Question Very specific question about ram mixing

Jaga848

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Jan 1, 2014
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I have quite a specific situation I want to ask about.

My motherboard is gigabyte b250 hd3p. The RAM slots channels are (when looking from left to right) AABB, or DDR4-4, DDR4-2, DDR4-3, DDR4-1, with 4 AND 2 BEING CHANNEL A, and 3 AND 1 BEING CHANNEL B.

I currently have 2x4gb sticks of Kingston HyperX Fury RAM running in dual channel mode (put in the DDR4-2 and DDR4-1 slots).

I found a really good deal for another 2x4gb sticks with the exact same model number, timings, latency, and exact same revision number. I am aware that this is often a gamble, but I want to try.

My question is: should I put the NEW ram into the remaining slots available (slots DDR4-4 and DDR4-3)? - in this case in channel A slots there would be 1 stick of the NEW ram I bought and 1 stick of the OLD ram I currently have, and the same would also apply to channel B.

OR should I make the configuration in a way that the OLD ram I currently have populates only channel A slots, and the NEW ram I bought populates only channel B slots?

OR does it not matter?

I hope I am being clear, if something is confusing I'll try to clear it up.

Thanks in advance!
 

boju

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Doesn't really matter which slots, if they all work together then good. If not, then swapping them around might be a troubleshooting step.

First try leave old ram where they are and put new sticks in the vacant slots.

Dimm slots from cpu; New, old, new old.

Troubleshooting; Old, new, old, new.

If unlucky in your endeavour and they don't play nice together, trying to configure memory manually instead of using XMP with perhaps at a slower speed, relaxed timings (& command rate of 2T) and slight bump in dram voltage would be things to try. If it came to this and system doesn't boot with all four, configure the bios with a working set then try your luck with all afterwards.
 

Jaga848

Honorable
Jan 1, 2014
27
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10,540
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Doesn't really matter which slots, if they all work together then good. If not, then swapping them around might be a troubleshooting step.

First try leave old ram where they are and put new sticks in the vacant slots.

Dimm slots from cpu; New, old, new old.

Troubleshooting; Old, new, old, new.

If unlucky in your endeavour and they don't play nice together, trying to configure memory manually instead of using XMP with perhaps at a slower speed, relaxed timings (& command rate of 2T) and slight bump in dram voltage would be things to try. If it came to this and system doesn't boot with all four, configure the bios with a working set then try your luck with all afterwards.
It's Kingston HyperX RAM which doesn't need to have XMP turned on because it uses plug n play and determines the best timings out of the box. However, I have a question:

CPU-z already shows command rate of 2T even with only 2 sticks of ram, is this normal or not? Everything is set to AUTO in bios.
 

Jaga848

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Jan 1, 2014
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boju

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Roger. Your ram has XMP 2400 profile, are you sure XMP isn't enabled? Because i see CL15 under memory tab and spd shows XMP profile for CL15. Normal Jedec 2400 profile has CL timing of CL16.

Does command rate change to 1T if enable XMP?
 

Jaga848

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Jan 1, 2014
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Roger. Your ram has XMP 2400 profile, are you sure XMP isn't enabled? Because i see CL15 under memory tab and spd shows XMP profile for CL15. Normal Jedec 2400 profile has CL timing of CL16.

Does command rate change to 1T if enable XMP?
Nothing changes in cpu-z if I enable xmp, all the values are exactly the same.

Here you can see from the specification of my ram that JEDEC/PNP has the same values as XMP.

https://ibb.co/yXgChnB
 

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