4GB in 32-Bit O/S

[Zorg]

BEST WAY: Try to plan ahead by at least reviewing a motherboard's
Qualified Vendor List ("QVL") which should list all compatible DIMM modules.
Then, read that motherboard's User Manual, to search for any special
conditions/restrictions that are known to modify or limit operational performance.

Thanks for the Kudos.

I'm going to have to start calling it the QVL I usually just say check the compatibility page.

You gave all good advice as usual. My only concern about going to the manual or the manufacturer about any problems with using 4 slots is that they aren't really forthcoming with the information. I don't know this for sure because I have always thought that 4G is a waste, at least for me, but I have never seen any manual or manufacturer website address 4G, other that to say you can use all 4 slots.

You probably need to do what you did, which is get down in the trenches and root through unbiased information to get at the truth.

 

[jaydub868]

Well, as long as no harm is done by using 4GB's, and given how cheap ram is now, I think I'll go with 2x2GB's sticks of DDR2 800Mhz, downclocking to 667 to run it synchronously with the FSB. I may want to try Vista 64 at some point, and four sticks can cause problems, I've heard. Thanks everyone for your help. Didn't think this thread would go on for so long!!!

 

[notherdude]

Well, as long as no harm is done by using 4GB's, and given how cheap ram is now, I think I'll go with 2x2GB's sticks of DDR2 800Mhz, downclocking to 667 to run it synchronously with the FSB. I may want to try Vista 64 at some point, and four sticks can cause problems, I've heard. Thanks everyone for your help. Didn't think this thread would go on for so long!!!

Good call, IMHO. RAM is too cheap to worry about it. Might as well have that luxurios headroom. And 2 x 2 is a good way to go. I have 4 x 1 on an ASUS P5B deluxe and there is a problem with 4 sticks installed. My sound card is whack on warm boots. If I turn off the PC before re-starting then no (apparent) problems. I have this in Vista 32 and 64 and XP 32, so it must be the mobo and not a particular OS.

 

[Mondoman]

Paul, just a note not to equate PAE with being able to address more than 4GB of RAM.
Remember that PAE is often *enabled* by default on Win XP and Win Vista, as the XD (execute disable) functionality is implemented using PAE. However, the consumer Windows OSs still have a 4GB memory addressing limit, so PAE cannot be used to address higher memory addresses on those systems.

 

[Scotteq]

I may want to try Vista 64 at some point, and four sticks can cause problems, I've heard.

jaydub - Install with 2GB. Then while you do your updates, driver installs, and 500 reboots, reach out to http://support.microsoft.com/kb/929777/en-us and grab/install the update. Reboot with 2GB installed. Then install the other 2GB of RAM at your convenience.



*****

Paul: As a matter of pragmatism, you might want to think twice about using "PAE" and "Microsoft" in the same sentence. At least on a consumer level.

Check: http://support.microsoft.com/kb/929605/en-us

"To avoid potential driver compatibility issues, the 32-bit versions of Windows Vista limit the total available memory to 3.12 GB"

and

"DEP may cause compatibility issues with any driver that performs code generation or that uses other techniques to generate executable code in real time. Many drivers that experienced these issues have been fixed. Because DEP is always on for drivers that are on 64-bit versions of Windows, these drivers typically experienced compatibility issues. However, there is no guarantee that all drivers have been updated to fix PAE-mode-induced compatibility issues. However, there are few drivers that use these techniques. DEP alone does not typically cause driver compatibility issues.

{BOLD text provided by me for emphasis.}

And - If you enable PAE:

Some drivers might not load if PAE mode is enabled because the device might be unable to perform 64-bit addressing. Or, the drivers might be written with the assumption that PAE mode requires more than 4 GB of memory. Such drivers are written with the expectation that the drivers will always receive 64-bit addresses in PAE mode and that the driver or the device cannot interpret the address.

Other drivers might load in PAE mode but cause system instability by directly modifying system page table entries (PTE). These drivers expect 32-bit page table entries but receive 64-bit PTEs in PAE mode instead.

The most common PAE compatibility issue for drivers involves direct memory access (DMA) transfers and map register allocation. Many devices that support DMA, typically 32-bit adapters, cannot perform 64-bit physical addressing.

Yes, PAE enables 4GB and greater. But Microsoft have basically decided they already have have (and certainly are getting blamed for...) more than enough issues with badly written third party drivers causing problems. Therefore they don't officially support PAE in 32 bit OSs because very few vendors write the code needed to use it.


Scott

 

[dengamle]

So basically they just ignore the upper part of the address when running in pae mode, to fix the dma issue.

somewhere they also blame the device itself for not being able to do 64-bit addressing. I don't see that change just because you install the 64-bit counterpart, so i think that argument is a little weak

 

[dengamle]

Sorry to ramble, guys & gals, but the reality of consumer Windows XP/Pro
is that it is NOT REALLY a 32-bit OS, in reality, if 4GB of RAM cannot
be fully addressed by it:

2**32 = 4,294,967,296

Are you forgetting memory mapped IO? IO+RAM covers the 4GB address space

 

[Scotteq]

Sorry to ramble, guys & gals, but the reality of consumer Windows XP/Pro
is that it is NOT REALLY a 32-bit OS, in reality, if 4GB of RAM cannot
be fully addressed by it:

2**32 = 4,294,967,296

2**36 = 68,719,476,736

Paul - Not quite the issue: It's that the system needs to provide addresses for more than "just" the RAM, and only has 2**32 numbers available. If it were only RAM, it'd be a non-issue since there is 4GB available. But reality is that more than the DIMMS need to be communicated to, and there's only one pool of addresses. So the OS developers prioritize what's more important than what, and where the potential lack of addresses impacts users the least. In this case, not being able to 'see' that last bit of installed RAM only results in it not being used and an otherwise fully functional system. Not perfect, I agree. But certainly not bad.

PAE is available to get around the address limitation, but devices/drivers/programs then have to be coded to use it. Which they generally are not, since it's only necessary for a small subset of the marketplace. That same subset of the market also have the ability go to a 64 bit OS if they really need to, with the understanding they then need hardware/drivers for *that*. For the most part it's a non-issue from a consumer POV. And from a consumer POV, Vista 64 is available, runs plenty well enough despite reams of FUD to the contrary, and puts off the addressing problem for *quite* a long while.

 

[dengamle]

Applications don't need to be coded differently. Only if an application needs to address more ram than it's virtual address space allows, then it can use AWE.

If you multitask several heavy applications, they will take advantage of pae without knowing it

 

[rockyjohn]

> I have a Dell running in that configuration without any problems.


Have you confirmed that it is also running in dual-channel mode?

/

Yes

 

[dengamle]

The memory mapped io is not something microsoft made up, this is built into the hardware. The dedicated IO space is very limited, so they map everything into the memory address space instead

each address doesn't point to a 32-bit storage, it points to a 8-bit (or a byte) storage. So 2^32 addresses equals 2^32 * 8 bit = 4 giga byte

 

[notherdude]

Sorry to ramble, guys & gals, but the reality of consumer Windows XP/Pro
is that it is NOT REALLY a 32-bit OS, in reality, if 4GB of RAM cannot
be fully addressed by it:

2**32 = 4,294,967,296

2**36 = 68,719,476,736

Paul - Not quite the issue: It's that the system needs to provide addresses for more than "just" the RAM, and only has 2**32 numbers available. If it were only RAM, it'd be a non-issue since there is 4GB available. But reality is that more than the DIMMS need to be communicated to, and there's only one pool of addresses. So the OS developers prioritize what's more important than what, and where the potential lack of addresses impacts users the least. In this case, not being able to 'see' that last bit of installed RAM only results in it not being used and an otherwise fully functional system. Not perfect, I agree. But certainly not bad.

PAE is available to get around the address limitation, but devices/drivers/programs then have to be coded to use it. Which they generally are not, since it's only necessary for a small subset of the marketplace. That same subset of the market also have the ability go to a 64 bit OS if they really need to, with the understanding they then need hardware/drivers for *that*. For the most part it's a non-issue from a consumer POV. And from a consumer POV, Vista 64 is available, runs plenty well enough despite reams of FUD to the contrary, and puts off the addressing problem for *quite* a long while.

Or simply put MS 32 bit DOES address 4 gig.

Just not 4 gig of DIMM sticks.

 

[Scotteq]

Reads...

Rereads...

/school'd

Thank you kind sir!

 

[tonyp12]

So where are the 1536 MB sticks ??, so I can run them in dual channel mode.

If they start selling those 3GB pairs, I would get them.

Manufactures are you listing?

 

[notherdude]

Just get 2 2's, they still run in DC.

 

[Zorg]

Or just get 2 and let it eat.

 

[blucube]

I don't know how viable this is, or how late I am in posting in this thread about this issue. However I was running the 8800GTX with 4x1gb Crucial Ballistix PC-6400 sticks on Vista Home Premium 32bit. It would list it as 3.5gb, taking in mind of what we had already learned. However, I found that when I had 4gb installed it would wreak havoc upon my system causing me to format several times over. This could be because I was jamming all of that ram into it, or I learned later on the Crucial released the exact same stick with the exception that one was "low density" and the other was "high density". Even though there was nothing marketed differently, I found later that I had 2 of each, and I assume they didn't play well together. I ran memory tests on each dimm with each stick in every possible combination I could think of and never once received an error.

I was fed up having to format every few months so I finally took out the two high density sticks, and all has been well so far. With the exception I notice lag in the games I play is a little heavier opposed to when I stocked 4gb for some reason. I had switched to a 8mb cable connection to a 4mb cable connection. Though one would think that would still be enough to carry TF2 without dealing with much lag with 22ms latency. Perhaps a heat issue, anyhow! Whenever I had the 4x1gb's back in the day, I'd get a series of problems all pretty critical and no one could ever seem to know what they were. One of the hardest/biggest problems was about 95% of my applications "APP CRASHED". Just adding in my 2 cents of misery.