Can anyone explain this? (Vista recognizing RAM.)

[9007938]

When I installed Vista via BootCamp 2.0 it only recognized 2.98GB of RAM. I was told I had to upgrade to Vista x64 to have it recognize all 4GB in my iMac. However, a bit ago my computer asked me to update to Boot Camp 2.1, which I did. It then let me download a few Windows updates that weren't available previously (Service Pack 1 and a few other random things).

After installing the updates my RAM now shows as 4.0GB. I'm thrilled but I want to make sure this isn't a fluke and just wanted to see what you guys thought and how this could have happened?

 

[steveza]

This is a feature of SP1. Not all of it will be accessible by the OS but it reports all the installed memory up to 4GB on 32bit versions.

 

[9007938]

This is a feature of SP1. Not all of it will be accessible by the OS but it reports all the installed memory up to 4GB on 32bit versions.

How can I tell how much of it is accessible?

 

[shmutheprophet]

How can I tell how much of it is accessible?

The same amount is accessible. You can still only use 2.98GB. SP1 just now correctly shows how much is installed. To use all 4GB - you do need to have Vista x64.

 

[goinskiing]

I see it as a cover-up from Microsoft.

From what I can tell, ALL it does is reports what you have installed, not necessarily what is being utilized. Someone can correct me if I'm wrong though.

Gotta love M$.

 

[alphaod]

From what I can tell, ALL it does is reports what you have installed, not necessarily what is being utilized.

What's wrong with that; better then it shows not what you installed and pretends you only have less.

You can see how much it's using in Task Manager.

 

[Daveoc64]

I see it as a cover-up from Microsoft.

From what I can tell, ALL it does is reports what you have installed, not necessarily what is being utilized. Someone can correct me if I'm wrong though.

Gotta love M$.

Really, it makes sense. A lot of people get so confused by 4GB of RAM in a computer.

 

[steveza]

Indeed - they probably received many support calls as people were upgrading their RAM and not seeing half of it. For some people (I guess the majority of users) that do not understand the difference between a 32bit and 64bit OS it was probably easier to just show the total installed RAM.

 

[Infrared]

When I installed Vista via BootCamp 2.0 it only recognized 2.98GB of RAM. I was told I had to upgrade to Vista x64 to have it recognize all 4GB in my iMac. However, a bit ago my computer asked me to update to Boot Camp 2.1, which I did. It then let me download a few Windows updates that weren't available previously (Service Pack 1 and a few other random things).

After installing the updates my RAM now shows as 4.0GB. I'm thrilled but I want to make sure this isn't a fluke and just wanted to see what you guys thought and how this could have happened?

http://support.microsoft.com/kb/946003

 

[eXan]

I've installed 4 GBs in iMac and XP Pro SP2 only recognizes 2.98 GB

I thought you need 64 bit only if you want to go beyond 4 GB, no?

 

[Stridder44]

I see it as a cover-up from Microsoft.

From what I can tell, ALL it does is reports what you have installed, not necessarily what is being utilized. Someone can correct me if I'm wrong though.

Gotta love M$.

A cover up from Microsoft (or as you uniquely put it, "M$")? Yes, it's all Microsoft's fault. They love tricking you. They just stay up all night and scheme of ways to trick you. Or, there is no conspiracy and it's actually just a hardware memory addressing issue on 32-bit OS's, one the would be true for Microsoft, Apple, Linux, or ANY OS. But, no, it's all "M$" fault.

It doesn't matter how much it says you have. You could probably "hack" it to say whatever number you want, but it wouldn't matter. A 32-bit OS can only use no more than 4 GB of RAM (but usually you'll only have 3 - 3.5 available). On a 64-bit OS, that goes away, and instead becomes some absurdly large number, allowing you to use just about however much you can stuff in there (although I think Microsoft puts a limiter on Vista of 128 GB of RAM, but in actuality a 64-bit OS could see more than that).

 

[steveza]

I've installed 4 GBs in iMac and XP Pro SP2 only recognizes 2.98 GB

I thought you need 64 bit only if you want to go beyond 4 GB, no?

Indeed - you need a 64bit OS to use more that 4GB RAM - 32bit Windows normally uses up to 3.5GB max.

 

[9007938]

A 32-bit OS can only use no more than 4 GB of RAM (but usually you'll only have 3 - 3.5 available).

This doesn't make sense. Why do people keep saying a 32-bit OS can use 4GB of RAM yet it only reports ever being able to use 3GB? What is happening to the other 1GB? This doesn't make any sense AT ALL.

 

[Stridder44]

This doesn't make sense. Why do people keep saying a 32-bit OS can use 4GB of RAM yet it only reports ever being able to use 3GB? What is happening to the other 1GB? This doesn't make any sense AT ALL.

Like I said, because of memory addressing issues. 32-bit OS can only address up to 4 GB, 500MB - 1GB of which is used for physical memory addressing space (hardware), and the rest for actual memory (3.5GB - 3GB). If you want to really understand why in technical terms, read here.

To address 4GB of memory you need 32 bits of address bus. (Assuming individual bytes are addressable.) This gives us a problem - the same problem that IBM faced when designing the original PC. You tend to want to have more than just memory in a computer - you need things like graphics cards and hard disks to be accessible to the computer in order for it to be able to use them. So just as the original PC had to carve up the 8086's 1MB addressing range into memory (640K) and 'other' (384K), the same problem exists today if you want to fit memory and devices into a 32-bit address range: not all of the available 4GB of address space can be given over to memory.

Before XP, Vista, and Mac OS X came along (which are all 32-bit OS's), we had 16-bit OS's. 32-bit OS's have been common for a long time (like the past 10 + years), and now that people are using more than 4 GB of RAM, 64-bit OS's are taking over (Leopard, Vista, Linux, etc.). So again, this has nothing to do with just Microsoft. The rule is true for ANY OS.