Does anyone deal with 4Gb ram?

On Thu, 10 Jul 2003 17:04:43 +0300, "shay" <shay-b@orbotech.com>
wrote:

> Hi There
> We building an image processor ....
>
> Our Hardware running in kernel mode !( Frame grabber that using 3-4 Gb
> memory)
> The problem is with assigning memory.

I think your question would get more success, and more accurate
replies, in a group related to device drivers.


But I'll try to answer:

Windows reserves part of the address space for user mode, and part for
kernel-only use (anything that runs in kernel mode can also access
"user mode" memory of course).

The default setup is 50/50: addresses 0 - 7FFFFFFF for user mode, the
kernel and device drivers start loading at 80000000. This way it
looks (to me) like any allocation request of close to 2GB or more can
do nothing but fail, in either mode, because there's no contiguous
unused address range that big.

There's a "/3GB" switch that can be used in boot.ini: this allows
certain applications (user mode) to use up to 3GB instead of 2GB.

http://www.microsoft.com/whdc/hwdev/...ae/paemem.mspx
could give you a starting point for more information.