Videomaker – Learn video production and editing, camera reviews › Forums › Technique › Production Gear › iMac & super slow rendering!!! Why?
December 6, 2009 at 4:30 AM #44149bnixonParticipant
I have a white 24″ iMac (first gen Intel chips) and am running Final Cut Express to do some painting lesson videos. These are pretty basic stuff with minimal effects. They are rendering super slow. A 20 minute video took 24 hours to export using the standard Vimeo HD quicktime settings.
My machine has the max amount of ram 4 gigs with a internal 250 GB drive. I have several external Lacie drives hanging off of it for storage and backup. One 1TB on the FW800 port One 1TB on the FW400 Port and a 500GB off of the usb port. I have my source video files on the FW800 drive and the FCE project on the FW400 drive with all apps and os on the internal drive. All of the video is shot in full 1920X1080 HD from a Canon HF100 AVCHD
I don’t know where the bottle neck is…Bandwidth to the hard drives, lack of memory, or just processor speed. I would like to get this machine to perform reasonable so I don’t have to purchase a new one.
I am sure there is a way to improve the horrible speed but I am ignorant of how to setup this machine for higher performance. Any help would be greatly appreciated.
thanks for your time,
December 6, 2009 at 4:56 AM #185036RobParticipant
“My machine has the max amount of ram 4 gigs with a internal 250 GB drive. I have several external Lacie drives hanging off of it for storage and backup. One 1TB on the FW800 port One 1TB on the FW400 Port and a 500GB off of the usb port. I have my source video files on the FW800 drive and the FCE project on the FW400 drive with all apps and os on the internal drive.”
I like the way you are organizing your media and project files, but unfortunately all of that has very little to do with rendering time. Processor speed is where it’s at, however, a video of that length should not take that long to compress for Vimeo.
I think the issue is that you shot AVCHD video. AVCHD is compressed in a way where video frames share data with one another. If you want to compress video in this format to another, more compressed format, your processor is having to look at many frames at a time to determine how best to compress the video. Does that make sense?
If all you are doing is exporting for web, then I suggest editing in DV/NTSC. Yes, it’s standard def, but you’re only delivering to the internet, and because DV is an I-frame codec, the processor is compressing one frame at a time, rather than looking at multiple frames at a time.
December 6, 2009 at 6:01 AM #1850378stringParticipant
As Rob says, it could be the format, (could it be the Express product?) but I would just double check that you have disk space on the main drive in the machine. Since you say it’s the ‘original Intel’ you may have had this around a while and if the disk has less than 20% capacity left, you may be running out of disk space. This could lead to more churn between memory and disk, and might be affecting overall performance. Have you watched Activity Monitor while this process was running? Also, how is your paging when this is happening? Other than that, you might want to run some comparison tests with the same clip being compressed into various formats.
I’ve seen a lot of complaints about the Express version of the product, but not sure what could be wrong with it. Is this version of FPE a true 64 bit app yet? And what OS version are you running? It’s possible, that if the app is true 64 now, and you upgrade to Snow Leopard, you might increase your speed of processing, but this brings along a bunch of baggage with other apps you may have, like ProTools compatability, etc …
Going back to basics in that you run comparision benchmarks of this rendering on various platforms, (see if a friend with FCP Studio can run it for you too), will allow you to see if it’s the format, the machine, the application, or
Anyone know if this is a job for a Matrox w/Max? I’m unclear if starting from AVCHD would require a Matrox…do I just not understand this device? I’ve been looking at them and if it does what it says, it seems a lot cheaper than a new MPro! http://www.matrox.com/video/en/products/mac/max/realtime/#max_graph
December 6, 2009 at 3:24 PM #185038D0nParticipant
I’m thinking there’s something wrong with your mac.
zap your pram, repair disk permissions using your startup disc.
then run a test on your ram.
when done that (search apple forms if unsure how) you may want to check out “Onyx” free from Vesrion Tracker.
now you got a clean bill of health on your mac, time to tune up FCE.
check your settings to make sure you aren’t using your internal drive as a scratchdisc for your media…
you may try tweeking your set up to have the audio scratch disk on the 800 firewire disk and your video scratchdisc on the other external drive for example.
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