Question Can a bad motherboard cause issues with reaching full RAM speed?

[mildw4ve]

Can a potentially bad motherboard post no problem but cause issues with reaching full RAM speed?

I have an Asus A320I-K MOBO, newest BIOS, enabled DOCP
CPU is Ryzen 3600 and 5600X (tried both)
This setup should support 3200MHz RAM but the best I got from testing 5 different 3000-3200MHz RAM sets was 2666MHz, most is stuck at 2133MHz (3/5).
When I enable DOCP or try to start small and set frequency to 2400 (from 2133) after I reboot it throws a red LED and goes back to 2133MHz

I'm running out of ideas, can it be the motherboard?

 

[drea.drechsler]

Have you reset CMOS every time you change either the memory kit or processor?

One thing I've found when it won't run at rated XMP (DOCP) speed right off is to manually set the DIMM voltage first. You might also set it fairly high....maybe around 1.4V. If it boots, you can lower voltage to find the sweet spot.

Don't be afraid of voltage, DDR4 is tested and certified to run at 1.5V. But some DRAM's, like Hynix CJR, don't like when voltage is too high and become less stable.

 

[mildw4ve]

Have you reset CMOS every time you change either the memory kit or processor?

One thing I've found when won't run at it's rated XMP (DOCP) speed right off is to manually set the DIMM voltage first. You can also set it fairly high....maybe around 1.35-1.4V. If it boots, you can lower voltage to find the sweet spot.

Not every time but I did do a few resets. Twice I had to jump CLRTC pins because it would not post after BIOS settings changes. I also tried loading default settings from BIOS a bunch of times, I think that's the same thing (?)
I did try manually setting the voltage to 1.35-1.40 but it didn't help. Enabling DOCP also sets DIMM voltage to 1.35V with I think all of the sets I tried.

 

[drea.drechsler]

Not every time but I did do a few resets. Twice I had to jump CLRTC pins because it would not post after BIOS settings changes. I also tried loading default settings from BIOS a bunch of times, I think that's the same thing (?)
I did try manually setting the voltage to 1.35-1.40 but it didn't help. Enabling DOCP also sets DIMM voltage to 1.35V with I think all of the sets I tried.

Resetting it by taking out the battery can also help. Leave it out for several minutes, shorting the CLRTC pins at the same time.

Yes, DOCP should set the DIMM voltage. I'm not sure why but it's not uncommon for it to not "take" on initial restart after setting it. It hurts nothing to set it manually, so that's what I do.

The idea behind clearing CMOS is to force the CPU to retrain memory, a good idea after changing memory or CPU. I'm not sure setting optimized defaults will do that, but resetting cmos with a battery pull is certain to do it.

 

[mildw4ve]

Resetting it by taking out the battery can also help. Leave it out for several minutes, shorting the CLRTC pins at the same time.

Yes, DOCP should set the DIMM voltage. I'm not sure why but it's not uncommon for it to not "take" on initial restart after setting it. It hurts nothing to set it manually, so that's what I do.

The idea behind clearing CMOS is to force the CPU to retrain memory, a good idea after changing memory or CPU. I'm not sure setting optimized defaults will do that, but resetting cmos with a battery pull is certain to do it.

Thanks, I just tried it and unfortunately no change. But I did notice something interesting. I tried it with the single stick from the set that is able to reach 2666MHz (GSkill). After full reset with CLRTC and battery unplugged it still set to 2666MHz but when I try to change it to 2400 or 2133 it doesn't do anything. So it not only can't go higher but also can't go lower.
It's as if anything I try to get in BIOS the motherboard just ignores. Whats going on here?