What each one does
DRAM (DDR5, DDR4, LPDDR, HBM) holds data while a system runs and loses it when power is cut. NAND flash (TLC, QLC, SSDs, eMMC, UFS) keeps data without power. DRAM is fast and costly per bit; NAND is slower and far cheaper per bit.
The supplier bases overlap but differ. Samsung, SK hynix and Micron dominate DRAM; NAND adds Kioxia, SanDisk and YMTC. That difference shows up in how quickly each market reacts to demand.
Cost per GB right now
DDR5 16Gb die: $55.770 per die, $27.89/GB (derived). TLC NAND 512Gb die: $20.000 per die, $0.313/GB (derived). The statistics table carries 30-day and year-over-year change for every line, including QLC and a finished client SSD.
Why the cycles are diverging
DRAM is tied to AI through HBM: wafers converted to HBM come out of the commodity DDR5 and DDR4 supply, so AI demand tightens DRAM directly. NAND benefits from AI mainly through enterprise SSDs for training data and inference caching, which is a real driver but does not remove consumer supply the same way.
The downside is clearer on NAND. TrendForce's September spot updates show TLC wafer prices easing for three weeks on weak consumer demand, even while enterprise SSD contracts stay firm. Retail SSD prices usually follow wafer spot with a lag of one to two months.
What to watch
For DRAM: DDR5 spot inquiry volume and any slowdown in HBM wafer conversion. For NAND: whether enterprise SSD contract strength can offset consumer softness, and supplier capex. A higher layer count per wafer raises bit output without new fabs, so NAND supply tends to come back faster than DRAM supply.