DDR3 in DDR3L slot

[aeadespeacock]

I’ve just purchased this refurbished HP Elite book 840 G2, Now the machine came with one stick of DDR3L ram, however when I inserted a 4GB DDR3 (Not DDR3L) stick from my old Laptop (Dell Latitude E6420) the HP came up with an error message upon booting explaining that I had inserted an incompatible DDR3 ram type however the laptop still proceeded to boot and seems to work alright regardless. So does this mean that it’s okay to continue to use the machine like this? Or will it damage/reck it?

[Letgomyleghoe]

It’s probably just not attempting to access that memory, there’s probably not even enough energy supplied to power that stick.

[Sakkura]

DDR3L is just DDR3 at 1.35V. Usually they're intercompatible, but you'd want to make sure the DDR3 isn't running at an elevated voltage (some kits run at 1.65V rather than usual 1.5V, and that may be too aggressive on a system intended for 1.35V).

[JakeSublime]

I have personally gone through this whole process. I have a pc with a cpu that requires low energy ram (1.35v), but i slapped it with 20GB of regular 1.5v ddr3 ram. It ran fine for about 2 years until i started to have cpu problems. After many hours of ripping my hair out, i pinpointed the issue to be within the cpu itself. I was able to contact intel and have them warranty replace that i5 free of charge. I slapped it with the new i5 and its been running fine since then, about 2 years ago (Its possible that i had a defective cpu, but i think it was my using 1.5v ram).

 

Are you running the laptop with both the ddr3 and the ddr3l sticks installed? If yes, check task manager to see if your ram is equivalent to both sticks of ram combined. If this checks out, check in the bios or some type of system monitor to see if the ddr3 ram is running at 1.35v or 1.5v (its likely running at 1.5v).

If your system is utilizing all the ram AND both the ram voltages are at 1.35 then youre solid. 
If your system is utilizing all the ram BUT one or both the ram voltages are at 1.5 then the laptop will probably be okay, but likely with reduced lifetime.

If your system is NOT utilizing the ddr3 ram, then it requires ddr3l ram and theres no (friendly) way around this. 

Last thing, i highly recommend against using ddr3 ram in a system that asks for ddr3l ram. You WILL put higher stress on internal components, and you WILL reduce the lifetime of your mobo/cpu (although i have and am still currently doing this ).