I'm well aware...I did all the memory testing on the 2020 for Rob (RIP) at BareFeats...
real world speed test results for performance minded Macintosh users
barefeats.com
according to your link, your conclusion is, (and you write)
"If you don't fill all memory slots, putting memory modules in slots 1 and 3 (or 2 and 4) insures Dual Channel memory mode."
BUT is that grouping, of the memory, over the same "Channel" ?
when I look at my iMac's (in signature below) system report, it details the following, for the total of 40GB's of installed memory.
I am keeping the same Matching memory, within the same "Channel".
Is this not correct? or do I move the memory so a 4GB module and a 16GB module reside in the same "Channel" AND in slots 1 & 3, AND 2 & 4?, as your referenced article implies?
Memory Slots:
ECC: Disabled
Upgradeable Memory: Yes
Slot 1 (Channel A / DIMM 1):
Size: 4 GB
Type: DDR4
Speed: 2667 MHz
Status: OK
Manufacturer: Micron
Part Number: 4ATF51264HZ-2G6E3
Serial Number: 290A1B0D
Slot 2 (Channel A / DIMM 0):
Size: 4 GB
Type: DDR4
Speed: 2667 MHz
Status: OK
Manufacturer: Micron
Part Number: 4ATF51264HZ-2G6E3
Serial Number: 290A17C2
Slot 3 (Channel B / DIMM 1):
Size: 16 GB
Type: DDR4
Speed: 2667 MHz
Status: OK
Manufacturer: 0
Part Number: -
Serial Number: 80AF0154
Slot 4 (Channel B / DIMM 0):
Size: 16 GB
Type: DDR4
Speed: 2667 MHz
Status: OK
Manufacturer: 0
Part Number: -
Serial Number: 80AF02EC