Question Placing ram sticks

[rtadd]

This has probably been asked before but I couldn't find a straight answer.
I've added more ram to my pc. It originaly had 16 GB (8x2) of ddr4 3200 MHz, and I got another two sticks of the same brand, but the chips must have been slightly different because the timings weren't exactly the same. When I enabled xmp the pc wasn't stable until I manually set those timings equal to the ones on the slower sticks. So fortunately the pc is working fine now.
The thing is that when I installed the new sticks I had one available slot on each channel, so each channel now has one of each "type" or ram (one new and one old). Would it be better if I put the 2 old sticks in one channel and the new ones in the other?

 

[scout_03]

both name and model of the ram kits .

 

[rtadd]

Crucial vengance lpx, both of them.

EDIT: here's some more information. Both are 3200 MHz, the firt kit's timings are 16-20-20-38, second kit 16-18-18-36.
As I said, xmp defaulted to the second's kit timing and the system wasn't stable. But with the first kit's timings it's working fine.

 

[geofelt]

You are fortunate in that only a minor change was needed.
Often added voltage is needed for stability.

Since things are working, do not change anything.


Run memtest86 or memtest86+
They boot from a usb stick and do not use windows.
You can download them here:

MemTest86 - Official Site of the x86 Memory Testing Tool

MemTest86 is the original self booting memory testing software for x86 and ARM computers. Supporting both BIOS and UEFI, with options to boot from USB.

www.memtest86.com

Memtest86+ | The Open-Source Memory Testing Tool

Memtest86+ is an advanced, free, open-source, stand-alone memory tester for 32- and 64-bit computers (UEFI & BIOS supported)

www.memtest.org

If you can run a full pass with NO errors, your ram should be ok.

Running several more passes will sometimes uncover an issue, but it takes more time.
Probably not worth it unless you really suspect a ram issue.

 

[rtadd]

Thanks for the suggestion!
I did run memtest86 and fortunately everything was ok.
However, my question remains... let's say that my pc didn't pass the test, or that I kept having stability issues trying to enable xmp, would it have helped if I had put the two sticks of each kit in the same channel?

And maybe I'm going offtopic with this but... from what I understand, when you have mismatched ram they will always run at the speed of slowest one. So why did xpm set the timings to the one that was (a little bit) faster? Does it make sense that changing from 16-18-18-36 to 16-20-20-38 made my system stable?

 

[geofelt]

XMP is settings embedded in the ram chip itself.
The settings would have been retrieved looking for the first stick that the motherboard could find.

 

[rtadd]

Ok... the it's not as automatic as I thought. If I had a 3600 mHz stick in the first slot the motherboard would have selected those parameter for the xmp and it would have never worked.

And I'm sorry if I keep insisting on this... but so far I haven't had an answer to my original question. If I have 2 different kits of ram, is it better to put both sticks of the same kit in one channel or mixing them?

 

[geofelt]

Ok... the it's not as automatic as I thought. If I had a 3600 mHz stick in the first slot the motherboard would have selected those parameter for the xmp and it would have never worked.

And I'm sorry if I keep insisting on this... but so far I haven't had an answer to my original question. If I have 2 different kits of ram, is it better to put both sticks of the same kit in one channel or mixing them?

I know of no reason why one method would be better than the other.
Take your pick.