Specifications

Every value in the table is from the vendor’s own HiFive Unmatched datasheet (the HF105 datasheet), cross-checked where possible against the HiFive Unmatched Software Reference Manual v1.1, the Freedom U740-C000 Manual v1.7, and independent hands-on coverage from Phoronix (2021) and HotHardware (2024). The Freedom U740-C000 Manual is a chip-level document — it describes the SoC, not the board — but the Unmatched is built directly on that SoC, so its core, cache, and boot-process detail apply.

The two board generations share this table. The original HiFive Unmatched and the later HiFive Unmatched Rev B use the same FU740 SoC and the same firmware; Rev B’s differences are in power management — it starts on its own when power is applied and can be powered off in software, aimed at unattended and cluster use — not in the specifications above.

Ordering codes, per the datasheet: HF105-000 is the retail kit (board, 32 GB microSD, Mini-ITX I/O shield, cabling, and mounting hardware); HF105-OEM is the board and SD card only. The accessories to expect therefore depend on which SKU a given unit came from.

Claims that disagree or rest on a single source

• CPU clock: 1.2 GHz shipped, not the 1.4/1.5 GHz of the announcement. SiFive’s launch-week announcement (October 2020) said the board would ship at 1.4 GHz with headroom to 1.5 GHz, reported independently by CNX Software and LinuxGizmos. The vendor’s own shipped documentation disagrees: the datasheet states 1.2 GHz, and the software reference manual gives the same 1.2 GHz as the U74 PLL frequency configured in U-Boot SPL. HotHardware’s 2024 review measured 1.2 GHz as well, three years on. The FU740 chip manual puts 1.5 GHz inside the silicon’s envelope, so the higher numbers are reachable, but 1.2 GHz is what the shipped board is documented and observed to run. The table carries the shipped figure.

• Memory: announced at 8 GB, shipped at 16 GB. At the October 2020 announcement the board was specified with 8 GB of DDR4-2400. Crowd Supply’s 10 December 2020 update doubled it to 16 GB for all kits at no extra cost, a change SiFive’s own Freedom-U-SDK release notes corroborate from the software side and every post-shipping review confirms. The 16 GB in the table is the only configuration that reached backers.

• USB port count. The datasheet’s own “External Connections” list names “2 × Stacked USB 3.2 Gen 1 Type A Connectors,” while the same datasheet’s summary, SiFive’s current product page, and both independent hands-on reviews describe 4 × USB 3.2 Gen1 Type-A. The most likely reading is that each stacked connector housing carries two ports, giving four in total, but no source spells that reconciliation out, so the table follows the four-port figure that the majority of sources use.

• Schematics licensing. SiFive publishes a full schematic set for the original board, but unlike its CC-licensed manuals and BOM the schematics carry only a “© 2021 SiFive, Inc.” notice with no explicit licence grant. It is therefore linked from the overview rather than mirrored here, and treated as all-rights-reserved until SiFive says otherwise.

• Retail availability could not be fully verified. Crowd Supply’s live listing (checked 2026-07-03) shows only Rev B, In Stock at $740; the original board is no longer sold there. HotHardware’s October 2024 review quoted Rev B at $299, more than a hundred dollars below the Crowd Supply price, and no source explains the gap — a promotional price, a channel difference, or a later increase are all possible but none is confirmed. Mouser is SiFive’s other named channel for Rev B, but Mouser’s product page blocked every fetch in this pass, so its current stock and price are unverified. A separately reported claim that Crowd Supply cancelled remaining original-board preorders in early 2022 rests on a single article that could not be read directly, and is recorded here as unconfirmed rather than stated as fact.