Thinkpads Forum

I'm finding out that even though you can install 4GB in a T60, Windows XP is limited to seeing 3GB. Also hearing that Vista will then allow the full use of 4GB if installed.

Can anyone confirm?

Thanks

For use of 4GB you need 64-bit OS (XP-64, 2k3-64, Vista-64 or Linux). Don't know if 32-bit Vista will be able to handle more than 3GB. 64-bit Vista and XP will certainly handle more.

For 64-bit OS you need a 64-bit CPU, currently there are no Thinkpads yet with 64-bit CPUs (Core 2). End of this month or in November the line will be updated to Core 2 CPUs.

Unless you're doing something extreme 2GB of RAM should be enough for a year or two, at which point it will be time to upgrade to 64-bit CPU and OS.

Don't know if you'll be able to just replace CPU with Core2 Duo or you will need a new motherboard.

Problem is there are no more UXGA Flex LCDs, so Merom (Core2D) Thinkpads will come without one, which is really a shame. UXGA 64-bit dual laptop would really have been the ultimate machine.

Actually, not quite.

This has been gone over before, but it deserves going over again.

The CPU has PAE, Physical Address Extension, which let's it address far upwards of just 2GB of memory. 2GB is mainly, now, a Windows XP limitation. Windows XP is built off of Windows 2000 and Windows 2000 can also, only, handle 2GB or 3GB with the optional boot flag. Windows 2003, on the other hand, can handle far more memory as opposed to either XP or 2000. It isn't just being 64-bit or not, although that makes things simpler from the beginning in terms of designing the OS memory handler. Hence, it is primarily a limitation of Windows XP, going to roughly 3.24GB at max, and Windows 2003, going to around 4GB per user max, and not just a 32-bit scheme. A 32-bit Intel chip without PAE would certainly not be able to do that, but those aren't the recent Pentiums and, now, the Core Duos.

See http://forum.thinkpads.com/viewtopic.php?t=28078