SAS vs SATA: The Cheapest Hard Drives on Amazon Are Ones You Probably Cannot Plug In
Someone on r/DataHoarder put the whole problem in one sentence:
“I’m looking to build a budget nas and it looks like some of the best value is in SAS drives but I don’t know how to find a cheap system to put them in since they don’t work with sata”
I want to start with an admission, because this article is partly about my own site.
I run a price comparison site whose flagship page is called cheapest hard drives per terabyte. Twenty of the twenty-five cheapest listings on it right now are SAS drives, which most people reading this cannot plug into anything they own. Sorting by my north-star metric funnels a visitor almost exclusively into hardware they cannot use, and that is a real problem with the page rather than a quirk of the market.
So here is the honest version, measured from the live Amazon.com catalogue I track on 10 August 2026, 2,326 hard drive listings at 2 TB and above.
The rule that resolves most of these threads
Before anything else, the one line that nobody puts in a buying guide, from the most useful comment in the whole harvest:
“A SAS HBA can run SATA disks and SAS disks at the same time, while a SATA controller will not run SAS disks. For a plain bunch of disks, the main gotchas are the cable or backplane, keeping the HBA in IT/JBOD mode, and checking any used SAS drives are not formatted with 520-byte sectors”
- u/norri-matt, r/DataHoarder
A SAS controller runs SATA drives. A SATA controller never runs SAS drives. The compatibility only runs one way, and every confused thread on this subject is someone discovering that direction the expensive way.
If you already have a SAS host bus adapter, SAS drives are simply another option on the menu and you can mix them with SATA on the same card. If you do not, a SAS drive is a drive plus a card plus a cable, and the card and cable are the part nobody prices.
How much of the cheap end is SAS
| Cheapest N by $/TB | SAS count | Share |
|---|---|---|
| 10 | 6 | 60% |
| 25 | 20 | 80% |
| 50 | 36 | 72% |
| 100 | 63 | 63% |
Catalogue mix overall: SATA 1,200, USB 612, SAS 506.
So SAS is 22% of the drives I track and 80% of the cheapest twenty-five. That is not a small skew.
And it is not because SAS is cheaper
This is the part I expected to go the other way. Median price per terabyte, today:
| Interface | Listings | Median $/TB |
|---|---|---|
| SATA | 1,200 | $47.50 |
| SAS | 506 | $48.17 |
SAS is fractionally dearer as a class. And cutting it by capacity, which is the comparison that actually matters, it is equal or dearer in every single band:
| Capacity | SATA median | SAS median | SAS vs SATA |
|---|---|---|---|
| 2 to 4 TB | $55.33 | $59.37 | +7% |
| 6 to 8 TB | $49.60 | $47.94 | -3% |
| 10 to 12 TB | $40.00 | $45.56 | +14% |
| 14 to 16 TB | $39.29 | $40.00 | +2% |
| 18 to 24 TB | $35.92 | $37.05 | +3% |
There is no SAS discount. SAS owns the bottom of an ascending price-per-TB sort for a completely different reason: the enterprise gear that gets decommissioned and dumped onto the second-hand market in bulk is old, small and SAS. It is a sampling effect, not a pricing one.
You can see it in the list itself. Of the twenty-five cheapest listings today, twenty-four are 4 TB or smaller, and the survivors are decade-old OEM parts with names like EQUALLOGIC 3TB NL SAS, HP 695507-003 and Pulled 529FG ST4000NM0023.
There is an irony in that I should own. My own deals pages tell people not to buy 4 TB drives because the price per terabyte is bad. The page that ranks purely on price per terabyte is 24/25 drives of 4 TB or smaller.
The double trap, which is the actual finding
Here is the thing I did not expect and have not seen written anywhere.
Everyone frames this as “cheap SAS drives are a trap because you need an adapter”. True, but incomplete. I priced the real decision: the cheapest SAS listing against the cheapest SATA listing at the same capacity, and asked what going SAS actually saves you per drive.
| Capacity | Cheapest SAS | Cheapest SATA | Saving per drive |
|---|---|---|---|
| 2 TB | $37.39 | $34.00 | -$3.39 |
| 3 TB | $43.95 | $25.00 | -$18.95 |
| 4 TB | $69.95 | $73.00 | +$3.05 |
| 6 TB | $109.99 | $148.00 | +$38.01 |
| 8 TB | $169.00 | $209.00 | +$40.00 |
| 12 TB | $259.95 | $299.00 | +$39.05 |
| 14 TB | $339.00 | $329.00 | -$10.00 |
| 16 TB | $399.99 | $409.00 | +$9.01 |
| 18 TB | $570.00 | $459.99 | -$110.01 |
| 20 TB | $741.00 | $579.99 | -$161.01 |
Read the top and the bottom of that table together.
The rows that lure you in are exactly the rows where SAS saves you nothing. Twenty-four of the twenty-five cheapest listings on my site are 4 TB or smaller. At 2 TB and 3 TB the cheapest SATA drive is actually cheaper than the cheapest SAS one. At 4 TB, going SAS saves you three dollars and five cents a drive, so you would need fourteen of them to repay even a cheap adapter.
Meanwhile SAS genuinely does win at 6, 8 and 12 TB, by $38 to $40 a drive, and those rows sit far enough down the page that nobody sorting by price per terabyte ever scrolls to them.
So the cheap end is a trap twice over. You cannot plug those drives in, and they are not even the SAS drives worth buying.
(A caveat I owe you on the 2 to 4 TB rows: at those capacities both columns are ancient OEM pulls, so I am comparing one pile of decade-old parts against another. The comparison is fair but neither side is a drive I would recommend. From 6 TB up the comparison is between things you might actually want.)
The break-even, honestly
I cannot price your adapter. I track hard drives, and there are zero host bus adapters, breakout cables or controller cards in my catalogue, so anything I told you about their price would be invented. The community names LSI 9207-8i, 9300-16i and Dell PERC H310 cards constantly, and I have deliberately not looked up prices I would then be quoting second-hand.
So here is the arithmetic with your number in it. If an adapter and cable cost you H, and going SAS saves S per drive, you break even at H ÷ S drives.
| Capacity | Saving per drive | Break-even if H = $40 | if H = $60 | if H = $100 |
|---|---|---|---|---|
| 4 TB | $3.05 | 14 drives | 20 drives | 33 drives |
| 6 TB | $38.01 | 2 drives | 2 drives | 3 drives |
| 8 TB | $40.00 | 1 drive | 2 drives | 3 drives |
| 12 TB | $39.05 | 2 drives | 2 drives | 3 drives |
| 16 TB | $9.01 | 5 drives | 7 drives | 12 drives |
| 2, 3, 10, 14, 18, 20 TB | negative | never | never | never |
That is the whole decision in one table. At 6 to 12 TB, an adapter pays for itself in one to three drives, which is most real builds. At 4 TB you would need to fill a rack. At the capacities where SATA is cheaper, no drive count ever gets you there.
And it compounds: an adapter is a one-off, so if you are filling eight bays with 8 TB SAS drives you are $320 ahead on the drives against maybe $60 for the card.
Concretely, at the capacity with the best case today: an 8 TB SAS enterprise pull is $169.00 at $21.12/TB against the cheapest 8 TB SATA at $209.00, $26.12/TB. At 6 TB there is a SAS drive at $109.99 with a stated 60 month warranty, $18.33/TB, which is the best value on this whole page if you have a card.
Go the other way at the top end, though. At 18 TB the cheapest SATA drive is $459.99 against $570.00 for SAS, and at 20 TB SATA is $579.99 against $741.00. Buying SAS at those capacities costs you money and adds a card.
The gotchas, in the order they bite
Assume you have decided SAS is worth it. These are the things the threads say people hit, roughly in the order they hit them.
1. The card has to be in IT or JBOD mode. A lot of cheap second-hand cards are RAID controllers that present a hardware array rather than raw disks, which is not what you want if the filesystem is doing the redundancy. Flashing to IT mode is well documented and it is also the step where people brick a card. Buy one already flashed if that is an option.
2. Cables and backplanes. The connector standards are a small alphabet (SFF-8087, SFF-8643 and friends) and the wrong one is useless. If you are going straight from card to drives you need a breakout cable, one card port to four drives. If you have a backplane you need a different cable. Work this out before ordering, not after.
3. 520-byte sectors. This is the sharpest one and the least known. Enterprise arrays often format drives at 520 or 528 bytes per sector to carry extra integrity data. Pull one of those drives, plug it into a normal system, and it will not present usably until you reformat it to 512. It is fixable and there are well-trodden tools for it, but it is a step that exists only for used enterprise SAS and it arrives after your money has gone.
4. Noise and power. Most of these are 7,200 RPM datacenter parts designed to live in a room nobody sits in. A stack of them idles hotter and louder than the consumer drives they are replacing. If the box lives in an office or a living room, factor that in.
5. They are old. Not a defect, just a fact worth pricing. The community’s own attitude is cheerfully fatalistic:
“I say do it at 21€ ea. They’re so old, that they’ll either crap out fairly quickly or last forever.”
- u/djtodd242, r/DataHoarder
“the ones I’ve bought have been from ebay so it’s luck of the draw”
- u/RealityOk9823, same thread
Everything in what to check before you buy a used drive applies here and applies harder, because the warranty column on old enterprise pulls is usually blank.
Who should buy SAS, and who should not
Buy SAS if you already have a host bus adapter, or you are filling four or more bays at 6 to 12 TB, or you are building something that was always going to need a card anyway. In those cases it is straightforwardly good value and the community is right to like it. The reassuring version, from someone talking a beginner down:
“SAS is the bigger faster brother of SATA and does some amazing things. But if the drive is just going into your PC case you just need the HBA and the right cables.”
- u/Valanog, r/DataHoarder
Do not buy SAS if you are putting one or two drives in a desktop, if you are shopping at 2 to 4 TB, if you are buying at 18 TB or above, or if the appeal is purely that it looked cheapest on a sorted list. In every one of those cases you are paying for an adapter to access a discount that is not there.
And if you are not sure, the test is simple: does anything you own already have a SAS port? If the answer is no and you are buying fewer than four drives, buy SATA and stop thinking about it.
What I am doing about my own page
It would be a bit rich to write all this and leave the page as it is.
The data I need is already there. Every listing I track carries an interface field and it is well populated: SATA 1,200, USB 612, SAS 506, with only four unknown. So a SAS badge on every listing card, and a filter that lets you exclude SAS in one click, are both buildable without inventing anything. Both are on the development backlog and this is the fourth time the problem has been written down, which is three times more than it should have taken.
While checking the numbers for this article I also found a row I do not trust. Position 7 on the cheapest list is Toshiba Hard Drive MBF2600RC, listed as 2 TB, SATA, 3.5 inch. That model number follows the naming convention for a 600 GB 2.5 inch SAS part, which would make it wrong on capacity, interface and form factor at once. I have not opened the manufacturer datasheet, so I am flagging it rather than declaring it, and it has gone into the moderation queue to be checked properly. The last time I audited my own catalogue I found a motorcycle footpeg clamp ranked as the cheapest hard drive on the site, so I have stopped assuming the top of that list is clean.
Bottom line
As of 10 August 2026, on Amazon.com:
- A SAS controller runs SATA drives. A SATA controller never runs SAS drives. That one direction explains almost every confused thread on the subject.
- 80% of the 25 cheapest drives per TB on my site are SAS, and 24 of 25 are 4 TB or smaller.
- There is no SAS discount. Median SAS is $48.17/TB against SATA at $47.50, and SAS is equal or dearer in every capacity band.
- The cheap end is a double trap. At 2 to 4 TB, where all the temptation is, SAS saves you nothing or costs you more.
- SAS genuinely wins at 6, 8 and 12 TB, by $38 to $40 a drive, which repays an adapter in one to three drives.
- SATA wins clearly at 18 and 20 TB, by $110 and $161 a drive.
- Check for 520-byte sectors before you assume a used enterprise SAS drive will just work.
For live prices, cheapest HDD per TB ranks everything I track, and until that page has a SAS filter, read the interface before you read the price. Best enterprise HDDs covers the datacenter drives this article keeps running into, and refurbished and used drives covers what to check before paying for any of them.
Figures in this article were measured from the live Amazon.com listings I track on 10 August 2026, across 2,326 hard drive listings at 2 TB and above. Host bus adapter and cable prices are deliberately absent because I do not track those products and will not quote a price I have not measured. Reddit quotes are from public threads, linked at each quote. HDDHunt earns a commission on purchases made through links on this site, at no extra cost to you. See the affiliate disclosure.