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Low voltage v Normal RAM (Mixing?)

Posted: Thu Dec 29, 2016 8:17 am
by blink
Hope everybody had a good xmas.
Just bought a couple of 4gb ram sticks off ebay. 1 is the standard 1.5v the other 1.35v.
Just running memtest on them now in my x220.
Any opinions/experience on mixing & matching & advantages/disadvantages of both types? stability etc.
Will the low voltage only work on later model TPs?

Many Thanks

Re: Low voltage v Normal RAM (Mixing?)

Posted: Thu Dec 29, 2016 10:30 am
by creshal
There's a difference between "low voltage" DDR3 RAM (which supports 1.5V by default and 1.35V via separate SPD entry) and DDR3L.

The X220 will work with low voltage DDR3, by ignoring the 1.35V mode and driving it with 1.5V. DDR3L will not work.

Re: Low voltage v Normal RAM (Mixing?)

Posted: Thu Dec 29, 2016 1:59 pm
by blink
Thanks creshal it passed memtest ok & the appears laptop boots fine with it. it says pc3l or appears to be be ddrl3 not sure

https://www.micron.com/parts/modules/dd ... 8D2969B%7D

Dont want to use it though if their is a risk of damage or stability issues?

Re: Low voltage v Normal RAM (Mixing?)

Posted: Fri Dec 30, 2016 11:39 am
by Kasm279
PC3L/DDR3 Low Voltage modules are designed, per JEDEC, to also support 1.5V operation. Generally they don't mix well with normal-voltage DIMMs, but if it works you should be fine.