Mobility x1400 Query

[Ferger]

If this card can only use 128MB of shared system memory, why does it report
(and appear to be reserving) shared system memory of 763MB of my total 2GB?

 

[Augustus]

If this card can only use 128MB of shared system memory, why does it
report
(and appear to be reserving) shared system memory of 763MB of my total
2GB?

The card has 128Mb discrete memory and dynamically shares another 128Mb of
system RAM as needed. It can't and won't reserve 763Mb of system RAM in
XP.....where exactly are you getting these numbers reported? My guess is
your laptop is running Vista. Vista incorporates it's own memory sharing
scheme for RAM sharing but it's dynamically allocated and is not used unless
needed....Vista can allocated well over 750Mb of system RAM as needed. It
reports this as video memory, but it's basically never needs more than
another 128Mb or so and is used as system RAM.

 

[Ferger]

Augustus secured a place in history by writing:

The card has 128Mb discrete memory and dynamically shares another
128Mb of system RAM as needed. It can't and won't reserve 763Mb of
system RAM in XP.....where exactly are you getting these numbers
reported? My guess is your laptop is running Vista. Vista incorporates
it's own memory sharing scheme for RAM sharing but it's dynamically
allocated and is not used unless needed....Vista can allocated well
over 750Mb of system RAM as needed. It reports this as video memory,
but it's basically never needs more than another 128Mb or so and is
used as system RAM.

I think I understand that This is, indeed, a Vista machine, and the
figures are those which I see in the Radeon's properties tab, which say:

Total available graphics memory: 891MB
Dedicated Video Memory: 128MB
System Video Memory: 0MB
Shared System Memory: 763MB

Even from a clean boot, this machine reports typically 1.1GB of memory used
from the total 2GB, which is a bit disconcerting...