IMovie only using 50% CPU power

Question

Hi,
When I export my project in iMovie my CPU usage holds at 50%. I accept this does mean I can do other things but would like the export to go faster.
Is this usual for iMovie to only use 50% CPU (and only about 1gb of RAM (of 8gb)) or do I need to do something?
New to Macs so any help appreciated.
dcbevan

Answer 1

Hi
As I get it - Doesn't iMovie take full use of multiple core processors. Not even Pro
applications does this to 100%
BUT
RAM - iMovie or FinalCut are not that RAM hungry - 1 to 2 GB would be OK
Free Space on Start-up hard disk - VERY IMPORTANT
• 25Gb my minimum for iDVD
• 10Gb my minimum for iMovie
• 5Gb and iMovie runs slow and instable
• <1Gb and iMovie might not run OK at all
Other applications running in paralell - results in bad performances
• Energy Saver
• Do not spinn down hard disks
• Use of USB/USB2 external hard disks = Slow and bad performances especially when getting full
FireWire or internal e-Sata performs best.
• Screen savers - may be (by directing it to an empty folder - I got the feeling of slight increase
in performances)
My list on howto speed up iDVD Slightly - might also applie on iMovie.
*Speed up iDVD*
To speed up iDVD
TO GET IT TO WORK SLIGHTLY FASTER
• Minimum of 25Gb free space on Start-Up hard disk - if less than 5Gb slow and unstable - less than 1Gb might even not start.
• Choise of encoding method will give very different productions speeds. On my d-G5 2GHz
*Professional Quality (movies + menus up to 120 min.)* - BEST
Takes about 2 x times the other ones - but if quality is of essence
(Quality might be as good as or even better for movies under 60 minutes - by using Best Performances BUT not for movies up to 120 minutes)
2 hour movie + menu = about 4 hours to encode at it’s best on my system
*Best Performances (movies + menus less than 60 min.)* - High quality on final DVD
1 hour including menu = about 1 hour to encode
*High Quality* (in iDVD08 or 09) / Best Quality (in iDVD6) *(movies + menus up to 120 min.)* - slightly lower quality than above
2 hours including menu = about 2 hour to encode
• Use an as simple DVD-menu possibly without any animation at all. This reduces processing speed dramatically. I use ”Old Theme - and Brushed Metal” and animation turned off.
• An as fast Mac and as many cores/CPUs possibly. My PowerMac G5 has two CPUs and iDVD uses about 120% = use more than only one CPU/Core. How many it can address I don’t know (anyone ? )
• If possibly - Use two internally e-Sata drives - Drive access takes a great deal of time
else FW-800 or FW-400 or USB2 or network storage (slowest and near to useless)
to work on one (internal, boot, Mac OS, Start-up hard disk - will be BAD - and slow
Normally my d-G5 2GHz takes about 2 x movie material when iDVD and Mac OS on one internal HD and material is on the other internal one.
Now with material on an external USB2-drive and an external Lacie FW-400 as Start-up drive material of about 1.5h will need about 4-6 hours to get encoded and burned to DVD.
Choise and use of hard disks is essential.
• I guess that a Solid State Disks might improve speed
• No other programs running in BackGround eg EnergySaver, Internet, AirPort, Bluetooth etc.
• Don’t let HD spinn down or be turned off (in EnergySave)
• Move hard disks that are not to be used to Trash - To be disconnected/turned off
• Goto Spotlight and set the rest of them under Integrity (not to be scanned)
• Set screensaver to a folder without any photo - then make an active corner (up right for me) and set
pointer to this - turns on screen saver - to show that it has nothing to show
• If Mac with only place for one internal hard disk. Then I would try to use an external FW (Mac OS Extended) one as Start-Up hard disk and store material on the internal one.
eg iMac or ProBook or alike.
from Karsten -
• I assume that resolution and codec of source is another factor ... scaling (e.g. 1280x720 to 720x576 = that is an 'un-even' calculation). or, a difference in speed reg. to h264, dv-stream or aic as input ....
Yours Bengt W