PCIe AIC vs. U.2
Comparing 2 standards across 7 specifications. 7 key differences identified.
PCIe Add-in Card (AIC) SSDs, commonly called HHHL (Half-Height, Half-Length), plug directly into a PCIe expansion slot like a graphics card rather than using M.2 or U.2 connectors -- trading compactness for the far greater power delivery and cooling surface area a full expansion card provides.
U.2 uses the SFF-8639 connector to bring PCIe x4 NVMe speeds to a 2.5-inch, hot-swappable drive body -- the enterprise and datacenter counterpart to consumer M.2, trading M.2's compact size for better cooling, higher power delivery, and the ability to swap drives without powering down.
Specification Comparison Table
7 Parameters| Parameter / Spec | ||
|---|---|---|
|
Physical Form Factor
|
Half-Height, Half-Length (HHHL) PCIe expansion card | — |
|
Slot Power Available
|
Up to 75W (PCIe x16 slot) | — |
|
Typical Use
|
High-performance enterprise/datacenter and enthusiast drives | — |
|
Connector
|
— | SFF-8639 |
|
Max PCIe Lanes
|
— | x4 (same NVMe electrical spec as M.2 M-key) |
|
Power Rails
|
— | 3.3V, 5V, 12V (vs. M.2's 3.3V only) |
|
Hot-Swap
|
— | Yes |