What Is Maximum Memory Support For 32 Bit Vista?

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Hi All

what is maximum memory support for 32 bit vista?

My notebook is Lenovo T400 with 32 bit Vista business, I've checked from Microsoft website that max support 4G RAM, but lenovo website Note: Only 64-bit operating systems support more than 3GB of system memory (RAM).

which I should believe?

4 or 3?

Thanks

[Tywais]

which I should believe?

4 or 3?

3 Gigabytes recognizable by the operating system due to the system BIOS IO mapping to memory space. Some mainboards can potentially re-map IO to high memory using PAE (Physical Address Extensions) and the full 4 can be seen by the OS but most can not. So you can put in 4 Gigabytes but the OS will only be able to use around 3GB plus.

[dave_boo]

To expand upon what Tywais stated (or dumb it down 'cuz his response was highly technical), your motherboard reserves a portion of memory for accessing input/output. This depends upon a number of variables such as your videocard's memory, bios memory, IRQ, etc. Back in the OMG I have 64mb of RAM it was thought that they'd be safe to map this reserved up to 4,0 GB and below (which is the max that a 32 bit processor can access). Well 32 bit has hung around too long. That 4,0 GB that would have cost you a house back when decisions were being made is now some 15 000THB. And if people can afford it they'll get it.

Funny thing is though, in regards to the PAE quote, you need a 36 bit processor. AFAIK, since the Pentium Pro every single processor has actually been 36 bit. Since 2bits^32=4 GB, and 2^36=68 GB you can see why they went that way.

However, if you have a 64 bit processor, use it (**edit** with a 64 bit OS **edit**)! The 64 bit extensions will give you access to a maximum of ~17 BILLION GB. Good luck buying that much RAM. But than again, you'd still lose that last ~0.8GB.....

Edited May 11, 2009 by dave_boo

[Phil Conners]

That 4,0 GB that would have cost you a house back when decisions were being made is now some 15 000THB.

You mean 1,500 baht, right? 750 baht per 2GB stick last I bought...

[H2oDunc]

Can also confirm that 32 Vista will only see 3gb. The price is also falling. Here on Samui they were asking for 1400 baht for 1gb yet in BKK got a 2gb stick for 1000 baht. it certainly has speeded up my system though, well happy

[dave_boo]

That 4,0 GB that would have cost you a house back when decisions were being made is now some 15 000THB.

You mean 1,500 baht, right? 750 baht per 2GB stick last I bought...

Yeah, got carried away with my zeroes (does that word have an e in it?). Still off in Farangland so was translating the prices to THB; my mind ain't what it used to be.