Accessing more than 4gb from a 32-bit OS.

Hes probbly used the PAE hack from server 2003 :rolleyes:
Utterly usless though as the OS STILL cant address more than 4GB anyway, even if it can now see it all.
And Bledd is totaly correct on the whole 2GB App thing too.
 
I was under the impression that PAE allows a 32 bit OS to address significantly over 4gb in total, though each application is limited to 2gb. I'll check this.

Couldn't find the source I had in mind, but Google is pretty insistent that 32 bit ubuntu server has it enabled, 32 bit ubuntu desktop doesn't, and that it works much as bledd says. Found a few references to the effect that "ubuntu using pae is stable, unlike *cough* windows *cough*", but given ubuntu has a slightly odd definition of stability take that with a pinch of salt.

There's also a piece of software for 32 bit windows which can create a ramdisk in the unallocated space. It was very unstable for me, but did work between crashes.
 
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Using more than 4GB of RAM under 32-bit is technically possible using PAE, but the Windows kernel has a 4GB limitation. The only way to get around it is to remove the limitation and persuade Windows to load an unsigned kernel. Given that your colleague doesn't seem to know how bandwidth works, I'd doubt he has the knowledge to modify the Windows kernel :p
 
Here we go 32 bit with PAE enabled it sees 4Gig but only use 3.3Gig
win.jpg
 
JonJ678 said:
I was under the impression that PAE allows a 32 bit OS to address significantly over 4gb in total, though each application is limited to 2gb. I'll check this.
Click to expand...

Yep, that's right. Physical Address Extension is enabled by default on Windows XP Service Pack 2 and later operating systems so they can "technically" address more than 4GB of RAM. However, the reason they don't is due to a licensing restriction on consumer based operating system which Mark Russinovich discusses below:

Mark Russinovich said:
Windows Client Memory Limits

64-bit Windows client SKUs support different amounts of memory as a SKU-differentiating feature, with the low end being 512MB for Windows XP Starter to 128GB for Vista Ultimate and 192GB for Windows 7 Ultimate. All 32-bit Windows client SKUs, however, including Windows Vista, Windows XP and Windows 2000 Professional, support a maximum of 4GB of physical memory. 4GB is the highest physical address accessible with the standard x86 memory management mode. Originally, there was no need to even consider support for more than 4GB on clients because that amount of memory was rare, even on servers.

However, by the time Windows XP SP2 was under development, client systems with more than 4GB were foreseeable, so the Windows team started broadly testing Windows XP on systems with more than 4GB of memory. Windows XP SP2 also enabled Physical Address Extensions (PAE) support by default on hardware that implements no-execute memory because its required for Data Execution Prevention (DEP), but that also enables support for more than 4GB of memory.

What they found was that many of the systems would crash, hang, or become unbootable because some device drivers, commonly those for video and audio devices that are found typically on clients but not servers, were not programmed to expect physical addresses larger than 4GB. As a result, the drivers truncated such addresses, resulting in memory corruptions and corruption side effects. Server systems commonly have more generic devices and with simpler and more stable drivers, and therefore hadn't generally surfaced these problems. The problematic client driver ecosystem led to the decision for client SKUs to ignore physical memory that resides above 4GB, even though they can theoretically address it.
Click to expand...

Pushing the Limits of Windows: Physical Memory

The bottom line is if you would like your system to be able to address 4GB of RAM or more, simply migrate over to Windows x64 which really isn't a problem these days.
 
PAE lets you use more than 4Gb, however, MS restrict the total depending on the OS version

http://msdn.microsoft.com/en-us/library/aa366778(VS.85).aspx

You'll see there that some 32-bit versions of Server 2008 and 2003 will support up to 64Gb memory whereas others are only 4Gb.

The OP does not state what OS is being run, it could be a server OS - perfectly reasonable for someone to have access to a Technet or MSDN sub, or indeed a non windows OS
 
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