Hard Drives

SAS vs SATA Server Hard Drives

SAS (Serial Attached SCSI) drives are the enterprise standard for server storage. SAS provides dual-port connectivity for redundancy. SAS hard drives connect at up to 12 Gb/s, and the drive and controller, not the server generation, set the link speed.

• SAS 15K RPM — Highest performance spinning drives. 2.5-inch and 3.5-inch. For transactional databases, OLTP, and latency-sensitive workloads where SSDs are not required.
• SAS 10K RPM — Balanced performance and capacity. 2.5-inch. For general-purpose server storage, virtual machine datastores, and mixed workloads.
• SAS 7.2K RPM (Nearline) — Bulk capacity in 3.5-inch form factor. For backup targets, file servers, archival, and cold storage tiers.

SATA drives are lower cost but single-port only (no dual-port failover). SATA HDDs at 6 Gb/s are suitable for development environments, non-critical storage, and cost-sensitive deployments where SAS reliability is not required.

2.5-inch vs 3.5-inch Form Factor

2.5-inch SFF drives fit more bays per server (up to 24 in a 2U chassis). Available in 10K and 15K RPM for performance workloads. Maximum capacity is lower per drive than 3.5-inch.

3.5-inch LFF drives provide maximum per-drive capacity. Used for bulk storage, nearline, backup, and archival. Fewer bays per server (typically 4-12 in rack servers).

Your server chassis determines which form factor you need — 2.5-inch and 3.5-inch drive bays are not interchangeable.

How to Choose the Right Server Hard Drive

1. Check your server's drive bay size — 2.5-inch or 3.5-inch
2. Match the interface — SAS or SATA (verify RAID controller compatibility)
3. Select RPM based on workload — 15K for IOPS, 10K for balanced, 7.2K for capacity
4. Contact Enterasource for bulk pricing on multi-drive configurations

Frequently Asked Questions

What is the difference between SAS and SATA server hard drives?

SAS (Serial Attached SCSI) drives offer dual-port connectivity for failover, and 10K and 15K RPM SAS models deliver higher performance through faster spindle speeds. SAS hard drives run at up to 12 Gb/s, and the drive and controller, not the server generation, set the link speed. SATA drives are single-port, run at 6 Gb/s, and cost less per gigabyte. SAS is the standard for production server workloads. SATA is appropriate for development, lab, and non-critical storage where dual-port redundancy is not required.

Can I use 2.5-inch drives in a 3.5-inch drive bay?

Yes, with a 2.5-inch to 3.5-inch drive adapter (also called a drive sled converter or hybrid tray). Some Dell PowerEdge and HPE ProLiant servers ship with hybrid drive trays that accept both form factors natively. Check your server's drive tray type before ordering — a standard 3.5-inch tray requires an adapter bracket to hold a 2.5-inch drive securely. You cannot use a 3.5-inch drive in a 2.5-inch bay.

What RPM speed do I need for my server workload?

15K RPM SAS drives deliver the highest IOPS from spinning media and are used for transactional databases and latency-sensitive applications. 10K RPM SAS drives provide a balance of performance and capacity for general-purpose workloads, virtual machine datastores, and mixed read/write environments. 7.2K RPM nearline SAS or SATA drives prioritize capacity over speed and are used for backup targets, file servers, archival, and cold storage tiers. For workloads requiring maximum performance, enterprise SSDs outperform all spinning drives.

Looking for solid-state storage? Browse enterprise SSDs for NVMe, SAS, and SATA options. Need a complete storage build? Browse server configurations with pre-configured RAID arrays.