Will Microsoft Windows 7 Ultimate 32-bit utilize 8GB of RAM?

October 25, 2009 7:08 AM

Just for confirmation, will Microsoft Windows 7 Ultimate 32-bit utilize 8GB of RAM?

I already own a laptop with windows vista ultimate 64-bit with 8GB installed. I just want to confirm if Microsoft Windows 7 Ultimate 32-bit will utilize 8GB of RAM or I should buy a 64-bit version.
I am not welling to buy an upgrade version but a full retail version.

posted by omaralarifi to computers & internet (9 comments total)

You have to get the 64-bit version. Unlike Vista, however, I believe that the retail version comes with discs for both the 32-bit and 64-bit versions — I can't attest to this personally, but I've read it in a few different reviews.
posted by jaffacakerhubarb at 7:13 AM on October 25

I just bought a couple of copies of Win7 and I can confirm that there are both 32 and 64 bit install disks in a single retail package.
posted by crazycanuck at 7:25 AM on October 25 [1 favorite]

It will not. In fact, I'm pretty sure there is not a single 32bit OS that can address more than 4gig of Ram. (It's a limitation of the way 32bit architecture addresses memory)
posted by jmnugent at 7:50 AM on October 25 [1 favorite]

This is among the main reasons I want to get to 64bit Win7. I put an extra 4 gig of RAM in my PC 2 years ago. Only now did I realize that XP hadn't been making use of them the entire time. The salesman from the RAM wholesaler sure didn't explain that on the phone.
posted by meadowlark lime at 8:03 AM on October 25

Here's a very detailed article from Microsoft about the memory limits in various versions of Windows. Short answer, all 32-bit Windows 7 versions are limited to 4 GB.

The 64-bit versions of Windows 7 almost all support 8 GB (the "starter edition" being limited to 2 GB). 64-bit ultimate, in particular, supports 192 GB. If you are planning to use all this memory for one application, it will have to be a 64-bit version as well. 32-bit applications only get to use 2 GB at the most, even on a 64-bit OS.

Some 32-bit server versions of Windows (2008, 2003, 2000) can address more than 4 GB using Physical Address Extension features of the hardware. 32-bit applications running on those can even use more than 4 GB for one application if they support Address Windowing Extensions. PAE and AWE are kind of messy to program for, though, so they are not used outside of the windows server OSes and server applications like SQL Server.
posted by FishBike at 8:06 AM on October 25

It will not. In fact, I'm pretty sure there is not a single 32bit OS that can address more than 4gig of Ram. (It's a limitation of the way 32bit architecture addresses memory)

There's no true technical reason why this can't work; 32-bit Linux and Mac OS support more than 4 gigs just fine in 32 bits. They use a technique called Processor Address Extension, or PAE mode, which lets them address up to 64 gigs of RAM. Each individual process is still limited to 2 or 3 gigs (depends on the OS and settings), but you can run a whole lot of processes. OS X can even run 64-bit binaries on its 32-bit kernel; I don't know if Linux can or not.

XP, as it originally shipped, also supported this mode, but Microsoft turned it off in either SP1 or SP2, because apparently customers were having driver trouble. The Microsoft universe is full of crappy driver writers that didn't take high memory into account, and this was causing instability for at least some customers, so ALL 32-bit XP customers are now limited to about 3GB of useful space. Their 32-bit server OSes still support PAE mode.

Probably to hurry 64-bit adoption, Vista 32-bit maintains the 4GB limitation on physical RAM. You must go 64-bit to get more.

If there's an upside, it's that we won't have this problem again for at least forty years. :)
posted by Malor at 9:24 AM on October 25

Malor is correct and 32bit versions of MS's Server Operating Systems did support this.

Besides speeding 64bit adoption it cuts down on their testing matrix quite a bit.
posted by mmascolino at 1:27 PM on October 25

Malor may be correct but it isn't the question asked. Do you need to go 64 bit to use that 8G of RAM under Windows 7? Yes, you do.

I have retail packages of Win 7 Pro and Win 7 Home Premium, both upgrade editions, and both include 64 and 32 bit DVDs.
posted by chairface at 2:23 PM on October 25

If there's an upside, it's that we won't have this problem again for at least forty years. :)

And once we've had it one more time, I think the adoption of 128-bit addressing for RAM is likely to be a permanent fix.

The mass of a proton is of the order of 10^-27kg, i.e. roughly 2^-81kg. If we're using 128-bit addressing, and limiting ourselves to 1kg of RAM per personal computer, we'd need to store 2⁴⁷ bits per proton to exceed the available addressing range. Even given rapid development in quantum computing, that strikes me as implausible.

Might be waiting a few years for hibernation and wakeup, too :-)
posted by flabdablet at 5:19 PM on October 25