Dual channel vs single channel memory

Single oder dual ram

Generally one group is located

Ultimately for servers, rank comes down to density. Four ranks one quad-rank, two dual-rank or four single-rank will demand to lower memory speed on one step making total productivity about the same as with the only single-rank module.

It can be said that you exchange memory speed on memory volume. The channels are read alternately, one being read into the buss while the other is being prepared for use, or being written to.

The main idea behind memory

These two groups can be laid out on the stick in any configuration the manufacturer wants. Same as with memory banking, the more modules ranks you install, the slower memory speed is allowed. The main idea behind memory ranking - to staff more memory into a single-slot module, decreasing the needed banks number. Generally one group is located on each physical surface of the stick, but not always. These chips may be laid out on one or both sides of the stick, it doesn't matter.

These chips may be laid outThese two groupsSame as with memory banking

With a dual channel system, one channel is always available for loading, refreshing, and housekeeping while the other channel is being read. This makes the buffer onboard memory more critical and works it harder. For example, a server with four memory slots may be limited to a total of eight Ranks. Especialy with the internet rescources at your fingertips.

However, that is not why it is called double sided. So ranking can be quite important. It has the same limitation effect and, in principle, does not differ much. What exactly happens is the pervue of the memory controller and it's firmware. This means you can install four Single Ranked modules or four Dual Ranked modules but only two Quad Ranked modules, as installing more would exceed the amount of Ranks that can be addressed.