[deivid725]

I am about to upgrade my ram from 2gb to 4gb. I heard that if you have 4gb or more that you should have a 64bit windows disc. But i only have the 32bit windows vista disc. I was wondering if i add the 2gb and i still have a 32bit system installed, will there be an error of any kind?

[Advertisements]

No, no error. The system will use about 3.2GB of the 4GB, the rest will be used for hardware. Read here: The 3GB-not-4GB RAM problem

[Ztruker]

No, no error. The system will use about 3.2GB of the 4GB, the rest will be used for hardware. Read here: The 3GB-not-4GB RAM problem

[deivid725]

Thanks for the fast reply.

Umm what do you mean by the rest of the ram will be used for hardware?

[Ztruker]

From the link I gave you:

This behavior is due to "memory mapped IO reservations". Those reservations overlay the physical address space and mask out those physical addresses so that they cannot be used for working memory. This is independent of the OS running on the machine.

Significant chunks of address space below 4GB (the highest address accessible via 32-bit) get reserved for use by system hardware:

• BIOS – including ACPI and legacy video support

• PCI bus including bridges etc.

• PCI Express support will reserve at least 256MB, up to 768MB depending on graphics card installed memory

What this means is a typical system may see between ~256MB and 1GB of address space below 4GB reserved for hardware use that the OS cannot access. Intel chipset specs are pretty good at explaining what address ranges gets reserved by default and in some cases call out that 1.5GB is always reserved and thus inaccessible to Windows.

[Digerati]

If you are still considering upgrading to 64-bit Windows 7, understand all your hardware devices will require 64-bit drivers. So before upgrading, visit the download pages for your all your hardware to make sure 64-bit Windows 7 drivers are available. If your hardware is fairly new, it should not be a problem.

Note besides being able to use the full 4Gb, 64-bit Windows 7 has a few security enhancements over the 32-bit version - always a good thing.

[deivid725]

Thank you digerati and Ztrucker i think i will upgrade to a 64 bit so i can use all of my memory.

[Digerati]

Well, understand the performance difference between 3.2Gb and 4Gb will be minimal at best - other than by the placebo effect. If you really want to take advantage of 64-bit, bump it up to 8Gb (6Gb with triple channel motherboards).