Poor SD Performance with GeForce 6150 at High Resolution

[Mahoney]

Hi all,

I have a GeForce 6150 based motherboard which I am using for playback in Sage, with ForceWare 91.31 and PureVideo 1.223. I am playing back standard definition PAL MPEGS on a 1920x1080 screen. I have an Athlon 3000+ CPU and 512MB ram.

Performance is poor; if I set deinterlacing to "Automatic" in the PureVideo settings I get occasional dropped frames. If I set it to "Smart" I get a lot of dropped frames. Set to use hardware acceleration, naturally.

I would expect this system to handle SD playback without any trouble, so I'm confused! Certainly according to the product comparison table here:
http://www.nvidia.com/page/purevideo_support.html
it shouldn't be a problem for SD.

I am wondering if lack of RAM is the bottleneck, as I gather the 6150 uses system RAM. Or does upscaling to 1920x1080 put a huge strain on resources?

Grateful for any thoughts,
Rob

[paulbeers]

I'm going out on a limb here, but you are inessence taking a 480i image and requiring your client to deinterlace and upconvert everything upto HDTV quality. That would take quite a bit of power. If all you are doing is outputting SD, then I would recommend using 640x480 (or 800x600 or a widescreen format)and see how that flies. I bet that would work just fine. It seems to me, you are asking a lot from onboard video.

[IncredibleHat]

http://forums.freytechnologies.com/f...ad.php?t=19432

I am basically going through the same pains.

I have made a breakthrough in making my 6150 system run smoothly with SD playback in Sage... but now SageTV itself bombs out when I try to use any other program.

Its a long thread, but some of the better info is on the bottom.

[stanger89]

1080p could definitely be a stretch for a 6150, even if the source is only SD.

[IncredibleHat]

Originally Posted by stanger89

1080p could definitely be a stretch for a 6150, even if the source is only SD.

Actually, would it matter if the source is SD or HD... because either way, the end result is 1080p... right?

[blade]

Originally Posted by IncredibleHat

Actually, would it matter if the source is SD or HD... because either way, the end result is 1080p... right?

HD is much more demanding than SD.

[IncredibleHat]

Well... not to nitpick... but why?

The end result is 1080p irregardless. You can scale up a 170x96 movie file, and its still being output at the same higher resolution as a 1360x768 file. You don't change your screen res to match. So, pixel for pixel (thats all it is), the same amount is still being output at the same hz and speed. (?)

[stanger89]

Basically there's two things going on, decoding and rendering.

Rendering is probably roughly the same between both HD and SD sources, and mainly dependant on output resolution (assuming scaling is basically "free" on modern graphics cards).

The other part is decoding, and decoding HD is much harder than SD. HD has 6x the pixels, but beyond that, it's compressed farther, so there's more work to do to decode it. Purely on decoding, HD will take significantly more power (be it CPU or GPU or both) than SD.

Combine the two, and playing HD is harder than SD.

[IncredibleHat]

Thanks. Clears that up.

I guess I always thought the capture cards did all the decoding of signal to store it on the hard drive. Guess I was not right! LOL!

Thanks for the clarification. I will stop asking 'why' now =)

[GbrNole]

Originally Posted by IncredibleHat

Well... not to nitpick... but why?

The end result is 1080p irregardless. You can scale up a 170x96 movie file, and its still being output at the same higher resolution as a 1360x768 file. You don't change your screen res to match. So, pixel for pixel (thats all it is), the same amount is still being output at the same hz and speed. (?)

sorry but i just can't resist the irony here **irregardless** lol

that said 6150 boards have issues with the 91.33 drivers. try the older 88 series since they are much more efficient.

[stanger89]

Originally Posted by IncredibleHat

Thanks. Clears that up.

I guess I always thought the capture cards did all the decoding of signal to store it on the hard drive. Guess I was not right! LOL!

They do the encoding (compression) of the signal to store on the drive. Then on playback the CPU/GPU do the decoding (decompression) of the file.

[IncredibleHat]

Originally Posted by GbrNole

that said 6150 boards have issues with the 91.33 drivers. try the older 88 series since they are much more efficient.

Cant find "88" series... last I see are "84":
http://www.3dchipset.com/drivers/nvi.../nt5/index.php

I saw a beta 85 and 87 on the guru3d site... no crazy 88s

[Mahoney]

Thanks all. I was rather hoping for a "I'm using the 6150 at 1080p resolution for SD content no probs" response! I'm surprised, though - so many people are talking about getting good playback of 1080i content out of the 6150, I presumed SD would be a breeze, regardless of resolution.

[IncredibleHat]

Right, this is what I would figure too. I mean, everyone seems to say all the problem comes from 'decoding HD vs SD'... so, surely resolution output should not matter if its decoding a lower resolution (SD) signal. Output is output, like I saw someone say "resize is a free process".

One thing I have found though ... FSE makes a BIG FAT DIFFERENCE with my 6150 outputting SD to 1360x768p (meaning, it fse helps).

[stanger89]

Resize is probably about free (depends on how it's implimented), but the problem is rendering 1080p60 is a lot of pixels, and through the 3D pipeline. The 6150 is not a very powerful 3D chipset, it's not surprising it has trouble rendering 1920x1080@60.