1666mhz ram on 1333mhz Motherboard


Jan 29, 2018
My friend is giving me a 4gb DDR3 1600mhz crucial ram for my PC,the thing is that I have a lenovo 2gb DDR3 1333mhz already in the system,so will the new ram work with the old.

My motherboard is a lenovo mtq45mk,it has a core 2 duo 3.0ghz CPU.

I just need to know if the 4gb 1666mhz of ram will work on my motherboard with the already installed 2gb 1333mhz of ram.
Can't hurt to try it if it's free. However note that the Q45 chipset supports only up to 2Mbit DDR3 chips so any 4GB stick must have 16 chips on it. Sandy/Ivy bridge can accept 4Mbit so can have only 8 chips on a 4GB stick, and modern high-density RAM is 8Mbits = 1GB per chip.

It's pretty difficult to find such low-density DDR3 nowadays unless you buy used vintage stuff from 10 years ago (which was mostly 1066 PC3-8500), and most 1333Mhz sticks will not be these. However oftentimes a higher density stick will work but only at half the rated capacity, so that 4GB stick might actually work but be detected as a 2GB stick. If that's the case, you might double your RAM and even run it in dual-channel!

Unless you are using the IGP though, a single channel of DDR3-1333 already fully saturates the 1333 FSB of your 3.0GHz processor. But 4GB is a big improvement over 2GB.