If you mix RAM modules with different clock speed specifications the memory controller will always read the SPD information of each channel, and configure the memory bus to run at the speed of the slowest module. In that sense, dual channel memory would work out to be slower than using one stick.
However when you buy new RAM, if you choose a module that match the timings of your existing installed RAM (the onboard soldered RAM), then there should be no performance hit, because the memory controller can configure the memory bus at the same speed as both RAM modules.
If the soldered ram died, would adding a stick in the second slot work? Interesting question
. I have not seen this problem so I am making an educated guess based on my understanding of PC RAM. There could be more than one answer depending on if i) the soldered RAM was undetected by UEFI at POST, or whether ii) the soldered RAM was detected by UEFI at POST but exhibited faulty memory cells when the OS launches and tries to use them.ii) If the RAM in question is detected by UEFI and has faulty memory cells, then the computer would BSOD, as this faulty RAM would always be configured for use - you would need replace the motherboard to repair.
It may be possible to put jumpers on the motherboard, to enable/disable the RAM channels. Then you would have a robust way of selecting which channels you want to power up into the computer configuration. But I have not heard of any manufacturer doing that on their mobos.
i) If the RAM in question is undetected by the memory controller, then there is a chance it will just detect the SPD of the SODIMM RAM, and configure that RAM for use by the computer. So, you could get away with it for years and years.
On the other hand, some memory controllers like to detect RAM in channel 1, before attempting to detect the RAM in channel 2. My current motherboard is like that, so I have reservations that other motherboards would do the same. It is not guaranteed to work.
Terminology
RAM - Random access memory
SPD - Serial presence detect
UEFI - Unified Extensible Firmware Interface
POST - Power-on self-test
OS - Operating system
BSOD - Blue (or Black) Screen of Death
SODIMM - Small outline dual in-line memory module
My Computers
System One System Two
-
- OS
- Windows 11
- Computer type
- PC/Desktop
- CPU
- AMD Ryzen 5 5600
- Motherboard
- MSI B550-A Pro
- Memory
- 16 GB
- Graphics Card(s)
- Sapphire Radeon RX 6500XT (8 GB version)
- Monitor(s) Displays
- BenQ Mobuiz EX2710Q QHD, Iiyama ProLite X23377HDS
- Hard Drives
- MSI Spatium M461 4TB
-
- Operating System
- Windows 11
- Computer type
- Laptop
- Manufacturer/Model
- Acer A114
- CPU
- Intel Celeron N4020
. You used to be able to fix them yourself - now it needs specialist repair.
I didn't read this until after I posted the above. Yes, it's a business-class machine every time for me.
