Question I need help with ram dimms

[Vsainz]

I have an HP 705 g1 sff with an AMD A-10 7800b APU, and it was working in dual channel mode in DIMM slots 1&3 and the ram sticks that I was using are :
Ramaxel 4gb 1333mhz
Hynix 4gb 1333mhz

2 days ago I bought one extra 4 GB RAM stick that was a Samsung one and was 1600mhz (800mhz if working alone) to upgrade the PC and installed it in DIMM slot 4
It was installed successfully and detected in bios but in windows
My hardware reserved RAM was 9 GB, and my IGPU uses 1GB of them regularly which means 2 sticks are not usable so one stick / 2.9 GB is usable but when I removed the new stick and booted Windows showed 5 GB of hardware reserved RAM

I tried several things:

-reseating the CPU and ram

-Disabling maximum boot RAM in Windows

-loosening the CPU cooler and mobo screws

-Unplugging the mobo power cable and plugging it again

finally, I tried switching the RAM places and what I found was:

-1 stick only in slot 1: boot and fully usable

-1 stick only in slot2 or 3 or 4: PC doesn't even post and the CPU fan goes racing mode

-2 sticks one in slot1 and the other in slot 3 or 4: one is usable and the other is detected in bios and windows but is hardware reserved

-2sticks one in slot1 and the other in slot 2: both work and are fully usable and the hardware reserved RAM is 1 GB but in single channel mode

-2sticks In slots 3&4: pc doesn't post and the CPU fan goes racing mode again

-Lastly when I put one in slot 2 and the other in slot 3 or 4: the PC doesn't post and the CPU fan goes racing mode AGAIN

I don't what can I do to fix this problem but the most sus thing is that the PC works perfectly if the RAM is in slot 1&2 but when the RAM is in slots 2& 3 or 4 BOTH RAM sticks are not detected or bootable

I am sorry for my bad English and very thankful for any responses

 

[Lutfij]

Welcome to the forums, newcomer!

You might want to stop mixing and matching rams in a build. To add, if you're able to POST with the original stick of ram that the prebuilt came with, check and see if your HP prebuilt has any BIOS updates pending. I'd then advise to invest in a ram kit. One that's rated to run at least DDR3-1600MHz and has tight latencies.

Your APU and platform should be able to work with DDR3-1866MHz but only if the airflow in your prebuilt is great, which I doubt.

 

[Vsainz]

Welcome to the forums, newcomer!

You might want to stop mixing and matching rams in a build. To add, if you're able to POST with the original stick of ram that the prebuilt came with, check and see if your HP prebuilt has any BIOS updates pending. I'd then advise to invest in a ram kit. One that's rated to run at least DDR3-1600MHz and has tight latencies.

Your APU and platform should be able to work with DDR3-1866MHz but only if the airflow in your prebuilt is great, which I doubt.

thank you for the quick response

First, the Ramaxel and Hynix were the original RAM that came with the pre-built cause it was a used one I bought from a local seller which was a bad idea ngl 🙁

Second, the airflow is good in my case because I removed the side panel which let more dust un the PC but I clean it every 2 weeks

I have the latest bios ver
and there are no bios updates in my HP

 

[Misgar]

I don't suppose by any chance you're using a 32-bit Operating System instead of 64-bit are you? 32-bit OS are limited to roughly 3.5GB RAM, regardless of how many GB you fit over 4GB.

I'd be inclined to test each DIMM on its own with Memtest86+, booted from a USB memory stick. Mixing dissimilar DIMMs could be confusing the BIOS with multiple SPD readings to choose between.

https://www.partitionwizard.com/clone-disk/hardware-reserved-memory-windows-10.html

 

[Vsainz]

I don't suppose by any chance you're using a 32-bit Operating System instead of 64-bit are you? 32-bit OS are limited to roughly 3.5GB RAM, regardless of how many GB you fit over 4GB.

I'd be inclined to test each DIMM on its own with Memtest86+, booted from a USB memory stick. Mixing dissimilar DIMMs could be confusing the BIOS with multiple SPD readings to choose between.

https://www.partitionwizard.com/clone-disk/hardware-reserved-memory-windows-10.html

i use a 64-bit win 10 system and did try memtest86 and got 0 errors