Asynchronous mode alternatively best works when two non-same SODIMM’s are mounted, non-equal within the sense that they vary in capability, as an instance 1x 1GB and 1x2GB = 3GB.
Regardless whether you have an older DDR memory pc or newer DDR2 or DDR3 laptop, always try to install SODIMM’s of the same ability. Doing so will ensure your reminiscence (where your pc helps dual channel mode) runs in synchronous mode.
when you have a DDR2 or more moderen computer that helps dual channel mode and installation non-equal capacity SODIMM’s, this may force asynchronous mode. In such situation, handiest part of your reminiscence will function in twin channel mode, the opposite component will run in unmarried channel mode.