Pick a machine, a backplane configuration, drives and a memory target. The calculator adds the carriers automatically — one per drive — prices every line from our live catalogue, and gives you the total as two numbers: an exact parts sum and a chassis figure that is either a live listing or a dated estimate band.
Prices updated
| Part | Qty | Each | Total | |
|---|---|---|---|---|
| HP 4TB CMR · New | 8 | $56 | $448 | Buy |
| Drive carriers (sold in 5-packs) | 8 | $7 | $54 | Buy |
| 0P2R3R DELL PERC HBA330 12G Mini Mono SAS/SATA RAID Controll · New | 1 | $20 | $20 | Buy |
| A-Tech 64GB RDIMM (for 64 GB) | 1 | $516 | $516 | Buy |
Both halves are live prices. Excludes processors (which arrive fitted and which we do not price), rails and cables.
Nothing here is complicated, but several of the steps are ones people skip when doing it in their head, and the skipped ones are what make a cheap server turn out not to be cheap.
Drives are the cheapest in-stock listing matching the carrier size your chosen backplane uses, multiplied by how many bays you are filling. The condition filter is there because recertified enterprise drives are the normal supply for this kind of build and frequently the right buy — but they should be compared as themselves rather than blended in, so you can restrict the list either way.
Carriers are added automatically at one per drive, priced at the cheapest per-unit figure for that machine's generation. That distinction matters: carriers sell in 2, 4 and 10-packs, so the cheapest sticker price is frequently not the cheapest carrier. This is the line most people leave out of a mental budget entirely, and on a twelve-bay machine it is a meaningful sum.
Memory divides your target by the capacity of the cheapest module per gigabyte that our compatibility data says fits the platform, rounds up, and multiplies. Two of our ten models carry no verified memory profile — the R720 is DDR3 and we stock none, and we hold no Gen9-specific HPE profile — so those show no memory line rather than borrowing another machine's data.
The HBA is optional and defaults to on, because most people arriving here are building something that manages disks itself. When enabled it adds the cheapest card that is a host bus adapter by design rather than one flashed to behave like one — no firmware step, no seller claim to verify. Our IT mode guide explains why that distinction is worth paying attention to.
Usable capacity applies the RAID level to the drive count: single parity costs one drive, dual parity two, mirroring half the array. Cost per usable terabyte then divides the realistic total by that figure — so it inherits the chassis range where one exists, which is why it is sometimes shown as a range too.
For eight of the ten machines we hold verified Amazon listings and price the chassis live like any other part. For the other two we do not, and rather than leaving a gap or inventing a number we publish a dated estimate range based on the used market, clearly labelled as an estimate.
The reason those two differ is not that they are rare — it is that their market runs mostly through eBay and specialist refurbishers, which we do not price programmatically. Our where-to-buy guide covers those channels and what to expect from each.
The temptation is to take the midpoint of the band and print one number. We do not, because that number would be part measurement and part guess with no way for you to tell which is which — and it is precisely the number someone would quote back at us later. A range that is honest about its own uncertainty is more useful than a point estimate that hides it.
Take the configuration this tool opens on for an R730xd: the twelve-bay large-format chassis, twelve drives, carriers for each, an IT-mode card and a memory target. The parts line sums exactly, because every entry is a listing with a Buy button beside it. The chassis line shows a live figure where we have one.
What the exercise usually reveals is that the drives dominate — often by more than the chassis and everything else combined. That is the correct outcome and it is worth internalising, because it reframes the whole purchase: agonising over fifty dollars on the chassis while filling it with twelve drives is optimising the wrong line. It is also why the cost-per-usable-terabyte figure is the one to compare between configurations rather than the total.
The second thing it reveals is the carrier line, which is invisible in most people's planning and is real money on a twelve-bay machine. If a listing includes carriers, that is worth paying a premium for, and it is why sellers advertise “12x Trays” in a title.
Processors, because we do not track their prices and would have to invent a figure. Rails, because rail kits are chassis-generation and rack-depth specific and a wrong one is a bulky return. Cables, because what a controller needs depends on what your backplane presents — SFF-8643 on 12Gb/s-era hardware, SFF-8087 on 6Gb/s-era, and they are not interchangeable. Each of those is a question to put to a seller rather than a number we can supply honestly.
You will also find no performance figures anywhere in this tool. How fast an array feels, how many virtual machines a host runs, how many streams a media server sustains — all depend on your workload and configuration, and a number attached to a model rather than a machine is guesswork dressed as data.
If you want a configuration chosen for you rather than assembled yourself, the build guides cover four complete machines with the reasoning behind each choice. If you are still picking a model, the buyer's guides and comparisons come first.
For the array itself, the RAID planner goes deeper on usable capacity and rebuild considerations than the summary figure here, and the CMR list covers why recording technology matters for a parity array. When you are ready to buy, the channel guide and arrival checklist close the loop.
Because only part of it is a live price. Drives, carriers, memory and controllers are listings you can click through and buy, so they sum exactly. The chassis is either a verified Amazon listing or a dated estimate of the used market — for two of our ten models we hold no live listing, because those machines trade mostly through eBay and refurbishers we do not price. Adding a band's midpoint to a live sum would produce one confident number that is part measurement and part guess.
We do not track CPU prices, so any figure we printed would be invented. In practice used servers arrive with processors fitted, which is why the chassis price is for a configured machine rather than a bare board — read the listing to see which are in it. If you plan to upgrade later, price that separately.
Usable capacity comes from the drive capacity, the number of drives and the RAID level: single parity costs one drive, dual parity two, mirroring half the array. That figure is then divided into the realistic total including the chassis. Because the chassis is a range on some models, the cost per usable terabyte is a range too — it is derived from the same honest arithmetic rather than smoothed into a single number.
Because the configuration determines the carrier size, and carrier size determines which drives physically fit. A 3.5-inch chassis takes large-format drives; a 2.5-inch chassis does not, and no adapter makes a large drive smaller. This is the single specification you cannot change after purchase, which is why the calculator makes you choose it before anything else.
Yes — one carrier per drive, because that is how it works. Empty bays keep their blanks rather than sitting open, since the cooling design assumes the airflow path stays closed. The carrier price used is the cheapest per-unit figure in our catalogue for that machine's generation, which is frequently a multi-pack; per-unit is the honest basis for comparison rather than pack price.
Then our catalogue currently has no matching listing, and the tool says so rather than substituting something that does not fit or quietly dropping the line. That is a gap in what we track rather than a statement about the hardware. Stock changes; the table refills itself when it does.