Possible.

[thinkpadcollection]

There are different i7 processors on same G2 socket that takes 16GB or 32GB max
For example:

dual core i7-2620M is 16GB dual channel; 1066/1333 fsb. 35W
quad core i7-2820QM is 32GB dual channel; 1066/1333/1600 fsb. 45W
note: these wattage is TDP, dual channel means two slot memory usually and all are DDR3 type.

Cheers, thinkpadcollection

[brchan]

Correct, only the quad core I7 processors can take 32GB ram, dual cores cannot. This is why you see 'dummy' slots in non QC W520 models, for example. There will be 4 slots, but 2 of the slots under the keyboard will have 'dummy' sticks in them. Putting ram here will not allow the computer to boot.

[ajkula66]

While some of these CPUs themselves are capable of addressing 32GB of RAM, they are only able to do so in the 4-slot environment of the W520.

There are no DIMMs larger than 8GB that will work in these machines.