Are 16GB RAM (2x8Gb) possible on my Lenovo T400?

"Here's what the Lenovo support doc states: Detailed specifications - ThinkPad R400, T400.

From what I can find this system is limited to 8 GB total RAM (2 x 4 GB modules). I don't see any references on anyone trying to push this system beyond that.

Remember your OS is also a factor here, you'll need a copy of a 64bit version of Windows before even trying more than 3 GB.

As long as you can return the memory you could give it a try. If you do, first try one 8 GB module first then try two. Please let us know what you discover."

"I was able to upgrade my laptop to 16 GB.

2 pitfalls:

1. Corsair RAM does not play well despite Corsair's claims. Stick to either an OEM supplier or Crucial.

2. Both sticks of RAM must be the same size. Otherwise, you may see strange things on your screen. This is a known bug with the Intel chipset in this laptop."

I own a Lenovo T420 and have been running 16Gb (2x8Gb)for years now. When I initially did this 3 years ago, I did make sure I was using the latest BIOS at the time, and after putting the 2 8Gb Crucial SoDIMMS in it was recognized by the BIOS at first boot. After saving the bios, F10, I rebooted into W7 x64 Professional with no issues as well...with it recognizing all 16Gb of it. I upgraded to Windows 10 x64 Pro since then and again no issues. On both W7 and W10, I disabled Virtual Memory altogether by opting for "No Page file" and have had no issues in doing that either. Hope this helps someone.