Memory overclocking oddity

[Nagasaki]

I have been messing about with overclocking my ram of late after using the new CTR program to get the most out of my R5 3600. I got 4.4Ghz at 1.168v Runs nice and cool.

 

So the memory thing.

 

I have 2 kits of Corsair Vengeance RGB 3000Mhz CL15 16GB. One kit is newer than the other I am assuming by the version number on the sticks. One kit is v5.32 and the other v5.39 iirc

 

The 5.32 kit will not no matter what timings or voltage I give it, overclock past 3200Mhz. It flat out refuses to work.

 

The other kit will OC up to 3733/66 but not quite stable. I have settled at 3600Mhz for now at 16-18-18-38 (Stock is 15-17-17-36)

 

All fine so far. The weirdness kicks in when I use dimm slots 1 and 3 vs 2 and 4.

 

In 2 and 4 my ram will run at 3600Mhz fine but in slots 1 and 3 I cant get past 3200Mhz.  Would this be the memory controller being a pain or the mobo?

 

I went back and tested the kit of ram that would not OC past 3200, one stick in one slot at a time and it would not go past 3200Mhz in any slot.

 

The newer kit that does OC to 3600Mhz would not go past 3200 in slot 1 and 3 but worked at 3600 in slot 2 and 4

 

All seems very odd to me!

 

Thoughts?

 

 

I am planning on getting a better kit of ram soon, 32GB 3600Mhz+ as I hope to switch from my aging x370 mobo to a B550 of some sort and then get a new 5600x at some point soon

[emosun]

4 minutes ago, Nagasaki said:

All seems very odd to me!

well the ram is rated at a 3000mhz overclock so if you're going even up to 3001 all bets are off when it comes to stability. I really wouldnt expect it to run any better than it's rating , and the actual endgame results of a 200mhz overclock isn't going to be that amazing to justify no stability anyway.

[Letgomyleghoe.]

Some memory chips just won't overclock and with a bin like3000mhz cl 15 you will get whatever was in the factory that day which I assume wan't very good if it does go past 3000mhz at all

[Jurrunio]

The kit is rated for 3000C15 minimum, no maximum limit. It can be very good or very bad.

 

As for which slot works better, you are meant to use slot 2 and 4 first and daiy chain topology boards do care about which slot per channel you're using. Unlike T-topology, which does not care that much.

[Nagasaki]

Ok ok, missing the point here a little.

 

What I am getting at here is why does 1 memory channel overclock better than the other?

 

I don't want to buy, say 4x8gb sticks running at 3600Mhz only to find that one of the memory channels wont run at that speed for some reason.

 

I am trying to narrow down if its the mobo, the ram or the CPU... I am getting my hands on a 3900X soon so I guess I will find out then. I will also be getting a B550M mobo soon as well so i can upgrade again to the 5000 series at some point.

[MisterMeow]

On 11/16/2020 at 11:32 AM, Nagasaki said:

All fine so far. The weirdness kicks in when I use dimm slots 1 and 3 vs 2 and 4.

So the problem is your motherboard. You're using a board that is likely using a daisy chain topology. With that topology, you want to use slots 2 and 4 for the best results. Also, that topology struggles a bit more with a 4 dimm configuration. So your best config is always going to be a 2 by in slots 2/4. With all 4 slots populated, you have a second slot in each channel which interferes with the signal.

 

But the kit that won't go past 3000mhz at all is probably a bad bin on top of it. So either use a 4x8 config at 3000C15, or go for the better bin 2x8 with the overclock.