DIGIT-ARC read-only archive · snapshot: July 23, 2026

Ram related query

8 posts · originally from https://geek.digit.in/community/threads/ram-related-query.193374/

digibrush
digibrush Original post #1
Aug 26, 2015 at 8:39 AM
Is it safe to use two different speeds RAM sticks ?

currently I am using 2 sticks of corsair 4gb (1600), I want to add my unused 2x2gb corsair 1333 on the other 2 slot. Surely 1600MHz down to 1333.
question is should I use it?
topgear
topgear #2
Aug 26, 2015 at 9:21 AM
Yes, you can use it .
kg11sgbg
Aug 26, 2015 at 12:09 PM
Is it safe to use two different speeds RAM sticks ?

currently I am using 2 sticks of corsair 4gb (1600), I want to add my unused 2x2gb corsair 1333 on the other 2 slot. Surely 1600MHz down to 1333.
question is should I use it?
Yes,as marked by @topgear,you can surely use it.
Always look out for the Voltage compatibilities within RAM modules,whether its 1.5v or 1.35v.
In case of laptops,these volts are the most important criterion than any thing else in RAM selection.

But in case of Desktop PC(desktop RAM modules),is there such relaxation in voltage selection?
I mean will a 1.5v RAM module(Desktop) and 1.35v Ram module(Desktop) be compatible with each other?

Friend @topgear,please explain.
digibrush
Aug 26, 2015 at 1:00 PM
Yes, you can use it .

Thanks for your support.

Yes,as marked by @topgear,you can surely use it.
Always look out for the Voltage compatibilities within RAM modules,whether its 1.5v or 1.35v.
In case of laptops,these volts are the most important criterion than any thing else in RAM selection.

But in case of Desktop PC(desktop RAM modules),is there such relaxation in voltage selection?
I mean will a 1.5v RAM module(Desktop) and 1.35v Ram module(Desktop) be compatible with each other?

Friend @topgear,please explain.

Thanks too.

These are screenshots(HWiFO64) after installing 2 sticks of 2gb.

*i.imgur.com/T7Cbmdy.jpg
topgear
topgear #5
Aug 27, 2015 at 9:42 AM
[MENTION=102635]digibrush[/MENTION] - Post a cpu-z screenshot of the Memory tab.

Yes,as marked by @topgear,you can surely use it.
Always look out for the Voltage compatibilities within RAM modules,whether its 1.5v or 1.35v.
In case of laptops,these volts are the most important criterion than any thing else in RAM selection.

But in case of Desktop PC(desktop RAM modules),is there such relaxation in voltage selection?
I mean will a 1.5v RAM module(Desktop) and 1.35v Ram module(Desktop) be compatible with each other?

Friend @topgear,please explain.

Desktop ram modules are more flexible I believe. A 1.5v module can run at both 1.65v and 1.35v depending on the chip type, manufacturer support and of course on the hardware it's going to be used. So using a 1.35v module with 1.5v module should work together if the ram module and bios are flexible enough.
kg11sgbg
Aug 27, 2015 at 9:40 PM
@digibrush - Post a cpu-z screenshot of the Memory tab.



Desktop ram modules are more flexible I believe. A 1.5v module can run at both 1.65v and 1.35v depending on the chip type, manufacturer support and of course on the hardware it's going to be used. So using a 1.35v module with 1.5v module should work together if the ram module and bios are flexible enough.
Thanks Boss [MENTION=15026]topgear[/MENTION], this was the answer which I reckoned. Updated BIOS with a good hardware supported motherboard could do the trick.

But in case of Laptop/Notebooks it is a strict NO-NO situation.
topgear
topgear #8
Aug 28, 2015 at 2:28 PM
^^ Not always. Standard JEDEC voltage for ddr3 ram is 1.5v but haswell laptop cpus only supply 1.35v to the ram module. So 1.5v ram module may work or not on a haswell laptop if the memory does not run with 1.35v but if it does than the laptop should work fine. That's why many manufacturers are now coming up with dual voltage ram modules which are certified to work with both 1.5v and 1.35v.