T60/p 3GB limitation? Not quite...

[cchsiao]

Again I raise this topic because I found something interesting...

I am a T60p owner for about 2 years, and I am aware of this 3GB limitation stuff. Although it would be impossible to access the extra 1GB if I installed 4GB on it, I still bought 2 2GB modules in order to speed up the system a little bit. A few days ago I bought an x61s and would like to make it my protable machine. Almost everybody in this forum knows that all 61 systems are capable of addressing 8GB RAM, and that's what I wanna have eventually for my x61s (although I won't buy 2x4GB modules in the near future). Therefore, choosing a good x64 OS becomes very important.

Due to VISTA's big stomach on the resources, I didn't really consider VISTA x64. One good substitution is XP x64, but I found that its lack of supports on a lot of traditional thinkpad softwares, such as Access Connection, is really a minus. I don't have Windows server 2003/2008, so the only thing I can try is Windows 7 x64. Yes, it's still a beta product, but we can look forward to its coming next year. Moreover, according to the test result on Tom’s hardware, it looks quite promising that it is much less resources hungry than VISTA. So… I tried to install a copy of Windows 7 x64 on my x61s and see if it fits my need.

Wait… I don’t have an x6 dock. So what I do is installing Windows 7 x64 on my T60p, and then put the hard drive back to x61s. After finishing installing Windows 7 x64 on T60p, something magic happened as I checked system in the control panel! It shows 4GB RAM installed on my T60p! I didn’t tried installing a VISTA x64 on my T60p, so I don’t know what I will see in VISTA. However, I do see 4GB RAM in Windows 7 x64. If this means that I can access full 4GB RAM in my T60p, I’d definitely switch to Windows 7 right after it launches.

Any ideas?

[tdawg5480]

It will show 4 gb of ram in the OS but the machine will not address it and utilize it.

Also the 3gb limit is a hardware limitation of these intel 945 chipset

[Marin85]

The 4GB would also show up under Vista after SP1. Vista (resp. Windows 7) simply reports what is installed in your system, not what is usable. The 3GB limitation is a hardware one, so even in infinite future there won´t be any OS that will be able to address all 4GBs in a T60(p) machine.

Cheers

Marin

[beGi]

You can see how much RAM is available to your system in Task Manager (or it's equivalent in Windows7)...

[crazyfrog]

I can confirm it is nothing more than microsoft's trick. I am running Vista SP1 64-bit on my T60 with 4GB (2GBx2) memory. Windows Welcome Center reports '4.00 GB RAM', but Windows Task Manager shows a total of 3069MB physical memory.

The only benefit of installing 4GB in a T60/p is slight improvement in performance due to symmetric dual-channel memory. Humm... maybe.

[Marin85]

slight improvement in performance due to symmetric dual-channel memory. Humm... maybe.

...about 8% difference compared to asymmetric dual-channel when performing memory-intensive tasks.