AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |
Back to Blog
How much ram can windows xp use2/21/2023 Some if it may be real memory, some if it may be virtual memory on the hard disk. Your processes will always have this much "virtual" address space. This has nothing to do with the process address space, which is always either 2GB or 3GB depending upon the /3GB switch you pass to the kernel on boot up. XP SP2 prevents that re-mapping, so hiding more of your memory, from both the kernel and userspace. So, to summarise, XP SP1 does not support the no-execute bit, and therefore does not need to turn on PAE if the memory size 4GB, exposing more of your real memory for use both by the kernel and userspace, but with the risk that badly written drivers might not be able to use the re-mapped IO addresses. Microsoft determined that this was not the case, and modified the way that PAE works so that the memory mapped IO is all under 4GB, and badly written drivers are safe to use. What this means is that all drivers that need to access the memory mapped IO, through DMA for example, would have to understand PAE in order to work correctly with SP2. There are reasons for this that I won't go into because it's not relevant. With the introduction of the No Execute Bit for Data Pages in SP2, Windows XP now runs in PAE mode (Page Address Extension, to enable the addressing of >4GB memory) even when running with 4GB or less. Basically the memory mapped IO *is* the problem, and it's equally a problem on Intel and AMD motherboards.
0 Comments
Read More
Leave a Reply. |