choppy HD playback in quicktime

[uchiha_itachi]

Hiya, just trying to find out what part of my system is the cause for choppy HD playback when I view HD trailers in quicktime.

The problem is only limited to 1080p resolution, and not with 720p or 480p. It seems I fit all the system requirements according to apples website:

http://www.apple.com/quicktime/guide...endations.html

My system:

Athon64 3200+ 2.2ghz (Socket 754)
1gb DDR pc3500 ram
Geforce 4 ti-4800 128mb
Win xp pro

So which one would I have to upgrade to get smoother playback?

[davidstone28]

Lol, its that nasty Nvidia card.

Had absolutely hideous problems at 1080p even with a 6800 and its laugable "PureVideo" technology.

[Sumanji]

IS HD video playback really that demanding on the GPU?!

Suman

[5lab]

yes. uncompressed video, at that res (1080p) needs something silly for bandwidth - 1080x1920x32x60 bits per second (i think) or nearly 4 gbits/sec.. thats a LOT of data for a gpu to handle.

[arthurleung]

You need a faster CPU
What monitor are you running it on? I find that if you're not watching it 1:1, the computer need to do extra job to scale down the output image (which takes up quite a lot of CPU)

BTW 1080p and 720p will look the same if your monitor is <19" / LCDTV

[uchiha_itachi]

I'm running it on a 23" Cinema HD Apple Display, and have it running at 1:1, didn't think my cpu would be the cause of it. I did suspect the graphics card tho.

[Skinleech]

It's the quicktime files, not your pc. I have some 1080i and 1080p footage in the original .ts format, and playback is smooth as. 1080 quicktime files though, have a slight stutter to them.

My system specs are comprable to yours (see profile bar). In saying that, ditching the Ti4800 wouldn't go amiss.