I asked an almost identical question in a thread over at HV20.com.

I am aware that WinXP will only see about 3GB (3.25 in my case) but like you, Vegas sees only 2 GB. As does After Effects.

Turns out that Windows programs can only use 2GB, regardless of how much is installed.

This link may be helpful:

http://msdn2.microsoft.com/en-us/library/ms791558.aspx

thanks! And here it says (almost the same link as above):
http://www.microsoft.com/whdc/system/platform/server/PAE/PAEmem.mspx

"The /3GB switch allocates 3 GB of virtual address space to an application that uses IMAGE_FILE_LARGE_ADDRESS_AWARE in the process header. This switch allows applications to address 1 GB of additional virtual address space above 2 GB."

has anyone tried this with Vegas Pro 8?

Sami

Sounds like it's working as expected for a 32-bit application running on 32-bit windows.

Rob

I don't think that Vegas was compiled for it. PPro uses it, which means in 32-bit Windows it can use that much more page file, and maybe even RAM if it's available. Remember that the OS and lots of services still need a slice of your 2.9 GB of addressable RAM.

In 64-bit Windows PPro has more of a chance to actually use 3GB of RAM if your entire 4 GB (or more) is addressable. Vegas too is helped because it can use more RAM instead of leaning on the page file, just not as much. The way Windows works, you never really avoid using the page file, and Virtual Address space generally includes RAM and Page file.

Rob

Thanks everyone, Ill be fine with this, Vegas seems quite fast anyways.

Sami

You might not really want Vegas using more of the page file, or forcing other apps to do so. :-)

Rob

For the most part, every new version of Vegas seems to be more efficient with memory use. I only have a dual core. I wonder if Vegas running on a quad machine uses more RAM (due to concurrent processing).