And there are various models. I'd find the service manual on hp and see if you can figure out exactly which one you have.
The only folk I know going past 16GB are well, I won't write what I'm thinking here but it's kind of silly past 16GB today.
http://h10032.www1.hp.com/ctg/Manual/c03905828 seems to write it does indeed vary.
Starts at page 2.
I have a refurbished Hp Elitebook 8570 W. Settings about describes Intel I7 with current memory of 16 GB. Bios reflects the same with a 3720 QM processor. Crucial scanner reports the same as well as 32 GB capacity, 2 Banks ,2slots each. I have both slots behind the lower cover filled, 8GB each. I had removed the keyboard which HP says is the location for the 2nd Bank. Nothing there ; meaning no slots. I this a QM, or an M. If so why are all the Info replies with the latter????

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