What I mean is that I create a driver installation package using EMGD 1.5 and after installing it on a Windows 7 target (in XPDM mode), I open the Task Manager on the target and I see that more than 300 MB of memory are used by the driver compared with the standard VGA driver.
And this is not the case if I install the same driver on a Windows XP target (same hardware).
Does anyone have a clue for this memory usage difference ?
Sorry about that.
It may be related to the XPDM driver model. I saw only this small blurb on MSDN
Beware that setting this registry key value on computers using XPDM drivers will cause applications to use a large amount of additional video memory, decrease the performance of 3-D rendering, and has the potential to introduce rendering errors and stability problems.
The registry key being
But this assumes this is even relavent to the driver (I haven't fired up the drives under win 7 yet to confirm).
Maybe this is a place to start.
I think we have a few things going on here.
1. Windows 7 does a MUCH better job of reporting system usage statistics than XP did. We have seen a much improved CPU usage and other resources tracking that MS implemented in the Win7 kernel.
2. The driver DOES allocate quite a bit of memory for use by the graphics engine in both XP and Win7- these include the frame buffer and other graphics memory. This is part of the Unified Memory scheme used by integrated graphics. The driver itself is the same size between XP and WIn7 and the amount of memory it allocates is the same also. The reserved memory is required for the driver to be able to do graphics and 3D and such. If you are not doing rendering and other 3D functions, you can go into your BIOS settings and reduce the graphics aperture setting to reduce graphics use, but you WILL impact 3d performance and video playback capability.
3. XPDM under Win7 may have different reporting "rules" than on XP but that is just conjecture- only Microsoft would know for sure.
I would not worry- it sounds like you have 256MB allocated for graphics and the rest is driver and other buffers.
We will take a look at the memory usage reporting and put out an FAQ if needed.
Hope this helps, Kirk