Chapter 4/ System Briefing
Land of the Lost (Memory)
One thing that the previous exainples fail to mention is that not alt of the
physical memory that's reported is usable. This is because Windows also
reserves space for device memory. You can see this by running the msinfo32
connmand and selecting the System Summary root node. On a system with 4
GB of physical memory, you might see something like;
Total Physical Memory: 4.00 GB
Available Physical Memory:3.50 GB
Ah ha! You can take a closer look at these reserved regions using msi nfo32 by
selecting the Memory child-node underneath the Hardware Resources node
(Figure 4.2).
� Synlem InformatiiM
Ete gdc Hetp
-101 Ml
System Summarj'
B Hardware Resources
Conflicts/Sharing
DMA
Forced Hsrdivare
VO
RQS
Memory
K Components
K Sofbvare Environment
Resource
Devke
Status —
OxfeOOOOOO-OxFBFFf FFf tnUJ(Rl 82801 PCI Bridge ■ 2443 OK
OrfCOOOOOO-OxFDFFFFFF Ifltc)(RJ 82S5SPM Processor to AGP Coirtroller - OK
OxfCOOOOOO-Oxf DFFFFFF Standard VGA Graphics Adapter OK
Otf0000000-0*F3FFFFFF inteJ(R) 82355PM Processor to agp Controller - _. OK
OxfOOOOOOO-OxFSFFFFFf Standard VGA Graphics Adapter OK
OxESOOOOOO-OxEFFFFFFF irttel(R) 82855PM Processor to agp coMroller - OK
OxFAFEFSOO-OxfAFEFfFf Teas Enstruments 1S94 OHCl Compliant Host C~ OK
0)�AFEdQW-0xF.«FEeFFF Texas Enstruments OHCI Compliant Host C.~ OK
Orf4Fff800-0*f4FfF4fF Intel(r) S2801&e/06M AC 'S? Audio Controller OK
Otf4FFF400-OxFdFFF4FF Iflt«1(r) 82a01[>B/DBW AC 97 Audio Controller OK
OxFBFFfOOO-OxFBFFFFFF Texas Instruments PCI-7&10 CardBus ContrgDer OK
�1"..........L_. . I "■
find atiati I
r" iearch selected category
Find
£,tose find
only
r Sea£ch category names on!)'
Figure 4,2
How Windows Uses Physical Address Extension
The amount of physical memory that can be accessed by Windows depends
upon the version of Windows, the underlying hardware platform, and some¬
times on how Windows is configured (see Table 4.1).'
1. http://msdii.microsoft.com/en-iis/library/aa366778%28v=VS.85%29.aspx.
118 I Parti