Solid State Drives (SSDs)

SAS vs SATA vs NVMe Server SSDs

NVMe SSDs connect directly via PCIe for the lowest latency and highest throughput. NVMe Gen 4 delivers up to 7 GB/s sequential read — 10x faster than SAS SSDs. Used for database storage, caching tiers, and latency-sensitive applications. Requires NVMe-capable drive bays or universal slots.

SAS SSDs provide dual-port connectivity for hardware RAID and failover. 12 Gb/s SAS (or 24 Gb/s SAS-4 on 16th Gen) is the enterprise standard when hardware RAID is required. Compatible with Dell PERC and HPE Smart Array controllers.

SATA SSDs are the lowest-cost SSD option at 6 Gb/s. Single-port only. Suitable for boot drives, read-heavy workloads, and cost-sensitive deployments where SAS dual-port redundancy is not required.

Read-Intensive vs Mixed-Use vs Write-Intensive

Enterprise SSDs are rated by endurance class — the number of drive writes per day (DWPD) the drive is warranted for:

• Read-Intensive (RI) — Less than 1 DWPD. Lowest cost per GB. For read-heavy workloads: web serving, media streaming, boot drives, read replicas.
• Mixed-Use (MU) — 1-3 DWPD. Balanced read/write. For virtual machine datastores, general database, email servers.
• Write-Intensive (WI) — 3-10+ DWPD. Highest endurance. For write-heavy databases, OLTP, logging, caching tiers.

Choosing the right endurance class affects both cost and drive lifespan. Over-specifying wastes budget; under-specifying risks premature wear.

How to Choose the Right Server SSD

1. Check your server's interface support — NVMe requires NVMe-capable bays; SAS/SATA work with standard bays
2. Match endurance to workload — RI for reads, MU for balanced, WI for writes
3. Select form factor — 2.5-inch (standard) or E3.S (16th Gen R660 only)
4. Contact Enterasource for volume pricing on multi-drive configurations

Frequently Asked Questions

What is the difference between read-intensive, mixed-use, and write-intensive SSDs?

Enterprise SSDs are rated by DWPD (drive writes per day) — the amount of write endurance warranted over the drive's service life. Read-intensive drives (under 1 DWPD) cost the least per gigabyte and are designed for workloads that are 90%+ reads, such as web serving, media delivery, and database read replicas. Mixed-use drives (1-3 DWPD) handle balanced read/write patterns for VM datastores and general databases. Write-intensive drives (3-10+ DWPD) withstand the heaviest write loads for OLTP, transaction logging, and caching tiers. Selecting the correct endurance class optimizes both cost and drive lifespan.

NVMe vs SAS SSD — which is better for my server?

NVMe SSDs connect directly to the PCIe bus and deliver up to 7 GB/s sequential read on Gen 4, with significantly lower latency than SAS. NVMe is the best choice for latency-sensitive databases, caching, and any workload that saturates SAS bandwidth. SAS SSDs provide dual-port redundancy and are managed by hardware RAID controllers (Dell PERC, HPE Smart Array), making them the standard for environments that require hardware RAID for data protection. If your server has NVMe-capable bays and your workload benefits from maximum throughput, choose NVMe. If you need hardware RAID or your server only has SAS bays, choose SAS SSDs.

What SSD endurance class do I need for virtualization?

For most VMware vSphere and Hyper-V virtualization workloads, mixed-use (MU) SSDs rated at 1-3 DWPD are the standard. VM datastore I/O patterns are typically a 60/40 to 70/30 read/write mix, which aligns with mixed-use endurance. Read-intensive drives can work for lightly-written VM environments (VDI read replicas, web server pools), but risk premature wear under sustained VM provisioning or vMotion activity. Write-intensive drives are only necessary for dedicated database VMs with heavy transaction logging.

Need spinning storage for capacity workloads? Browse enterprise server hard drives. Looking for a complete storage build? Configure a server with pre-built RAID arrays.