Server Parts: Caddies, Controllers and What They Cost

Prices updated 2026-08-14

Drive carriers by generation

Storage controllers

The card that ships in a used server decides whether the operating system sees raw disks or RAID volumes, and that single fact determines whether the machine suits ZFS, TrueNAS or Unraid. We track 11 cards across the Broadcom, Dell and HPE lines, each labelled for whether it is a host bus adapter by design, a card the community flashes, or a hardware RAID controller that is none of the above.

The card decoder and counterfeit checks · IT mode explained for ZFS and TrueNAS

Why the parts layer is where used-server builds go wrong

The arithmetic of a used enterprise server is seductive and slightly misleading. A twelve-bay chassis for a few hundred dollars looks like the whole purchase, and it is not. Between that machine and a working array sit a set of parts that individually cost very little and collectively cost enough to change the decision — and which, unlike the server itself, are boring enough that nobody blogs about them.

Carriers are the clearest example. A chassis arrives, the bays look full, and what is actually in them is blanks: solid fillers whose only job is to keep the airflow path closed. They have no rails and nowhere to mount a drive. Twelve carriers at ten dollars each is a hundred and twenty dollars nobody budgeted, and it arrives as a surprise on the day you were planning to build.

The storage controller is the more consequential one, because getting it wrong is not a delay but a design error. A machine that ships with a hardware RAID card will run perfectly well and quietly deny ZFS the per-disk visibility it needs to do the one thing people choose ZFS for. That is a question to settle with a seller before money changes hands, and it costs one line in a message.

Cables are the third and smallest. A controller terminates in a specific connector — SFF-8643 on 12Gb/s-era hardware, SFF-8087 on 6Gb/s-era — and the backplane expects a matching cable. They are a few dollars and they stop a build dead if you have the wrong one, which is a poor use of a weekend.

How we source what is on these pages

This category has a specific honesty problem. The authoritative documents — vendor service manuals with illustrated parts catalogues — are the only place carrier part numbers and official compatibility statements exist, and they are frequently not reachable: some are behind client-side rendering our tooling cannot execute, and some vendors simply do not publish carrier part numbers at all in the manuals they make public. Meanwhile every aftermarket seller publishes a long, confident compatibility list.

Rather than pick one and pretend, we label both. A vendor fact is something stated in a manufacturer's own service or parts document, and we link that document. A seller claim comes from aftermarket listings' compatibility information — genuinely useful, frequently correct, and not a specification. Where the two disagree, the vendor document wins and we show the disagreement rather than quietly dropping the loser.

Where neither exists, the page says so: part number unverified — match by generation and bay size. That is less satisfying than a confident number, and it is a great deal better than a wrong one. A carrier part number that is correct for one chassis generation and incorrect for the next is a real cost to a real person, and the forums are full of numbers repeated until they sound official.

The same discipline runs through the controller pages. That a Broadcom 9300-8i is a host bus adapter is a vendor fact, published by Broadcom. That a used LSI 9211-8i on a marketplace has been flashed to IT mode is a seller claim, however plausible. Those two statements look similar and are not, and the badges on those pages keep them apart.

Start from the machine

Which parts you need follows from which server you have or are buying — the bay count and form factor decide the carriers, and the generation decides which carrier fits. Our used server buyer's guides cover ten of the most-traded models with their documented bay configurations, and each links through to the carrier generation and controller advice that applies to it.

For the drives themselves, a SAS backplane will take SATA drives as well as SAS, which is the fact that makes filling an enterprise chassis affordable. If the array is destined for ZFS, check the recording technology before buying — no parity level rescues an array built on shingled drives.