SAS SSDs
SAS SSDs are solid state drives on the Serial Attached SCSI interface, so they install in SAS-capable drive bays and run on SAS RAID controllers and HBAs, the same as SAS hard drives. They come as 2.5-inch drives at 12Gb/s and 24G SAS, with older 6Gb/s models; check the listing for its endurance class and for any SED or FIPS encryption. Our lab tests each SAS SSD on receipt and again before shipping.
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EMC 118000634 Unity 7.68TB SAS SSD 2.5" 12Gbps RI Solid State Drive | MZ-ILS7T60Availability: Available by QuoteManufacturer: EMC Corporation Condition: Refurbished 1 Year WarrantyRequest PricingOut of stock - EMC 118000518 1.92TB SAS SSD 2.5" 12Gbps Solid State DriveAvailability: Available by QuoteManufacturer: EMC Corporation Condition: Refurbished 1 Year WarrantyRequest PricingOut of stock
- EMC 118001016-02-NEW 7.68TB TLC SAS 2.5" 12Gbps RI SED SSD | KPM6WRUG7T68Availability: Available by QuoteManufacturer: EMC Corporation Condition: New 1 Year WarrantyRequest PricingOut of stock
- EMC 118999819-01 1.6TB TLC SAS 2.5" 12Gb MU SSD | WUSTR6416BSS200 | EMC ONLYAvailability: Available by QuoteManufacturer: EMC Corporation Condition: Refurbished 1 Year WarrantyRequest PricingOut of stock
- HPE P09922-001 400GB MU SAS SFF 12G Solid State Drive | P09105-001Availability: Available by QuoteManufacturer: HPE Condition: Refurbished 1 Year WarrantyRequest PricingOut of stock
- Dell TP4W3 3.84TB TLC SAS 2.5" 12G RI Solid State Drive | Toshiba KPM5XRUG3T84Availability: Available by QuoteManufacturer: Dell Condition: Refurbished 1 Year WarrantyRequest PricingOut of stock
- NetApp X319A 7.68TB SAS 2.5" 12Gbps Solid State DriveAvailability: Available by QuoteManufacturer: NetApp Condition: Refurbished 1 Year WarrantyRequest PricingOut of stock
- IBM 01NN832 7.6TB SAS 2.5" 12Gbps Solid State DriveAvailability: Available by QuoteManufacturer: IBM Condition: Refurbished 1 Year WarrantyRequest PricingOut of stock
- IBM 02WF182 7.6TB SAS 2.5" 12Gbps Solid State DriveAvailability: Available by QuoteManufacturer: IBM Condition: Refurbished 1 Year WarrantyRequest PricingOut of stock
- Dell 4KPKF 3.84TB TLC SAS 2.5" 12Gbps RI SED Solid State Drive | XS3840SE70134Availability: Available by QuoteManufacturer: Dell Condition: Refurbished 1 Year WarrantyRequest PricingOut of stock
- Dell K74WN 960GB TLC SAS 2.5" 12Gbps RI Solid State Drive | Samsung MZ-ILT960CAvailability: Available by QuoteManufacturer: Dell Condition: Refurbished 1 Year WarrantyRequest PricingOut of stock
- IBM 01ML224 7.6TB SAS SSD 2.5" 12Gbps RI Solid State DriveAvailability: Available by QuoteManufacturer: IBM Condition: Refurbished 1 Year WarrantyRequest PricingOut of stock
When a SAS SSD is the right choice
Pick a SAS SSD when the server or array already runs SAS and needs flash in the same bays. SAS SSDs install in SAS backplanes, run behind the same PERC, Smart Array and HBA controllers as SAS hard drives, and keep SAS's second port: Seagate builds its 12Gb/s SAS SSDs with dual ports, and KIOXIA quotes up to 720,000 random 4 KiB reads per second for its 24G SAS read-intensive drives in dual-port mode.
SAS SSD vs NVMe vs SATA SSD
SAS SSDs fit servers that already have a SAS backplane and controller, NVMe fits NVMe-capable bays, and SATA fits the widest range of controllers; the sequential-read figures are examples from each maker's data sheet:
| Interface | Interface speed | Sequential read (data sheet example) | Ports | Best for |
|---|---|---|---|---|
| 24G SAS SSD | 22.5Gb/s per lane, backward compatible with 12Gb/s and 6Gb/s SAS | Up to 4,200 MB/s (KIOXIA, dual-port) | Dual-port | 24G controllers such as Dell's PERC 12 family |
| SAS SSD (12G) | 12Gb/s per port | Up to 2,200 MB/s (Seagate, dual-port) | Dual-port (HA capable) | RAID arrays, existing SAS backplanes, HA clusters |
| NVMe SSD | PCIe Gen 4 and Gen 5 | Up to 7,400 MB/s (Seagate, Gen 4) | Single- or dual-port, by model | Latency-critical apps, scratch/cache, all-flash |
| SATA SSD (6G) | 6Gb/s | Up to 550 MB/s (Samsung data-center SATA) | Single-port | Boot drives, secondary storage, cost-sensitive deployments |
Behind a 12Gb/s controller such as a PERC 11, a 24G SAS SSD links at the lower rate.
SAS SSD vs SAS hard drive
On the same 12Gb/s port, a SAS SSD moves data several times faster than the quickest SAS hard drive, and it skips the 2.0 ms average rotational wait a 15K drive pays on every random access. The hard drive keeps its place where capacity per bay matters more than speed; see SAS hard drives.
Endurance classes for SAS SSDs
SAS SSDs come in three endurance classes, and Seagate's 12Gb/s SAS line shows how each class pairs with its own capacity points:
| Class | Rated drive writes per day | Capacity points in Seagate's line | Workload |
|---|---|---|---|
| Read-intensive (Seagate: scaled endurance) | 1 | 960GB, 1.92TB, 3.84TB, 7.68TB, 15.36TB | Read-heavy work |
| Mixed use | 3 | 800GB, 1.6TB, 3.2TB, 6.4TB | Mixed reads and writes |
| Write-intensive | 10 | 400GB, 800GB, 1.6TB, 3.2TB | Write-heavy work |
That is why a 960GB and an 800GB drive are rarely the same class. The pattern follows over-provisioning, which Seagate describes as flash set aside from the user to raise endurance. Compare the capacity points on 960GB SSDs and 800GB SSDs.
What a SAS SSD needs in the server
A SAS SSD needs a SAS-capable drive bay and backplane plus a SAS HBA or SAS RAID controller because, per Seagate, a SAS drive will not work on a SATA-only controller. Build SAS SSDs into their own virtual disks, since PERC 11 does not allow SAS and SATA drives in the same one, and order drive carriers separately under hard drive caddies and trays. Controllers are on SAS HBAs and RAID controllers.
SAS SSD questions
- Is a SAS SSD faster than a SAS hard drive?
- Yes, by a wide margin. Seagate rates its dual-port 12Gb/s SAS SSDs at up to 2,200 MB/s sequential read, against 210 to 300 MB/s sustained for its 2.5-inch 15K SAS hard drives, and an SSD has no 2.0 ms rotational wait on random reads. Both use the same SAS bays and controllers, so a SAS SSD is a drop-in speed upgrade where the server already runs SAS.
- Can a SAS SSD go in a SATA-only server?
- No. A SAS SSD needs a SAS controller or SAS HBA and a SAS-capable backplane, and Seagate's support note rules out connecting a SAS drive to a SATA controller. The reverse works, since a SAS controller also runs SATA drives. In a SATA-only server, choose a SATA SSD, or add a SAS controller and the backplane support it requires.
- SAS SSD or NVMe: which should I choose?
- Choose by the bays you have. NVMe reads faster, up to 7,400 MB/s on Seagate's Gen 4 drives against 2,200 MB/s on its 12Gb/s SAS SSDs, but it needs NVMe-capable bays or a PCIe slot. A SAS SSD drops into existing SAS backplanes and controllers and keeps a second port. PERC 11 also keeps NVMe drives out of SAS and SATA virtual disks.
Comparing across the whole range? See all server SSDs, SATA SSDs, NVMe SSDs and U.2 NVMe SSDs, or read our explainers on SSD endurance classes and DWPD and TBW ratings; SAS vs SATA covers the interfaces.
