Confusing RAM readings

Seb86 · March 5, 2022

Hi everyone, i was checking some ram readings since i was suspecting XMP wasnt doing his thing, i build my rig in 2017 with this asus prime z270f gaming, i7 7700k and 2 8gb sticks of ddr4 2400 corsair vengance ram so i got 16gb total, in 2019 i bought another kit same size but the top speed was rated at 3000 mhz, i set all memory timings and speed with XMP to match the 2400 mhz modules that where runing in dual channel (slot A1 B1 for the older modules and A2 B2 for the new ones) you can see in the attachments the first 2 captures are from the first kit installed in slot 1 and 3, the second in 2 and 4, and the second kit says single channel.... is that a bug? what´s the deal? did i mess up? i´ve been working and building computers since 2005 until 2014 so i now some technical stuff, can someone enlighten me on this issue if there is any? i updated the BIOS to the newer non beta one, it was 0801, the newer one said it was for windows 11 support and said "beta state" at the asus site, BIOS shows target memory speed at 2400 and each module at that speed in the monitor tab, but when i switch to each individual slot stats shows the second kit with 2 speeds 2133 and 3000 only while the old kit shows 2133 and 2400

Levent · March 5, 2022

5 minutes ago, Seb86 said:

and the second kit says single channel.... is that a bug?

No it doesnt. It says Single RANK. It is a completely different thing. Your ram is running at dual channel mode with 2 dual rank dimms and 2 single rank dimms.

Eigenvektor · March 5, 2022

The "Memory" tab shows your RAMs current speed and timings. It is running in dual channel and 1200 MHz (=2400 MT/s), so the RAM is running at the expected speed (in marketing terms 2400 MT/s = 2400 MHz "effective" clock speed, due to DDR = double data rate)

The SPD tab shows you possible speeds the RAM sticks support (e.g. which JEDEC and XMP profiles they have), not what is currently going on. And as @Levent said, dual rank is not the same as dual channel. Dual rank means there's there's two ranks on a single stick (which can improve its latency), while dual channel means two channels can be accessed at the same time, which improves bandwidth.