Linked by Thom Holwerda on Wed 5th Jan 2011 22:09 UTC
Windows And this is part two of the story: Microsoft has just confirmed the next version of Windows NT (referring to it as NT for clarity's sake) will be available for ARM - or more specifically, SoCs from NVIDIA, Qualcomm, and Texas Instruments. Also announced today at CES is Microsoft Office for ARM. Both Windows NT and Microsoft Office were shown running on ARM during a press conference for the fact at CES in Las Vegas.
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RE[6]: enough bits?
by malxau on Thu 6th Jan 2011 22:18 UTC in reply to "RE[5]: enough bits?"
malxau
Member since:
2005-12-04

"A Windows client SKU won't address more than 4Gb of physical memory. This means that applications can't use those physical pages either.


This is simply wrong.
"
Have you looked at my Bio? I work on Windows full time. If you want me to go over memory management, I can bore you to tears, but it's very unlikely that you'll be able to dismiss me that easily.

Firstly, here's the page that describes limits on physical addressing:
http://msdn.microsoft.com/en-us/library/aa366778(v=VS.85).aspx#physical_memory_limits_windows_7

Second, this section might be helpful (the part that talks about how PAE, /3Gb, and AWE are related and not related):
http://msdn.microsoft.com/en-us/library/aa366796(v=VS.85).aspx



That's all well and good, but it's still subject to the physical memory limits described in the link I gave above. See the part where it says "The physical pages that can be allocated for an AWE region are limited by the number of physical pages present in the machine, since this memory is never paged..." What this link really shows is that a single process, which has 2Gb of VA, can use greater than 2Gb of physical pages on a 32-bit client system. It cannot use more than 4Gb of physical pages, since that's the absolute maximum the client system will ever use.

It also shows that MS' implementation of AWE requires physical pages and is therefore unsuitable to extend addressing. On client systems it's only useful to get from 2Gb to (some value less than) 4Gb.

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