Firstly, the annotation GB
is not equal to Gb
. The first is gigabytes, the second gigabits. Bits typically are used to measure speeds, bytes to measure storage, although that obviously isn't a guarantee as they can be converted, but is the case here.
Unfortunately the term gigabyte is ambiguous, as it can be a decimal or binary calculation. This means in some instances a gigabyte can be either 1000000000 bytes, or 1073741824 bytes. The term gibibyte (GiB) always refers to the latter, and typically RAM manufacturers use this value when referring to capacity.
The RAM in question has a capacity of 32GB in total. This means, however long it takes to do it, it cannot hold more than 32 gigabytes of data at any one time. The throughput is a factor in determining how quickly this data can be accessed.
The maximum throughput will be handled by the memory controller, which may be a feature of the CPU (Core i series for example) or of the chipset on the motherboard northbridge on older boards. For your example, you'd need to check the cpu supported DDR4 2666MHz modules.