RAM upgrade to 40GB 16+8+8+8 crashes on the last 8 in DIMM 1

[Dickie-07]

I purchase a refurbished G4 decided to upgrade the RAM I installed 16 Gb in slot 4 8gb in slots 3,2 and when I tried to install the last 8gb in slot 1 the system would not boot to windows?

[NonSequitur777]

@Dickie-07,

Welcome to our peer-to-peer HP Community Forum!

Your HP EliteDesk 800 G4 Small Form Factor PC is capable to be fitted with up to 64GB of DDR4 PC4-21300, 2666 MHz, Non-ECC, Unbuffered, DIMM (UDIMM), 288-pin RAM, but HP computers are known to be finnicky when it comes to mixing RAM (different brands, models, speeds, and capacity).

My suggestion is to 'stick' with either all 8GB RAM sticks, or 16GB RAM sticks.

Kind Regards,

NonSequitur777

[Dickie-07 · Accepted solution]

I put 16Gb Dimm 1 slot which is Channel B where the 8gb was when I got the computer so I tried with 16gb in slot 4 Channel but didn't work again  so I changed around the order with 8GB in slot 4 channel A 16gb slot 3 Channel A  the remainder in slot 2,1 and it finally accepted that order now have 40GB RAM

[NonSequitur777]

@Dickie-07,

Outstanding!  -Happy you got it to work.

[EDIT:] The only thing you could consider to check is how well your 40GB with mixed RAM performs.  You could run the freeware UserBenchMark performance software and see what it scores: UserBenchmark: HP EliteDesk 800 G4 SFF Compatible Components.  For example, before I swapped/upgraded my HP EliteDesk 800 G4 SFF for an EliteDesk 800 G5 SFF motherboard, this was my RAM score:

Link: HP EliteDesk 800 G4 SFF Performance Results - UserBenchmark.

Kind Regards,

NonSequitur777