[Ferris1]

Looking for an Nvidia 8-series video card for my HTPC. I do NO gaming but want to play any/all HD content. Aside from h.264 hardware acceleration, does GPU horsepower play any part in displaying 1080p and below content? I am outputting via DVI to a 60" 1080p plasma.

As long as I choose a card with hardware acceleration (8500, 8600, 8800GT), will a faster card make any difference at all or should I just go for the cheapest (or coolest/quietest). I have no problem paying for performance. I just don't need to waste money (and gain heat) if I don't get any benefit.

 

[CrimandEvil]

Yes but to an extent. Video cards don't have actually have hardware on them that is dedicated to decoding these certain video formats; they use the GPU and have it do all of the number crunching in order to 1.) decode video and 2.) do post processing to it to make it look nice.

So yeah, the faster the card the better quality you'll get but you don't need a whole lot of speed. At the absolute most you'd want a 8600GTS for HD content although you'll be fine with a 8600GT or even a 8500GT but anything lower then that isn't going to be all that great (you might as well go with an IGP).

 

[gfredsen1]

I see posts that the Radeon 2000 cards produce better picture quality and there was a recent review on Tom's Hardware which mentioned something about less (video) noise.
Also, when does it matter if you have 256Mbs of memory or 512, as regards Ferris' qualifications, which are exactly the same as mine.

 

[CrimandEvil]

I see posts that the Radeon 2000 cards produce better picture quality and there was a recent review on Tom's Hardware which mentioned something about less (video) noise.

I can't believe that theres someone that actually gives Tom's any credence for their "reviews."

Also, when does it matter if you have 256Mbs of memory or 512, as regards Ferris' qualifications, which are exactly the same as mine.

It doesn't.

 

[gfredsen1]

Thank you for your reply.

 

[m1abram]

I use a 2600Pro for my HTPC, however that is only because I upgraded it and did not want to buy a new motherboard. AMD 2XXX series are the fastest cards you can get right now on AGP platform.

If I had PCIe on my HTPC I would probably get an 8600GT.

 

[CrimandEvil]

I use a 2600Pro for my HTPC, however that is only because I upgraded it and did not want to buy a new motherboard. AMD 2XXX series are the fastest cards you can get right now on AGP platform.

If I had PCIe on my HTPC I would probably get an 8600GT.

Just to let you know, UVD isn't working on the AGP cards.

 

[m1abram]

Just to let you know, UVD isn't working on the AGP cards.

I know where you are getting your informatioin. Straight from ATI.

However I know that for at least 1080i MPEG2 streams the decoding is handled by the video card. I have not tested it with VC1 or H.264 yet.

 

[schizo]

If you think there's any chance of running linux on your HTPC, do not buy ATI under any circumstances. For windows it's fine.

 

[CrimandEvil]

I know where you are getting your informatioin. Straight from ATI.

However I know that for at least 1080i MPEG2 streams the decoding is handled by the video card. I have not tested it with VC1 or H.264 yet.

MPEG2 content is fine, it'll take a major screw up not to have it. The part that doesn't work is the VC1 and H264 decoding like you said. What sucks is that thats pretty much the only reason to buy one of those cards for an AGP based HTPC.

 

[m1abram]

Note I also just ran a 1080p test on my AGP 2600Pro. I grabbed some of the WMVHD files from MS. These are 1080p@24fps. They played flawlessly using only about 30% CPU usage on my Athlon X2 3800+.

since the WMVHD uses VC-1, I would say that my AGP card is in fact working as advertised.

 

[CrimandEvil]

since the WMVHD uses VC-1, I would say that my AGP card is in fact working as advertised.

VC-1 isn't that stressful, especially with an X2. What your seeing is simply the CPU doing the decoding (which looks to be the case since you're hitting 30% or so, unless thats only on one core. 30% usage on an X2 is spread across both cores so it's more like 60% on a single core).

Also, you're talking about HD files found on MS's site. Files designed to be downloaded; in other words the are encoded at a much lower bitrate then what would be found on a real HD DVD disc.

 

[m1abram]

I am pretty sure it is using Hardware Acceleration. Because if I turn off HA in the decoder the playback becomes a slideshow and CPU usage spikes to 100%.

Note in order to get wmvhd HA playback on the AGP versions you must install the ATI drivers from the card manufacturer the one from ATI will not work. Then you need to do a few reg hacks. But I am pretty damn sure it is working. I do not have access to any other test files, however if you have a few test files to try send them along.

Also the ones from MS have what appears to be a pretty decent bitrate. For a 1 minute 45 second clip the file was ~110MB. Sure it is not super high, probably though just slightly less than what would be found on an HDDVD.

 

[lawrence131]

I am pretty sure it is using Hardware Acceleration. Because if I turn off HA in the decoder the playback becomes a slideshow and CPU usage spikes to 100%.

Note in order to get wmvhd HA playback on the AGP versions you must install the ATI drivers from the card manufacturer the one from ATI will not work. Then you need to do a few reg hacks. But I am pretty damn sure it is working. I do not have access to any other test files, however if you have a few test files to try send them along.

Also the ones from MS have what appears to be a pretty decent bitrate. For a 1 minute 45 second clip the file was ~110MB. Sure it is not super high, probably though just slightly less than what would be found on an HDDVD.

Your CPU utilitzation actually seems pretty on par without GPU acceleration. I tested the same files on my Intel Quad @3.3ghz with a 7800GTX which does NOT have VC1 acceleration and I'm averaging ~10% CPU load on these files (spread over 4 cores). I'm assuming your using the files like Elephant's Dream and the other mini-movies or VC1 1080p samples downloaded directly from MS. I can run a stack of other apps and not even notice a stutter or impact on system performance at all, so I think what you're seeing is just the efficiency of current codecs with CPU decoding.

To confirm, I ran the same videos on a piece of crap ECS 945G IGP that came free with a E2160 CPU Fry's combo overclocked to 2.4Ghz and the average CPU load is close to 20%. If you're spiking to 100% on your X2 without GPU help there's something wrong with your system. Plenty of people have been playing HD content on crappy IGP's as long as they have a decent CPU.

Considering the scaling performance of our CPU's, 30% for yours seems about right without GPU acceleration for you. Intel C2D architecture is quite a bit better at video decoding clock for clock than ATI's X2 architecture.

A couple other interesting tests I tried out included H.264 decoding with and without a 7800GT on an Athlon 64 3200 Venice. Using two of the more popular codecs (CoreAVC professional and the FFDshow package), adding the 7800GT (which DOES support H.264 hardware acceleration) made absolutely no difference. With and without the 7800GT using the newest Geforce drivers, the Athlon simply could not handle H.264 decoding and stayed at 100% with lots of stuttering whether or not the 7800GT was added.

I also have a few X2 machines I can run those files on but I'm fairly positive they can be handled without GPU help as my examples above show. The 7800GT swapping also shows how software dependent GPU acceleration is - CoreAVC for sure does not support GPU acceleration as they announced their next version of CoreAVC professional should have it added. From my experience neither does FFDshow.