VRam reduced from 128M(XP) to 64M(Vista)!!!!!

[nio_7]

I have recently upgraded from windows XP Media Center to Vista.
My laptop is a VGN-FE31H with a GeForce Go 7400.
In Windows XP, in display adapter properties, I was having: 128MB VRam + 128MB from shared ram that was giving me a total of 256MB Video memory.

On Vista now, i was amazed to see that the VRam has changed to 64MB + 271MB from shared ram that is giving me a total of 335MB of Video memory.

How did that happen??? It's not possible!! As far as i know the Vram is hardware fixed on the Graphics card!!! How can this change??!! I don't get it...

Any idea on this???

[Blencogo]

Unfortunately Vista is right - nVidia were deliberately vague about dedicated memory if you visit their website.

Your GPU has 64 MB of its own hardware DDR memory on the GPU chip. With XP your system could DEDICATE memory from RAM to the GPU and the Go 7400 has taken 64MB DEDICATED from RAM. This means Windows cannot use it because it is ring-fenced for graphics. So nVidia call the 64MB on the chip plus 64MB from RAM as 128MB of DEDICATED memory. In addition the Turbocache can use an additional 128MB from RAM if this is available. If you read the literature it says the 7400 can use up to 256MB.

I think this was a deliberate deception.

Vista tells it like it is - you have 64MB DEDICATED on-chip memory but Vista will not allow you to ring-fence any RAM at all. Vista knows best and will allocate all the available RAM to give the best performance. With XP the DEDICATED memory was often wasted when the system could have used it to better advantage than the GPU. Vist is very much the 'nanny state' OS.

[nio_7]

Thank you so much for you answer!!
You solved this mystery to me, so now i know...
Thanks.