To CUDA, or not to CUDA? That is the question. (1 Viewer)

[digitalfm]

Hi,

I have the latest Nvidia drivers installed and version 1.9.5 of Core AVC.

I've noticed that in Media Player CUDA is activated fine. The Core AVC icon goes green, however in MediaPortal it does not activate. I'm using the same .mkv movie to test so it's not a codec issue. Any ideas why this woould work in MediaPlayer but not in MediaPortal. I have a Geforce 8600GTS. It's 256mb so wondering if there's not enough memory to use CUDA as well as running MP?

I suppose the next question however would be is any of this important. Does the picture quality improve with CUDA activated, or is CUDA solely handling video acceleration rather than any picture enhancements? If there's no picture enhancements at all then my CPU can continue to earn it's living the hard way.

 

[rtv]

Actually CUDA often leads to deterioration of video quality.
Several people already did 1:1 comparisons.

 

[tourettes]

Similar question would be "to DXVA2.0 or to DXVA-HD", of cource in MPII and with dropping the support for Vista & XP...

 

[magao]

The most likely cause of CUDA not working in MP is insufficient video memory. MP does use quite a bit of the video memory for itself, thus reducing the amount available for decoding. With only 256MB on the card, you might well be hitting the limit.

Try some 576p, 720p and 1080p videos and see if CUDA activates for any of them. Also see if you can borrow a 512MB card from someone to try out.

BTW, CoreAVC 1.9.0 had some pretty severe blocking problems with CUDA (which is what the linked thread talks about) - CoreAVC 1.9.5 has fixed those. To my naked eye (haven't done 1:1 comparisons) there is no difference in quality between MPC-HC, CoreAVC, ffdshow-tryouts or PowerDVD whether using software or hardware.

There are 2 big advantages to CUDA:

1. The CPU doesn't have to work as hard, this hopefully saving power (and allowing a lower-spec machine to handle higher-quality video);

2. The decoding is offloaded to the GPU, but the decoded video is available for post-processing on the CPU, allowing a lower-spec machine to do things like apply resizing, debanding, etc.

The 8600GTS was a fairly power-hungry card - if all you're using it for is an HTPC, I'd recommend replacing it with a 512MB 8400GS or 9400GT (and hopefully upgrade a family member's game playing capability on the cheap).

 

[bluesk1d]

It is definitely not a memory issue. I have an onboard Geforce 9300 that I use with CoreAVC (1.9.5)/CUDA and it works fine. A real card like your 8 series should be plenty. I also do not have any of the blocking that is apparent in the sample screenshots as noted by rtv in version 1.9.0. As far as I am concerned, it works great!

 

[nolem]

Hi,

I just got a new ION motherboard and it it got a 9300 on it or so (motherboard with a Atom 230 and fanless)

My problem is that CUDA doesn't work when I run in fullscreen mode in MP but works fine in windowed. If i try other players (mpc, wmp 11) they also playback fine in fullscreen (using CoreAVC + CUDA)

Im not sure whatever its a memory problem or but anyone got any idea?

Cheers!

Update:

Now it works for some reason. I switched to external player (mpc) just to test and that worked and now I switched back to internal player and now it works like it should. Really weird but im happy

 

[Win7]

Well there is one question for me. Can you use the cuda support of the nvidia graphic card even if you display the video on another card? Why i would like to do this? Lets think about a nice mainboard with intel onboard graphic that can handle the aero of vista or windows seven but has no support for dxva. Now i can use an nvidia graphic card and use it as primary card but even if its running at a lower clock in 2D mode it will consum much more power than the intel card. And MP is a 3D app so the card will work at higher clock even if its not needed. But if i can use the intel card as primary display i should be able to set a real low clock for the 2D mode of the nvidia card and i would expect the card to be clocked higher if cuda is used. Even it should be no problem to use a nvidia card with 256MB because mediaportal will eat the memory of the intel card.

My problem is i use an Scaleo E that powers up its coolers when the power supply needs to deliver more energy. I build in an ATI HD3450 Card and recognized MP displaying the home menu will cause often loud cooler noise. When i close MP the card lowers its clockrate and everything is fine. My problem ist that the cpu is to weak for hd material but with the ati card i have a much higher power consumption. For that i also have to pay.

Now how i think it should work. Mp is displayed on an intel gma X3100 as primary display that card can nearly nothing but it´s enough for displaying mediaportal. I would set a clock of 100 Mhz on the nvidia card in 2D mode should give me a very low power consumption when mp displays the home menu or plays some music. When i start a h264 video with the coreavc codec and cuda support, then the nvidia card should run at a higher clock and decode the video. Even nice would be that i could display hd content with subtitles at moment i can´t. Ok that could been done with the nvidia card a primary card, too.