[SOLVED] 2 ram modules works, 4 do not works

[Superfrog79]

Hello guys,

I am new to this forum. I read a lot of good stuff here and I did manage to solve lot of my problems. But, now I have silly problem I could not solve. I wanted to make my first PC Battle-station. I bought ASUS Z390-E gaming mobo and Kingston Predator 3200 MHz RBG 2x16Gb kit HX432C16PB3AK2/32.

Before buying I checked manual for memory compatibility. At first, I tried to install memories in suggested memory slots, like I found in pdf manual in slots B2 and A2 and that did not worked. Then I put 2x16GB in slots A1 and A2 and that worked fine. After that I installed windows 10 pro with uefi bios and everything is working fine.

Month after that I bought one more kit to upgrade my machine to 64 Gb of total memory. But there is where the problem started. I put all 4 modules in all 4 slots, they all started to shine nice RBG patterns, but after few reset on starting the computer, yellow LED on mobo for memory started to lit.

I put new 2x16Gb in A1 and A2 and worked fine. Then I put old 2x16 Gb in B1 and B2 and then I got yellow light again. I tried all combinations, new and old memories in A1 and in A2 everything works. But when I put one module in B1 or B2 or in both B1 and B2 I got yellow light again.

I did not changed anything in my bios. It is all on default values. I am not an overclocking kind of guy so I want to keep all to run smoothly. Only thing I did is to update bios to latest version, but that did not helped.
I am out of ideas.

Is it possible that mobo can handle 64GB of regular memory but only 32GB of RGB memory?
Does RGB feature limits capacity?
Instructions for my mobo says it can uses 64GB with 4x16GB non-RGB, but for RGB modules, all combinations are limited to 32 GB (2x16, 4x8 GB). Or maybe there is not enough power to memory? That's what I concluded... And finaly I found on Crucial site that all memory combinations for rgb memory https://www.crucial.com/products/gaming-memory are kits of two. Even 64GB is kit of two, not kit of 4. Anyone has experience with this?



Rgds

 

[Darkbreeze]

I know my motherboard support up to 128GB 4666MHz of RAM in 4 slots, but nothing in B1 and B2 works.

This is what Asus said:
"Regarding the below described case, we kindly inform you that the RAM modules with the referred part numbers have not been officially tested by Asus with your product and therefore compatible to it. "
My question is how then 2 dimms in A1 and A2 works but not in B1 and B2 slots?

This is reply from Kingston, I told them of what my motherboard is and sent them photos of my memories:
"It is unfortunately not possible to install 64GB modules as this is not supported by your system. "
My question is what they mean 64GB modules AS THIS IS NOT SUPPORTED?

To begin with, you are not even using the correct DIMM slots for pairing. Forget anything you THINK you know from the manual, because you are not reading it correctly. It, and all other manuals, are typically misleading when it comes to memory population rules EXCEPT for in the visual diagrams which show actual population.

For two DIMM population you should be using the A2 and B2 slots, which are the second and fourth slots from the motherboard. If you have two matching DIMMs, those are the slots you want to install your memory in. Not any other combination of slots. It does not even matter WHAT motherboard it is. If it is a dual channel motherboard, whether AMD or Intel, from the last ten to fifteen years, you use the second and fourth slots over from the motherboard, Period.

If you are using four DIMMs that consist of two different two DIMM kits, then you would want to put one set in the second and fourth slot, A2 and B2, and one set of matching sticks in the first and third DIMM slots over from the CPU, which are A1 and B1. Confusion exists because motherboard manuals are misleading due to unexact terminology. When it comes to memory population, the second and fourth slots make up one half each of a dual channel configuration. Putting both sticks in the SAME channel, does not result in dual channel operation. So, matched set in A2 and B2. Matched set in A1 and B1.

If you have them installed that way and it still doesn't work then you have one of four problems.

Either there are bent pins on the motherboard, or the CPU cooler is improperly installed and is cinched down tighter in one corner or on one side than the other and is cocking the CPU in the socket or for some other reason the CPU is not seating correctly, or the motherboard is bad. It's also possible that either the memory is not compatible with your motherboard, and not all memory is compatible with all motherboards, or one or more DIMMs are simply faulty.

That is assuming you do in fact have a BIOS that is up to date. Reading over your initial post I see that you tried using the A2 and B2 slots, only, when you had just two DIMMs, and it didn't work. That tells me either the memory is not compatible or there is a physical problem, like a bent pin on the CPU, maybe a standoff in the wrong place under the motherboard. Could be an issue with the installation of the CPU cooler. We've seen many occasions where that has caused memory issues because it cocks the CPU in the socket and breaks one or more of the contact points from making contact.

Usually though, this is either incompatible memory or a bad motherboard.

Personally, I dislike Kingston because they don't offer a memory compatibility validation chart or utility AND I often find Kingston memory to not be compatible with a number of motherboards. Intel is usually pretty forgiving in this area though, unlike AMD. Still, if the memory won't work in the A2 or B2 slot then something is not just "not working", it's plain wrong. Something IS wrong if you have to use other slots to get them to work and they will not be working in dual channel unless they are installed in A2 with B2 or A1 with B1. On many boards, A1 with B1 won't work unless the other two slots are already populated.

 

[Superfrog79]

I got new motherboard and all 64GB are now detected. It was that bent pin which caused the problem.

 

[Darkbreeze]

Well, like I said, it had to be a physical problem of some kind if the A2 and B2 slots wouldn't work. A bent pin would certainly do it and that certainly falls under the "broken motherboard" category.

Glad you got it figured out man. Good luck.

 

[cmulllett]

Just wanted to add - had a strange issue where only 2 sticks of RAM out of 4 were working. After swapping out and test each individually ended up with none working. Started to worry it was the MB, so checked with a different set, no joy.
Started to panic - and then read this thread.
Reset the CMOS. No joy.
Took the CPU out, checked for bent pins, could see any. Gave it a really good blow and then re-seated the CPU.
I think there must have been a hair or something, as after that it all worked perfectly! Thanks SkyNetRising for suggesting checking the motherboard: if you google about failed RAM/RAM slots no one mentions that!

 

[Darkbreeze]

no one mentions that!

Any knowledgeable tech or builder would always mention that if questions regarding memory come up since on all modern Intel and AMD platforms the memory controller is IN the CPU. If you look at the best answer for this thread, I clearly state that a cocked CPU or any CPU that isn't seating correctly, can cause memory problems.