E2 Drive Form Factor

Overview

The E2 drive form factor is the EDSFF enterprise SSD form factor that Meta prefers for its next-generation high-density QLC storage servers. Compared with multi-PCBA designs that rely on flex connectors, E2's simpler single-PCB construction provides better cooling capability and avoids repeated chassis redesigns as drive density grows. Meta's rationale is driven by scaling limits: E3.S tops out at about 128TB and cannot scale beyond, whereas designing to E2 retains optionality because any E3 drive also fits an E2 slot. Meta therefore plans to build future servers to E2 while keeping the flexibility to deploy E3 drives, targeting the 128TB and 256TB capacity points. The shift is reinforced by thermal simulations showing corner-case throttling at 256TB U.2 / 300TB DFM densities, where the better-cooled E2 form factor becomes preferable.