Best 8-Bay NAS: The Drive Math Before the Enclosure
Before comparing eight-bay enclosures, price the drives: eight NAS drives at $200 to $500 each is a $2,000 to $4,000 purchase against roughly $1,300 for the box. The UGREEN NASync DXP8800 Plus ($1,369.99) is the best eight-bay NAS for most builds. At eight members with large drives, SHR-2 or RAID 6 is mandatory, because a single-parity rebuild across eight 20 TB drives reads about 140 TB.
Start with the drives, because on an eight-bay build they are not an accessory, they are the purchase. Eight NAS drives at $200 to $500 each is $2,000 to $4,000 in one order, against roughly $1,300 for the enclosure they go into. The chassis is a quarter to a third of the spend. Two consequences follow immediately: double parity is mandatory at this member count, and the enclosure comparison matters far less than it appears to.
Three picks below, then the drive arithmetic, then the enclosure specifications that genuinely differ. Read the parity section before you order drives, because it changes how many terabytes you need to buy.
Best 8-bay NAS by what the array is for
Asustor Lockerstor 8 AS6508T (8-Bay, 10GbE)
An Atom C3538 server chip and two 10 gigabit ports built in, which is unusual at the bottom of the eight-bay range. No integrated graphics, so no hardware transcoding.
Best for: Bulk storage and backup on a network that already has 10GbE.
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UGREEN NAS DXP8800 Plus (8-Bay, Core i5-1235U)
A ten-core Core i5, four M.2 slots and dual 10GbE. On raw specification nothing else in the eight-bay class comes close at the price.
Best for: Large arrays that also run containers, virtual machines and Plex transcoding.
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Synology DS1825+ (8-Bay Diskless)
ECC memory, SHR-2, and the only ecosystem where mixed drive sizes count fully. You are paying for DSM and for the upgrade path, not for processing power.
Best for: Archives you intend to keep for a decade and grow one drive at a time.
Check pricePrices change often, confirm on Amazon. As an Amazon Associate we earn from qualifying purchases.
The drive math, before anything else
Eight bays is a different kind of purchase from four. At four bays the drives and the box are roughly comparable amounts of money. At eight the drives dominate completely, and unlike the box they get replaced on a rolling schedule for as long as you own the array.
| Drive choice | Per drive | 8 drives | Raw | Usable, SHR-2 or RAID 6 | Rebuild reads, single parity |
|---|---|---|---|---|---|
| Seagate IronWolf 8TB | $289.99 | $2,319.92 | 64 TB | 48 TB | 56 TB |
| WD Red Plus 8TB | $353.99 | $2,831.92 | 64 TB | 48 TB | 56 TB |
| WD Red Plus 12TB | $459.99 | $3,679.92 | 96 TB | 72 TB | 84 TB |
| IronWolf Pro 16TB | $579.99 | $4,639.92 | 128 TB | 96 TB | 112 TB |
| Seagate Exos 20TB | $799.99 | $6,399.92 | 160 TB | 120 TB | 140 TB |
| WD Red Pro 24TB | $1,059.99 | $8,479.92 | 192 TB | 144 TB | 168 TB |
Capacities are decimal TB as printed on the label. Your NAS reports each figure about 9.05 percent smaller because it counts in binary tebibytes, so 96 TB usable shows as 87.3 TiB. Rebuild reads is how much data the array must read off the seven surviving members to reconstruct one failed drive.
Why SHR-2 or RAID 6 is mandatory at eight members
Double parity means two drives of the array are given over to redundancy, so two members can fail without data loss. On eight bays that costs you a quarter of your raw capacity, and it is the correct trade for two independent reasons.
The first is member count. Rebuilding a failed drive under single parity means reading every sector of all seven survivors. Any one of them failing, or returning an unrecoverable read error at the wrong moment, ends the array. More members means more opportunities for that.
The second is rebuild duration. Look at the last column of the table above. A single-parity rebuild across eight 20 TB drives reads about 140 TB, and a 20 TB member resilvering at a realistic 80 to 150 MB per second takes roughly 37 to 70 hours. That is two to three days during which the array is unprotected and every remaining drive is being read end to end, on drives that are the same age and often from the same manufacturing batch.
Do not run single parity on eight large drives. Manufacturers rate NAS drives at one unrecoverable read error per 10^15 bits, and 140 TB of reads against that rating is a meaningful chance of hitting one. Treat that rating carefully: it is a warranty floor rather than a measurement, observed fleet rates are much better, and both ZFS and mdadm survive a single read error rather than aborting. Use it to rank layouts, not as a forecast. The conclusion is the same either way. Run SHR-2, RAID 6 or RAIDZ2.
Work your own drive set through the RAID capacity calculator, which shows usable capacity, parity overhead and rebuild read volume for every layout side by side, and see RAID 5 against RAID 6 for the full argument.
The eight-bay field, priced with drives included
Below is the wider eight-bay field with the two totals that matter: the chassis on its own, and the chassis plus eight drives at both ends of the sensible capacity range. The gap between the columns is the point of this page.
| Model | Processor | Integrated GPU | Network | ECC | M.2 | Box only | With 8 x 8TB | With 8 x 16TB |
|---|---|---|---|---|---|---|---|---|
| TERRAMASTER F8 SSD Plus | Core i3-N305, 8 core | Quick Sync | 1 x 10GbE | No | 2 | $674.99 | $2,995 | $5,315 |
| Asustor Lockerstor 8 AS6508T | Atom C3538, 4 core | None | 2 x 10GbE | Optional | 2 | $965.99 | $3,286 | $5,606 |
| QNAP TS-873A-8G | Ryzen V1500B, 4 core | None | 2 x 2.5GbE | Yes | 2 | $1,249.00 | $3,569 | $5,889 |
| Synology DS1825+ | Ryzen V1780B, 4 core | None | 4 x 2.5GbE | Yes | 2 | $1,369.75 | $3,690 | $6,010 |
| UGREEN NAS DXP8800 Plus | Core i5-1235U, 10 core | Quick Sync | 2 x 10GbE | No | 4 | $1,369.99 | $3,690 | $6,010 |
Drive totals use eight Seagate IronWolf 8TB at $289.99 and eight IronWolf Pro 16TB at $579.99, the same verified prices used on our NAS drive comparison. Box prices change often.
Notice how the spread narrows. The cheapest and most expensive chassis differ by around $695, which sounds decisive until you populate them, at which point the same two builds differ by less than a fifth of their total. Choose the enclosure on features you will actually use, not on price, because the price difference is noise against the drive bill.
Which enclosure specifications genuinely matter here
- Integrated graphics. The AMD Ryzen embedded parts, V1500B and V1780B, and the Atom C3538 all lack an integrated GPU entirely, so they cannot hardware transcode video. If Plex is on the workload list, that is disqualifying. See best NAS for Plex.
- ECC memory. More defensible at eight bays than anywhere else, because the arrays are large, long-lived and full of data you rarely re-read. A silently flipped bit in an archive is corruption you discover years later.
- Network ports. A large array can genuinely saturate gigabit, since one 7200 rpm drive alone sustains 150 to 260 MB per second against 1GbE's 113 MB per second ceiling. 2.5GbE reaches around 280 MB per second and 10GbE around 1,100 MB per second, but only if you own the switch. Check 2.5GbE against 10GbE first.
- Power and UPS sizing. Eight drives at 6 to 9 W idle is 48 to 72 W of spindles before the board, and spin-up draws more. A NAS this size wants a pure sine wave UPS. Size it with the UPS runtime calculator.
Who should not buy the Expert pick
The Synology DS1825+ at $1,369.75 is a strong archive machine: ECC, SHR-2 and the longest software track record in the category. Plenty of people should not buy it, and one group should not buy any of these boxes yet.
Two specific mismatches. If you want Plex transcoding, the DS1825+ runs a Ryzen embedded part with no integrated graphics, so every transcode falls to the cores. The UGREEN pick costs effectively the same and has Quick Sync. And if you are buying eight bays because you might fill them one day, the honest advice is to buy four bays with larger drives now: four 16 TB drives is $2,319.96 for 32 TB usable under double parity, against eight 8 TB drives at $2,319.92 for 48 TB usable but a $1,370 chassis on top.
Above all, do not let the enclosure eat the drive budget. An eight-bay box with four drives in it is a four-bay NAS that cost twice as much. If the total will not stretch to filling most of the bays with capacity you need, put that money into drives instead and buy a smaller chassis, or wait until the drive budget is genuinely there.
Related reading
- Best NAS hard drives for the $2,000 to $4,000 half of this purchase
- How to migrate to a bigger NAS if you are moving off a four-bay unit
- Drive failure probability calculator for the odds across eight drives over five years
- Usable capacity chart for precalculated figures at every bay count
- 3-2-1 backup rule guide because 96 TB of parity is still not a backup
Deciding on a specific model? We review the UGREEN NASync DXP8800 Plus review, Synology DS1825+ review and QNAP TS-873A-8G review in full.
Frequently asked questions
How much does an 8-bay NAS build really cost?
The enclosure is the small half. Eight-bay boxes run roughly $675 to $1,370, and eight NAS drives at $200 to $500 each is $2,000 to $4,000 on top. A realistic complete build with eight 8 TB drives is around $3,700, and with eight 16 TB drives around $6,000. Budget the chassis at a quarter to a third of what you will actually spend.
Do I need RAID 6 or SHR-2 on an eight-bay NAS?
Yes, treat double parity as mandatory at eight members with large drives. Two things stack against single parity here: with eight drives there are seven surviving members that must all read perfectly during a rebuild, and modern drive capacities make that rebuild take days rather than hours. RAID 6, RAIDZ2 and SHR-2 all keep protecting the array during the window when it is most exposed.
How long does an eight-drive array take to rebuild?
A 20 TB member resilvering at a realistic 80 to 150 MB per second takes roughly 37 to 70 hours, and longer while the array is also serving files. During that window the array reads every sector of all seven surviving drives, which for 20 TB members is about 140 TB of reads. That read volume, not the failure itself, is what makes single parity indefensible at this scale.
Is an eight-bay NAS better than two four-bay units?
One eight-bay chassis is more efficient with parity, because eight drives under double parity gives six drives of usable capacity while two separate four-bay arrays under double parity give four. It also draws less power and takes one power supply. Two separate units win on blast radius: a failed backplane or power supply takes out half your storage rather than all of it.
Should I fill all eight bays at once?
Fill enough bays for the capacity you need now plus a year of growth, and leave the rest empty if the budget is tight. Buying eight drives in one order also means eight drives from similar manufacturing runs aging identically, which clusters failures. Split the order across two retailers, and expand later rather than committing $4,000 to drives you will not use for two years.
Can an eight-bay NAS transcode for Plex?
Only if it has Intel integrated graphics. Several eight-bay units use AMD Ryzen embedded chips such as the V1500B and V1780B, or Atom server parts, none of which have an integrated GPU, so there is no Quick Sync engine to offload to. If the box needs to transcode, choose one built on an Intel Core or Core i3-N series chip and check for Quick Sync explicitly.
How we choose: we compare published manufacturer specifications, drive datasheets, published reliability statistics and verified owner reviews. We do not test hardware in person, and we are not tied to any NAS vendor. Capacity and power figures here are researched guidance, not a warranty. RAID protects against drive failure, not against deletion, ransomware, fire or theft, so keep verified backups regardless of what any calculator tells you.
Working out your own cost per usable terabyte? The Home Server Build Planner is the paid version of these pages: 8 printable worksheets you fill in with your own numbers, plus the full PDF, $29.