slow render RAM issues.
by djeddy
on
Nov 8, 2006 at 3:48:16 pm
hey guys..
i got two computers both identical in speed running AE7.
when i render out a background..one computer is able to render out the background in about 2 minutes with a top amount of 60% used out of 3.0 GB. while the other takes more than 10 minutes, with the ram used percentage consistent at 3% out of 3 GB.
the faster computer is a G5 2.3 dual at 4.5GB RAM...and the slower is a G5 2ghz dual with 4.5GB RAM.
now i know that the processor could be culprit for the slowdown, but this computer used to render much quicker at 60% used out of 3GB...what could be causing it to stick to 3-5%????? is there something in the settings that could be causing this??
Re: slow render RAM issues. by Steve Forde on Nov 8, 2006 at 4:31:33 pm
I think there are 2 things at play here....
1. Fragemented RAM. Did you restart both machines before running the test? OS X has a nasty habit of not giving up "Inactive RAM". You can see this in the pie chart (its the stuff in blue) provided by Activitiy Monitor in your Utilities folder.
What happens is, OS X will not provide the RAM to AE, even though AE will report the RAM as being free. Hence your 3% usage. Shutdown and restart usually fixes this problem.
2. Is everything equal on both machines? OS Version, Updates etc? I do know there was a memory bus update between the 2GHZ and 2.3GHZ, but I don't believe that would be enough to cause this result.
As you can see, there are a multitude of factors that can cause slowdown or speedup. RAM, CPU and Disk, as well as restarts, updates and background process can all have an effect on render performance.
Re: slow render RAM issues. by Steve Roberts on Nov 8, 2006 at 4:38:08 pm
[Steve Forde]"What happens is, OS X will not provide the RAM to AE, even though AE will report the RAM as being free. Hence your 3% usage. Shutdown and restart usually fixes this problem."
Steve, have you found that you can also clear RAM by opening the system drive in a window in the Finder (with all folder and file sizes visible), then waiting a minute?
Re: slow render RAM issues. by Dave LaRonde on Nov 8, 2006 at 4:57:04 pm
[Steve Roberts]"...have you found that you can also clear RAM by opening the system drive in a window in the Finder, then waiting a minute?"
Hmmm... hadn't heard of that particular trick; I'll give it a try.
But I KNOW that a restart or a shutdown cures a lot of ills, so the jury's out on my part. After all, why pussyfoot around with tack hammer on a wire brad when you can bash it really good 'n hard with a sledge hammer?
Re: slow render RAM issues. by Steve Forde on Nov 9, 2006 at 3:52:04 pm
To tell the truth - haven't tried that! Gonna give it a whirl and see if it works. Do you just literally double click on the system drive (thereby opening a window) and the inactive RAM gets flushed?
There is a command line call that you can use to flush it as well - but its strange as it is a disk check (nothing to do with RAM). I wonder if this call is used when the system drive is opened.....hmmm.
Re: slow render RAM issues. by Steve Roberts on Nov 9, 2006 at 5:11:26 pm
I found it on a message board recently, after seeking solutions for FCP's inability to purge RAM in the manner of AE. (there are those who say it's unnecessary to purge RAM in FCP, so maybe it's just me) :)
Yep! Just open the Macintosh HD window, make sure it's set to display file/folder sizes (maybe toggle it off/on to be sure), and wait. You do have to wait a minute, so maybe rebooting is faster ...?
