Typically commercial RAM has a temp range of 0 to 85degC. In the olden days, you constrained your IO timing on the device/chip that drove the ram so that it wor

Typically commercial RAM has a temp range of 0 to 85degC. In the olden days, you constrained your IO timing on the device/chip that drove the ram so that it worked at all temperatures at the rated speed. (Well, unless you were a 90s graphics card integrator...) Now, at least since DDR3, PVT variations are continually calibrated out at runtime. So as the temp goes up, you still get periodic, quick recalibration. DDR4 and now 5 have even more extensive compensation to keep the electrons flowing at the edges of our current ability. Did you know that GDDR5 has had the ability to CRC data bursts since 2008? Now it's come down to normal memory.