The main instance of After Effects CS4 is limited to a little less than 4GB of RAM.
But if you have a multiple core system and enable the Render Multiple Frames Simultaneously feature, it will spawn a background instance for each core. Each of these background instances can use up to 4GB itself. So, if you had a quad core system, actually 8GB of RAM is not that much.
For more information, see Memory and multiprocessing preferences in After Effects Help.
... and in addition to what was said before: A 32bit operating system is simply the wrong one on any machine with more tha 4GB RAM. You will need Vista 64bit to even max out the theoretical 4GB ceiling for a single instance of AE.
After Effects is limited to a theoretical maximum of 3GB of RAM per core. In practice, you should probably use no more than 2GB of RAM per core and probably no more than 1.2GB of RAM for your RAM Cache. The more RAM you allocate for the cache the higher the chance of getting render errors.
If you have a machine with multiple processing cores and a 64-bit OS you can enable Multiprocessing in After Effects's preferences. This will provide a separate RAM cache for each core. For example, if you are working on an 8 core system, at 2GB per core, you could have 16GB of RAM installed on your machine (2GB x 8 cores). With a RAM Cache of 1.5GB per core, 12GB of RAM would be required to render on each core simultaneously (1.5GB x 8 cores).
So without knowing the details of your system, I would give this a try:
- lower your Maximum RAM Cache to between 50-60%
- enable multiprocessing
See if that makes a difference.
Elaine, your answer includes some items that are factually incorrect or misleading.
> After Effects is limited to a theoretical maximum of 3GB of RAM per core.
No. The theoretical maximum is 4GB per core.
"The operating system imposes certain limits on the amount of memory that an application can use. After Effects on the Mac OS X operating system can use up to 3.5 GB of RAM, although only about 3 GB is actually available to the foreground application, because Mac OS X uses approximately 500 MB to load the user interface libraries. After Effects on 32-bit Windows operating systems can use up to 3 GB of RAM; however, to use more than 2 GB in After Effects, you must configure Windows XP or Windows Vista appropriately.... After Effects on 64-bit Windows operating systems can use up to 4 GB of RAM with no special configuration."
(See "Memory usage and storage".)
Your use of the term "RAM cache" is also misleading. Whether you have Render Multiple Frames Simultaneously on or not, the foreground process stores frames for RAM preview in a RAM cache. There is not a separate "RAM cache" for each of the background processes.
Also, you tell this person to change their RAM cache setting to a certain percentage. The original poster is using After Effects CS4. Only After Effects CS3 and earlier have the RAM cache exposed s a percentage.
> If you have a machine with multiple processing cores and a 64-bit OS you can enable Multiprocessing in After Effects's preferences.
The Render Multiple Frames Simultaneously feature is not dependent on a 64-bit operating system. Yes, it works much better on a 64-bit operating system, but you can see performace gains with only two processors on a 32-bit operating system.
I'm trying to maximize available RAM for AE CS3 using Intel Centrino Duo processor with 4gb installed memory. Should I restrict to 3 gb or go for all four? What is downside of configuring for all 4? When reconfiguring BOOT TAB, do I configure RAM at 3072 and select 1 processor? or 2 processors? Can I configure 4096 RAM and two (2) processors? Is this a recommended configuration or will it rob performance from other processes? Is this 'reconfig' really irreversible as the Windows pop-up claims when selecting 'make all boot settings permanent'?
Sorry, failed to mention OS is Vista 32.
I apologize for the confusion Todd. I stand corrected.