3 ms·
When DDR5 was first introduced, there were only x8 chips. Because the DDR5 channels must have a width of 32, 36 or 40 bits, with x8 chips one had to use 40-bit
by adrian_b 3y ago
When DDR5 was first introduced, there were only x8 chips.
Because the DDR5 channels must have a width of 32, 36 or 40 bits, with x8 chips one had to use 40-bit channels, even if only 36-bit channels are needed, so indeed 10% of the memory capacity remained unused.
Meanwhile, about a year ago, at least Micron has also introduced x4 chips. There are such ECC UDIMMs, using both x8 and x4 chips, which waste no memory.
On the market there are both modules made only with x8 chips, which do not use a part of the memory, and modules with a combination of x8 and x4 chips, without unused memory.