DDR3 Memory and Motherboard Compatibility

December 1, 2009 12:58 PM

Question about DDR3 Memory and motherboard compatibility DDR3 speeds include: 1066, 1333, 1600, 1800, and 1866 (I am leaving out 2000's series). The motherboard I am looking at has the memory standards of DDR3 1800 (OC)/1666/1333/1066. Question: What is DDR3 1666? Assuming the port is compatible, will DDR3 1600 work with this board?
posted by jbreyfogle to Computers & Internet (4 answers total)

Most RAM modules are capable of operating at lower speeds than they are rated, to a point. In general, if the RAM will physically fit in the board, it'll work, provided the board can recognize that much RAM and it's appropriately ECC/non-ECC. The RAM will automatically be scaled down to its best allowable speed, whether the limitation is imposed by the board or other RAM modules.

In general, DDR goes up to 400, DDR2 fom 400 to 800, and DDR3 from 800 to 1600.

AnandTech has a detailed discussion about DDR2 v. DDR3 here.
posted by valkyryn at 1:25 PM on December 1, 2009

I'm pretty sure that small a difference won't matter, especially since your motherboard will be clocking the RAM at a speed slower than its rated for. Overclockers often try to run RAM at higher rated speeds to get more memory bandwidth and higher clock speeds for their CPUs. I'd be really surprised if you ran into an issue.
posted by mccarty.tim at 1:28 PM on December 1, 2009

The best bet is to check the Motherboard manufacturers website and see what RAM is tested and verified compatible with the board.
posted by ijoyner at 10:05 PM on December 1, 2009

Mostly likely 1666 is either a convenient number for overclockers to achieve or a typo. Typos are quite frequent in this sort of nitty-gritty technical stuff.
posted by chairface at 4:29 PM on December 4, 2009