M386A4G40DM0-CPB comes in two different flavours - be aware!
Please be aware that all suppliers due to no fault of their own, rather due to Samsung part no. labeling, supply different parts under the same part no. When you check the Samsung memory website there are two parts, M386A4G40DM0-CPB0 & M386A4G40DM0-CPB2 and they are distinguished by a controller chip from IDT and one from Montage respectively. This also leads to timing differences. So when ordering check this out other wise, if its critical, you may end up with memory sticks of varying timing characteristics.
Otherwise this memory works fine in my workstation. Just which Samsung fully labels their parts as per their spec sheets.