NVIDIA using 19Gbps GDDR6X on RTX 3080 due to heat issues?

Igor's Lab did a little digging to discover why NVIDIA's GeForce RTX 3080 uses 19Gbps GDDR6X memory chips. Micron already has 21Gbps variants available, so that leaves some wondering why NVIDIA didn't opt for the fastest version.

A test of the heat output produced by the RTX 3080 seems to suggest that thermal considerations played a major role here. The 19Gbps chips are running close to the maximum junction temperature (Tj Max), a value that would be exceeded by the 21Gbps parts.

The takeaway here is that the heat produced from the card is quite huge with a TGP of 320 W, meaning that the cooling is quite a problem which NVIDIA managed to keep under control, however, the design decisions resulted in some possible performance loss. Instead of NVIDIA using Micron's faster 21 Gbps chips, they are forced to use the 19 Gbps variants. It is not like there would be supply issues as NVIDIA is Micron's only GDDR6X customer, however, the real reason is heat management.

Via: TechPowerUp