getting the most out of RAM with AE CS3

[Kevin Camp]

enable multiprocessing in ae (preferences>multiprocessing) if you haven’t already.

if you have a dual g5, then then the default values for the max ram cache setting should be fine, you may be able to up the max ram cache to around 67-70%, but i’m not sure it will be that big of a benefit.

if you have a quad g5 (the dual dual-core), then you’ll probably want to change the max ram cache to around 33% to get all 4 cores rendering, this should give around 1gb of ram to each core.

in either case, as you make changes to the max ram cache, you can go to the multiprocessing pref and see how many ‘additional cores’ will be used for rendering based on the cache settings you’ve made.

also, disabling opengl for previews (preferences>previews, then uncheck the opengl box) will allow you to use multiprocessing for previews too (opengl rendering is not compatible with multiprocessing, so, if enabled, opengl will override the multiprocessing for ram previews). in most cases i think you’ll find multiprocessing will beat out opengl for preview renders, so don’t feel like your missing out on some cool opengl benefit.

Kevin Camp
Senior Designer
KCPQ, KMYQ & KRCW

[Kevin Camp]

well… i’ve just read that you don’t want to increase the max ram cache setting beyond 60% ‘unless necessary’. i’m not sure when it’s ‘necessary’, but based on that you may not want to increase that cache setting to 67-70% as i had mentioned (if you had a dual g5).

if you have a quad g5, i also just read a note (by a guy who wrote the ae manual) that multiprocessing will work best with 2gb of ram per core… he went on to say that you may get better performance by restricting the number of cores available to match the 2gb per core ratio. so you may be able to get better performance by doing the following steps to restrict ae to using just 2 cores (again, if you have a quad):

1. Quit After Effects.
2. Open the After Effects text preferences file, Adobe After Effects 8.0 Prefs.txt, located in the following folder:
   Mac OS: Users//Library/Preferences/Adobe/After Effects/8.0
   Windows XP: C:\Documents and Settings\\Application Data\Adobe\After Effects\8.0
   Windows Vista: C:\Users\\AppData\Roaming\Adobe\After Effects\8.0
3. Find the [‘MP’] section.
4. Change the “MaxNumberOfProcesses” value to “2”.
5. Save and close the preferences file.

Kevin Camp
Senior Designer
KCPQ, KMYQ & KRCW

[Kevin Camp]

[Kevin Camp] “i also just read a note (by a guy who wrote the ae manual) that multiprocessing will work best with 2gb of ram per core… he went on to say that you may get better performance by restricting the number of cores available to match the 2gb per core ratio.”

well i decided to test this one…. i have a 4-core macpro with 4gb of ram, i restricted the core to just 2 and i found that it render slower than with all 4 cores… but only about 20% slower. so i pulled 2gb from another system and threw it and restricted ae to 3 cores (with 6gb ram) and ae rendered my benchmark file at just about the same speed as with 4 cores.

so there maybe something to the 2gb per core sweetspot, but it doesn’t seem to make the performance boost that was suggested by the info i read earlier…

Kevin Camp
Senior Designer
KCPQ, KMYQ & KRCW