Quote:
Originally Posted by Bitter
i see 3GB of ram in task manager on xp pro sp2  |
Do you see it in the Physical Memory part? -
Where are we going, and what's with the handbasket? : Who ate my memory?
If you follow the TechNet article into the driver compatibility section, you'll see this paragraph "To constrain compatibility issues, Windows XP Service Pack 2 includes hardware abstraction layer (HAL) changes that mimic the 32-bit HAL DMA behavior. The altered HAL grants unlimited map registers when the system is running in PAE mode. In addition, the kernel memory manager ignores any physical address above 4 GB. Any system RAM beyond the 4 GB barrier would be made unaddressable by Windows and be unusable in the system. By limiting the address space to 4 GB, devices with 32-bit DMA bus master capability will not see a transaction with an address above the 4 GB barrier. Because these changes remove the need to double-buffer the transactions, they avoid a class of bugs in some drivers related to proper implementation of double buffering support."