8 gb ram to 32 bit operating system.
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you wont be able to use more than 3.25 gb of ram as said above by iyengar
if you want to use 8gb of ram you have to install 64bit OS
if you want to use 8gb of ram you have to install 64bit OS
PAE is there in windows as well, all it does is instead of using 32 lines, it uses 36 lines for addresses but the benefit is only visible for application which are build with PAE aware switch. All normal applications will still see same limitation.Prole73 said:
So as every one said, there will be no use of 8 GB Ram on your 32 bit OS, but if you *are sure* that your usage is that heavy, you can install a 64 bit OS and get benefit of extra RAM.
P.S.: No PAE switch at compile time, in fact an application should use 'Address Windowing Extensions" API to access this large Memory. Thanks to Blufox for pointing it.
--- Updated Post - Automerged ---
A little updateiyengar said:
, it varies from 3 to 3.5 based on your mother board and hardware installed. My Ep45-UD3R gives 3.5 to 32 bit windows XP.intel dg31 PR - 3.25
G41-m-es2l - 3
The RAM works when an address is assigned to it... (Like seat numbers given to us during our exam)
To assign the address, First the processor and the motherboard should be capable...
All of the Processors and motherboards after Pentium D support it...
So you can see the attached memory fully in your BIOS.
But when applications want to use the physical, they have to use it through Memory Management (In Windows).
And as 32Bit is not capable of addressing more than 4GB of RAM, So the Virtual memory usable will be only 4GB, even though the rest already addressed by the processor.
Hope this clears everything...
To assign the address, First the processor and the motherboard should be capable...
All of the Processors and motherboards after Pentium D support it...
So you can see the attached memory fully in your BIOS.
But when applications want to use the physical, they have to use it through Memory Management (In Windows).
And as 32Bit is not capable of addressing more than 4GB of RAM, So the Virtual memory usable will be only 4GB, even though the rest already addressed by the processor.
Hope this clears everything...
adi_vastava said:
How do you build applications to be PAE aware? 0_O
Applications are never built with PAE awareness, they do not even know about PAE.
A kernel is modified to know about PAE, not the applications.
If you using Linux, get a pae-enabled kernel.
On windows I think server edition has PAE support.
HTH
Yeah I was not clear, let me try my bit again,blufox said:
You modified your OS to support PAE, now it can see more than 4 GB of Ram. correct.
But your application was built with 32 bit pointers, which still can not go beyond its limit, right?
So your application is still limited in terms of address space. than the benefit will be in terms of less page in/page out and will not have any effect on address space available for a process.
Which Surly means your application need to do something if it want to avail any benefits of huge memory made available by PAE.
Though Yes, I was wrong with the switch, confused this with large address aware switch (used to increase user mode space to 3 GB)
.What an application need to do is to use "Address Windowing Extensions" API, check this for details Address Windowing Extensions (Windows)
on windows AFAIK, 2k onwards all 32 bit OS supports PAE though there could be different memory support. No info on linux.
(last post updated with this information)
I hope I am clear this time. :ashamed:
Both client and server editions of Windows support PAE, but client editions don't use PAE to enable more than 4 GB RAM (and actually a bit less based on how devices are mapped by your chipset - between 3.25 and 3.5GB). As mentioned above, your application will still not get more than 3 GB of RAM to itself (if it is compiled appropriately, the default is 2 GB). It can use AWE to be able to access more RAM than that, but few applications provide support for that.
Your best bet is a 64 bit OS and a 64 bit application. You could run a 32 bit application, but then it would again be limited to 3 GB RAM (unless it used AWE, and that is rare and less efficient than a native 64 bit application)
Your best bet is a 64 bit OS and a 64 bit application. You could run a 32 bit application, but then it would again be limited to 3 GB RAM (unless it used AWE, and that is rare and less efficient than a native 64 bit application)