Users occasionally get “Out of Memory,” or “Low Resources,” messages, or something similar, when doing video editing. Usually, the first thought is “hey, I have a lot of RAM. What’s the deal here?” Well, RAM is part of the system’s memory, but is not the whole story. There is also Windows Virtual Memory, the Page File. This is HDD (Hard Disk Drive) space that serves as an overflow for RAM usage, and really comes into play with intense operations, like video editing, where everything cannot fit into RAM. Having a 64-bit OS with 64-bit programs and 24GB of fast RAM will diminish the need and use for Virtual Memory, but until all of us are running super computers with only 64-bit OS’s and programs, it is very important.
Now, the Virtual Memory is setup upon installation of the OS, and it defaults to being placed on the system drive, C:\, having Windows dynamically manage it (expanding and contracting it, as is needed, but more on this later), and a general size, based on the detected, installed physical RAM. For most general computing, that works fine. For video editing, things can be improved upon.
In XP-Pro, one would change these default settings by going to Control Panel>System>Advanced>Performance>Advanced>Change. The location of the settings will probably be similar in other versions of Windows, but one might have to poke around a bit to get there.
Now, let’s talk about some better settings. First, the location, will probably depend on a couple of factors. If one only has one physical HDD, then it’s a no-brainer. It will be placed on C:\. If one has two physical HDD’s, then it might be better to locate it on D:\, but one should test to see if there are any performance gains. If one has 3, or more physical HDD’s, then I would definitely locate it on the least used HDD. The idea is to spread the load amongst as many HDD’s, as is possible. With C:\, you have the OS and the programs fighting for reads and writes. If you can move the Page File to another HDD, you cut down on the fighting, however, if you move it to the HDD with your Project files, your Scratch Disks and your media, there might still be some struggle for HDD usage. If you can locate it away from the OS, the programs, the Projects and Scratch Disks and the Media, you will be doing well. Also, as the Page File is created at boot up, if you can get it onto a seldom used HDD, then you benefit in that it will be placed at the head of that HDD, which is faster, and when you defragment, it will be easy to keep this space clean and defragmented. Because the management of the Page File also plays a role here, that is our next subject.
With a dynamically managed Page File, the OS must anticipate the size required, and be one step ahead of the program in getting it expanded in time. This takes CPU cycles and requires a lot of monitoring by the OS. Yes, when no longer needed, the OS will contract it, but unless one has very limited HDD space, this really saves nothing, and for video editing, HDD space is extremely important, and one should not have to worry about a constant, large Page File. By being statically managed, one also gets the same size Page File written at boot up, making that defragmenting easier.
As to the size of the statically managed Page File, the old thinking was about 2.5x the installed physical RAM, meaning that if one had 4GB RAM, the Page File should be about 10GB. With newer OS’s, and especially 64-bit with much more RAM, that is not necessary, and a more 1:1 ratio would be fine - maybe even overkill. For 12GB RAM, a 10GB Page File is probably adequate, but if one gets Memory, or Resource messages, just bump it up to 12 - 14GB.
If one is receiving “Out of Memory,” or “Low on Resources,” the Page File should be one of the first things considered. The next would be the possibility of a bad stick of RAM.