Sidebar Sidebar
Become a MacRumors Supporter for $50/year with no ads, ability to filter front page stories, and private forums.

Puzzled: QuickTime performance on 2008 MP octal vs 2013 MBP

D

dampsquid

macrumors newbie
Original poster
Jul 23, 2011
16
8
Just got a Gopro (love it) took video (1080 48fps) straight off card and copied to SSD drive on MP. Was surprised playback with QT stutters now and again. Scrubbing in QT is very jumpy. Copied same file to MBP and it's silky smooth, both in x1, faster, and scrubbing back and forth. Can't fault it.

Looked on Activity Monitor, found some significant differences:

MP: QT CPU ~18%, VTDecoderXPCService CPU ~130%, Disk read 3-4Mbit/s
MBP: QT CPU 15-18%, VTDecoderXPCService CPU 0%, Disk Read: 3-4Mbit/s

when the mbp stutters that coincides with both QT and VTDecoder' utilizations dropping significantly too.

Any one any idea why I'm seeing this difference in behaviour?

Configs:
MP: 2008 8 core, 2.8 GHz, 20GB, SSD boot, SSD scratch (where file is), spinning 'data' drive, HD5870
MBP: 10,1 2.3GHz i7, 16GB, factory SSD.
 
acearchie

acearchie

macrumors 68040
Jan 15, 2006
3,264
104
dampsquid said:
Any one any idea why I'm seeing this difference in behaviour?

Configs:
MP: 2008 8 core, 2.8 GHz, 20GB, SSD boot, SSD scratch (where file is), spinning 'data' drive, HD5870
MBP: 10,1 2.3GHz i7, 16GB, factory SSD.
Click to expand...

Have you tried playing it back in VLC?

I have had some issues a few times with older CPUs not playing back the video quite as well.

Are they the same OS and both up to date with software updates?
 
D

dampsquid

macrumors newbie
Original poster
Jul 23, 2011
16
8
Both machines are up to date on 10.8.4

VLC works fine on both machines, doesn't stutter on the mp like QT does. That said, it doesn't seem to skim as well as QT does.

What I'm hoping for is some insight into why the VTDecode... process is running at >>100% on the mp and 0% on the mbp...?
 
D

dampsquid

macrumors newbie
Original poster
Jul 23, 2011
16
8
Thanks for your reply. Can I ask, is that speculation on your part, or do you know it to be so? I wondered about that too -
Perhaps a remore pertinent question is can the mp be persuaded to use the HD5780?
 
P

Policar

macrumors 6502a
Nov 21, 2004
662
7
I find gopro footage to play back very slowly, too, although the footage I used was 24fps 2.7k. It might be the codec.
 
C

ChrisA

macrumors G5
Jan 5, 2006
12,572
1,684
Redondo Beach, California
dampsquid said:
What I'm hoping for is some insight into why the VTDecode... process is running at >>100% on the mp and 0% on the mbp...?
Click to expand...


QT is using OpenCL. In other words QT is using the GPU if it is available and the CPU otherwise. Your new MBP has a GPU that OpenCL can use.

You could upgrade the graphic card on the MP to one that is supported by current versions of OpenCL. But the cost is very high. The card costs 1/4 as much as a new MP. You'd be better off selling the old MP and buying the new MP than dumping $1000 to $500 into an upgrade.
 
Mr. Retrofire

Mr. Retrofire

macrumors 603
Mar 2, 2010
5,064
518
www.emiliana.cl/en
ChrisA said:
QT is using OpenCL. In other words QT is using the GPU if it is available and the CPU otherwise. Your new MBP has a GPU that OpenCL can use.
Click to expand...
QuickTime X does not use OpenCL or Quick Sync to decode the video data streams. QuickTime uses specialized units of the discrete or integrated GPU which decode the video data. That is the reason why QuickTime X supports the hardware accelerated decoding of H.264 data even on older (2009) integrated GPUs, like the NVIDIA 9400M. As you know, the 9400M does not support OpenCL and does not support Quick Sync.

AFAIK, Apple uses the Quick Sync decoder/encoder unit only for AirPlay video data streams. Nothing else.
 
You must log in or register to reply here.
Register on MacRumors! This sidebar will go away, and you'll see fewer ads.
Top Bottom