Adding RAM for HP Elitebook 840

[Dallas_LT]

Serial: Edited
Product: X3V02AV
Two RAM slots, one filled originally with 4GB Samsung RAM.
I want to upgrade RAM  to 2x16GB or 2x8GB.
I bought 2x16 AFOX SO-DIMM DDR4 16GB 2400MHZ but returned because they were not compatible even after BIOS upgrade.  JEDEC profile seemed to be ok.

How do I know which RAM should i safely buy, while not overpaying?
The models seems to be rather picky..

Thanks a lot.

[Paul_Tikkanen · Accepted solution]

Chapter 1 of the service manual indicates 32 GB of memory is supported.

If you want to install 2 x 16 GB of memory, see if you can get this chip in your country:

Timetec 16GB DDR4 2400MHz PC4-19200 Non-ECC Unbuffered 1.2V CL17 2Rx8 Dual Rank 260 Pin SODIMM Lapto...

16 GB chips have to be 2Rx8 and for a DDR4-2400 chip the CL must be 17.

An 8 GB chip can be 1Rx8.

[Dallas_LT]

Thanks a lot! 

[Paul_Tikkanen]

You're very welcome.