T400 Max installable memory?

[vtphillips]

I'm looking to buy a used T400.  I see some T400 max out at 4GB RAM, and some max out at 8GB but, I haven't been able to find any way to tell, which systems max at what amount?  I want a T400 that supports 8GB of RAM.  How can I tell, before I buy the used system, how much maximum memory it supports? -Thanks.

[erik Community SuperMod]

welcome to the forum!

all T400 models support 8GB.   they use the same chipset in each one with the only difference being the processor.

[andyP Community SuperMod]

vtphillips, welcome to the forum,

all T400s will max out at 8GB RAM, because at the moment 4GB sticks are the biggest you can buy, the OS makes the difference, (assuming a Windows OS); x86 OS only up to 3.25GB, X64 is dependent on the OS. See here.

Hope this helps 

[vtphillips]

Thanks Eric and Andy.  The Lenovo support site says a max of 4GB so, it's very confusing.  Do you guys know, will it support even larger DIMMs, as they are released?  8GB, etc ...?

[erik Community SuperMod]

if 8GB DDR3-1066 SODIMMs are released, they should be supported.   until they are released (if ever) and someone tests them, the certainty of this is unknown.

4GB modules are still quite expensive.   those needing 16GB will likely move to something like the W510 where it has four memory sockets and allows a much more affordable way to upgrade.

you'll likely upgrade your system long before installing two 8GB modules will be affordable.

[roybishop]

Lenovo's web site hasn't been updated for all models.   Crucial will sell you 8 GB for any T400:

http://www.crucial.com/store/listparts.aspx?model=ThinkPad%20T400%20Series