Thinkpads Forum

Hello,

I have a T400 type 2007. When I got it I originally upgraded it to 8 GB of PNY RAM. I had been reading that it is possible to get it to 16 GB so I got 16 GB of PNY (2x8GB). It didn't like that at all, I got the 1-3-3-1. Thinking the RAM was bad, I sent it back and got Crucial, same thing happened. Just to be certain, I put the 16 GB in an X120e just to see what happened, and it worked and was recognised. Needless to say I am a bit confiused since the RAM seems to work, but just not in the T400, but the older 8 GB (2x4GB) still works when I put it back in. I am a bit confused and wonder if anyone else has had this issue and if so, how did they solve it? I am happy to add other details should anyone need them.

The T400 can support a maximum DIMM size of up to 4GB per slot, for a maximum of up to 8GB.

AFAIK the T400 only supports 2x4=8GB, even though the chipset and the CPU could theoretically support up to 16GB.
Don't know where this limit is set in this machine.
And you also have to be careful WHAT brand RAM you put in, as not all brands are equal!