Hands on: Embrace the spirit of 64-bit

Four pairs of 2GB memory cards at the time of writing were prohibitively expensive, so we fitted an additional pair of 1GB Crucial DDR-II cards to increase the system memory to 4GB.

Upon rebooting the system, the Bios reported 4GB of Ram, but 32-bit Windows Vista Ultimate only ‘saw’ 3,199MB of the total system memory.

The motherboard Bios confirmed this, with its system page reporting that while the total memory measured 4,096MB, 896MB had been ‘appropriated’ by devices, leaving 3,200MB for the system.

Zero appropriation
We then entered the Bios Chipset configuration page and enabled the Memory Remap Feature, although we noted a warning this was only suitable for 64-bit OSs. The Bios System page now reported 0MB had been appropriated and 4,096MB was available.

We didn’t expect 32-bit Vista to see all of it, but were surprised to find that with the Memory Remap Feature enabled, the system Ram was now being reported as a lower figure of 3071MB. So if you’re running a 32-bit OS, you may wish to experiment with this setting, along with the PAE switches mentioned earlier.

The addressing limitations of 32-bit operating systems will always involve some compromise when it comes to this amount of Ram though, and the only real solution is to switch to a 64-bit OS.

So we reinstalled Vista Ultimate using the 64-bit version, and with Memory Remapping enabled in the Bios, the operating system reported 4095MB of Ram without any issues.

Alternative fit
If you’re using a 32-bit OS, you’ll never be able to use all of the Ram in a 4GB system. You should be able to use around 3GB, so it’s up to you if you’re happy losing one quarter of it.

An alternative is to fit 3GB of physical Ram, although check your motherboard for compatibility and go for a pair of 1GB and a pair of 512MB modules for dual-channel support.

Ultimately, you’ll need a 64-bit OS to exploit 4GB or more of memory, but even then your applications may not see the benefit. In future columns we’ll examine the performance benefits of 4GB or more.