RAM upgrade and frequency for HP EliteDesk 705 G3

[Ravernwest]

Hello,

I may have a problem with my HP EliteDesk 705 G3.

When I use two RAM modules in DIMM1 XMM1 and DIMM2 XMM3 they have a RAM frequency of 2400 MHz but when I put them in DIMM1 XMM1 and DIMM1 XMM2 the maximum RAM frequency will drop to 1866 MHz.

I would like to use four identicly RAM modules but on a maximum freuquency of 2400 MHz.

Is there a way to set this?

I use the newest BIOS version on my EliteDesk 705 G3 and all of the RAM modules are the same original modules from hp (HP24D4U7S8MBP-4).

The APU is an AMD A10 PRO-8775 but I will upgraded it to an AMD A12 PRO-9800 in few days.

[NonSequitur777]

@Ravernwest,

Welcome to our HP User Forum!

Identical RAM sticks (same brand/part numbers) -I would power off your HP EliteDesk 705 G3, remove all RAM sticks, blow out the RAM slots with compressed ('canned') air, and install one RAM stick at a time, making sure you 'snap' each of them gently but firmly, and restart your desktop.  See at what RAM speed each RAM stick runs.

Let's start with this step.

Kind Regards,

NonSequitur777

[banhien]

@Ravernwest 

Its specs

           https://support.hp.com/au-en/document/c05265587#AbT4

which clearly says:

note:

Memory modules support data transfer rates up to 2133 MT/s; actual data rate is determined by the system configured processor. See processor specifications for supported memory data rate

That means you can ONLY get up to 2133MHz as indicated

DDR4-2133 (Transfer rates up to 2133 MT/s)

>>>> The APU is an AMD A10 PRO-8775 but I will upgraded it to an AMD A12 PRO-9800 in few day

The AMD A10 PRO-8775 is NOT on the list above; may be after succesfully upgrade  to  AMD A12 PRO-9800 the problem would go away.

Regards.

[Paul_Tikkanen]

Hi, @Ravernwest 

While I don't know for sure, it may be possible that since you put the memory in slots 1 and 2, it is running in the lower performing 'flex' mode and perhaps the speed slows down to 1866 MHz.

The default position for the memory to run in the higher performing DDR mode is to place the memory where it was originally...in slots 1 and 3.

I'm thinking if you install the same capacity memory only in slots 2 and 4, it will also operate in dual channel mode at 2400 Mhz as well.

I don't think you can run the PC with the two memory chips you have in slots 2 and 4 because DIMM 1 (black) needs to be populated in order for the PC to work, so I don't believe you can test my theory out without having two more matching memory modules.

Now, if you do have 4 of the identical memory chips in all 4 slots, then unfortunately, I have no idea why the speed would have gone down to 1866 Mhz.

There is no way to change the memory speed in the BIOS.

See the service manual, chapter 4, pages 24 - 26 for the memory upgrade info.

It touches upon all the different results when adding memory.

Maintenance and Service Guide HP EliteDesk 705 G3 Small Form Factor

I randomly selected the SFF manual and not the MT manual.

It would be the same for either type PC.