Different RAM voltages?

[Griffin031]

o, i'm getting a free gift of 8gb of ram which is at 1.35V, but ram i'm now using is 1.2v. I asked and searched today a bit and got like 25 different answers to my question, is it okay to use them both? Should i undervolt 1.35 one or overvolt 1.2 one or leave them be as they are and could they damage my mobo if i plug them both in? Ty in advance.

 

P.S. Skip the "just buy another kit don't risk" and similar answers please, i'm looking for answer to this question i asked

[porina]

What is the ram you have, and are getting, for what system?

 

For example, in DDR4 era, standard ram is 1.2V but higher performance XMP kits were 1.35 or more. If you don't turn on XMP then chances are the 1.35v ram will run at lower speed and 1.2v. Alternatively 1.2v ram will run at 1.35v too.

[Alex Atkin UK]

44 minutes ago, Griffin031 said:

o, i'm getting a free gift of 8gb of ram which is at 1.35V, but ram i'm now using is 1.2v. I asked and searched today a bit and got like 25 different answers to my question, is it okay to use them both? Should i undervolt 1.35 one or overvolt 1.2 one or leave them be as they are and could they damage my mobo if i plug them both in? Ty in advance.

 

P.S. Skip the "just buy another kit don't risk" and similar answers please, i'm looking for answer to this question i asked

The safest option is to run both as 1.2, but mixing completely different RAM can cause a whole bunch of other issues.  It might not POST or you get crashes and you probably wont be able to use XMP.

[RONOTHAN##]

49 minutes ago, Griffin031 said:

is it okay to use them both?

There's nothing dangerous about it. The worst that could happen is that it's unstable with both sticks in the system, and there's only one way to find that out. 

 

49 minutes ago, Griffin031 said:

Should i undervolt 1.35 one or overvolt 1.2 one or leave them be as they are

I'm assuming they're DDR4 since these sound like DDR4 voltages. 1.2V is JEDEC for DDR4, so if you just stick them both in the system, they will both run at 1.2V at the speed of the slowest kit (probably 2133MT/s CL15). If you want to try and get them to the speed of the faster kit, you can try to do that as well, and in that case it's worth mentioning that by JEDEC spec all RAM much be able to stand 1.35V without being damaged indefinitely, so overvolting to 1.35V is perfectly safe. 

 

49 minutes ago, Griffin031 said:

could they damage my mobo if i plug them both in?

No. 

[Griffin031]

3 hours ago, porina said:

What is the ram you have, and are getting, for what system?

 

For example, in DDR4 era, standard ram is 1.2V but higher performance XMP kits were 1.35 or more. If you don't turn on XMP then chances are the 1.35v ram will run at lower speed and 1.2v. Alternatively 1.2v ram will run at 1.35v too.

it's a ddr4 ram 

2 sticks are on 2666mhz and one i'm getting is 3200mhz and 1.35v

mobo is z370 f strix

[porina]

10 hours ago, Griffin031 said:

it's a ddr4 ram 

2 sticks are on 2666mhz and one i'm getting is 3200mhz and 1.35v

mobo is z370 f strix

Adding one more will lead to unbalanced memory, part dual channel, part not. Best leave the new stick out unless you know you need the extra capacity for something.

 

If you put in the new stick:

Safe option: run both old and new sticks at 2133 or maybe a little faster at 1.2v depending on what they report. Basically turn off XMP and system will work it out for you.

Try it option at 1.2v: Set 1.2v, XMP off, set speed to 2666 manually (leave other settings) and test for stability. There is a risk the 3200 1.35v stick might not work at this speed and voltage.

Try it option at 1.35v: Set 1.35v, XMP off, set speed to 2666 manually (leave other settings) and test for stability. This should work. The extra voltage on the old modules shouldn't make any difference other than some increased power consumption.

Overclock option at 1.35v: Set 1.35v, if it lets you - turn on XMP, set speed to 3200 if not already. Test for stability. You will be overclocking the old 2666 sticks.

 

That's the short version.