840993-B21 HPE 1.6TB SATA 6G RI LFF LPC SSD

Key technical attributes

Capacity and form factor

With a nominal usable capacity of 1.6TB, the 840993-B21 sits in the high-capacity side of HPE's read-intensive SATA LPc SSD family, providing a balance between raw storage density and cost per gigabyte when compared to higher-end NVMe or enterprise SLC/QLC tiers. Its 3.5-inch (large form factor) profile and LPc carrier make it compatible with server trays and sleds intended for LFF drives. 

Interface and throughput

The drive uses the SATA interface and conforms to SATA/600 (6Gb/s) electrical and protocol standards. Nominal sequential throughput tops out at the SATA lane's practical limits — vendors list the data transfer rate at approximately 600 MB/s — which makes the device suitable for sequential reads and moderate writes but optimized for small random read operations typical of many server workloads. 

Flash type and workload targeting

The 840993-B21 employs multi-level cell (MLC) NAND flash and is characterized as a Read-Intensive (RI) drive. MLC provides a middle ground between cost and endurance compared with SLC/ eMLC and higher-density flash types; in HPE's configuration this translates into firmware and wear-management tuned to favor read performance and predictable latency for read-dominant applications. For use-cases that perform many small reads (for example, virtual desktop infrastructure read caches, content distribution nodes, and metadata stores), an RI MLC SSD is often the most cost-effective option.

Random I/O performance

Published random I/O figures for the device indicate very healthy small-block read performance: manufacturers and distributors list 4KB random read IOPS on the order of ~75,000 IOPS and 4KB random write IOPS of roughly ~11,000 IOPS, figures that highlight the product's strength in read-heavy workloads where latency and request throughput matter more than raw sequential bandwidth. These numbers are representative vendor figures and will vary with controller firmware, queue depth and system integration. 

The a read-intensive 1.6TB SATA SSD

Cost-to-performance balance

Compared to high-end NVMe devices, SATA RI SSDs typically deliver lower cost per GB while still massively improving request latency and throughput when compared with spinning media. For environments where reads dominate (analytics nodes, web caches, content repositories), the 840993-B21 can be a way to accelerate application performance without the premium of NVMe storage tiers.

Predictable behavior in mixed environments

Because the drive is tuned for read-dominant workloads, system architects can rely on steady, repeatable read latency under realistic production loads. This predictability simplifies performance budgeting — you can consolidate more read-heavy virtual machines or containers onto fewer storage devices while retaining acceptable response times.

Density and rack-scale advantages

The 1.6TB density in a 3.5-inch carrier enables straightforward capacity planning for racks and enclosures that accept LFF devices. When compared with multiple smaller drives of lower capacity, a fewer-drive approach reduces points of failure and can simplify RAID/erasure coding layouts, provided you follow HPE best practices for redundancy and rebuild performance.

Compatibility and deployment considerations

Server compatibility

The HPE 840993-B21 is widely listed as compatible with ProLiant ML and DL family servers; vendors and resellers typically call out explicit model support for Gen10/Gen11 systems and earlier platforms that accept LFF SATA LPc SSDs. Confirm chassis compatibility and backplane support — most HPE server backplanes that support SATA LPc SSDs will handle this drive, but mixed carrier/backplane versions exist and should be validated during procurement. 

Firmware and firmware management

Enterprise SSDs rely on firmware tuned for endurance, garbage collection and thermal management. When deploying at scale, plan a firmware maintenance policy: check HPE's support channels or your server management stack (Integrated Lights Out — iLO — or HPE OneView) for recommended firmware revisions and update procedures. Firmware updates can improve stability, performance and compatibility but must be tested in staging prior to wide rollout.

Hot-swap and carrier form factor

The low profile carrier (LPc) and 3.5-inch format enable hot-swap capability in many HPE hot-plug enclosures — essential for enterprise operations that require drive replacement without server downtime. Ensure you use proper ESD handling and follow HPE replacement instructions for safe insertion and removal. 

Use cases and workload examples

Primary read cache for hybrid storage tiers

In hybrid architectures where NVMe or SSD layers front a tier of high-capacity HDDs, the 840993-B21 makes an excellent read cache. Its high random read IOPS and MLC reliability allow frequently accessed blocks to be served quickly while write-back or tiering policies move less-frequently read blocks to HDD layers.

Database index and query acceleration

Databases with read-heavy query profiles (OLAP indexes, reporting nodes, readonly replicas) benefit from the SSD's small-block random read performance. When used for database indexes, lookups and materialized views, the lower latency reduces query response times and increases concurrency. Properly configure database I/O queues and alignment to extract maximum value.

Virtual desktop and VDI persistent images

VDI read storms (when many desktops boot or perform I/O simultaneously) can be smoothed by placing golden images and persistent read structures onto fast read-optimized SSDs. The 1.6TB capacity allows consolidation of many images on a single drive or RAID set, lowering management complexity while improving user experience.

Performance tuning and best practices

Queue depth and workload characterization

SSD performance is highly sensitive to queue depth. For small random reads, deeper queues generally increase IOPS until the controller is saturated. In contrast, write performance and sustained throughput may require larger buffers or slower background garbage collection behaviors; for read-intensive drives like the 840993-B21, optimize the host I/O profile toward read concurrency where possible.

RAID configuration guidance

When using RAID, select levels and stripe sizes according to the workload: RAID5/6 improves capacity efficiency but can impact write performance due to parity calculations, while RAID10 provides better write latency at the expense of capacity. For primarily read workloads, RAID5 may be acceptable; for mixed or write-sensitive workloads, prefer RAID10. Always leave spare capacity for rebuild operations and test rebuild times since SSD rebuilds differ from HDD rebuild semantics.

Temperature and thermal throttling

Monitor drive temperature in dense enclosures. Enterprise SSDs include thermal guards that throttle performance under high heat to protect NAND. Plan airflow, fan policies and ambient temperature targets to avoid sustained throttling in heavy read scenarios.

Reliability, endurance and warranty

Endurance expectations

As an MLC Read-Intensive SSD, the 840993-B21 is optimized for workloads that issue many more reads than writes. This class of drive generally provides moderate endurance suitable for index and cache roles rather than heavy write logging. As always, calculate lifetime in drive-writes-per-day (DWPD) or total bytes written (TBW) relative to your workload to ensure the selected drive meets your retention and refresh cycles.

Part number and cross-references

When ordering, confirm the exact HPE part number (840993-B21) to avoid mismatches. Some resellers list internal or substitute part numbers for packaging (SUB PN/BULK listings), so always cross-check the SKU and physical carrier type to guarantee tray compatibility. 

Packaging considerations

Drives can be shipped in factory sealed bags, static shielding trays or OEM hot-swap carriers. Verify packaging to ensure drives arrive with the required sleds or adapters for immediate insertion into your server chassis; some aftermarket listings sell drives without carriers to reduce cost but this may introduce integration work.

Migration and retrofit advice

Replacing legacy HDDs

When migrating from HDDs to SSDs in existing systems, plan for changes in capacity planning, RAID rebuild behavior and thermal management. SSDs deliver far superior random I/O; however, they can expose CPU or memory bottlenecks previously masked by slower disk. Test representative workloads to validate the overall stack after migration.

Hybrid caching layers

The 840993-B21 is a natural fit for a read cache tier in hybrid storage arrays or software-defined storage solutions that allow policy-based tiering. Because it is tuned for reads, it accelerates cache hits with little added write amplification — an important consideration in tiered systems where writes may be redirected to persistent higher-end layers.

Lifecycle and refresh planning

Plan refresh cycles based on metric-driven thresholds (SMART warnings, TBW, performance drift, and firmware end-of-support announcements). Maintain a phased replacement schedule so that capacity and performance remain consistent across clusters during refresh windows.

Comparison with other HPE storage options

SATA RI vs eMLC / SLC enterprise drives

HPE's SATA RI MLC class sits below eMLC/SLC offerings in raw endurance and write performance but is much more cost competitive on a per-GB basis. For write-heavy database logging or high-frequency transactional systems, eMLC or NVMe enterprise drives are preferred; for read caches, cold-hot split tiers and content delivery nodes, RI MLC is frequently the best value.

SATA vs NVMe

NVMe drives exceed SATA in latency and parallelism, offering significantly higher IOPS and lower CPU overhead. However, NVMe typically costs more per GB and may require NVMe capable backplanes and host controllers. If your workload is bottlenecked by small random reads and you can afford higher tiers, NVMe is better; if you need density and cost control with good read performance, the 840993-B21 remains an attractive option.

Final procurement 

Before you buy

• Confirm server compatibility (ProLiant model and backplane support for LPc/LFF SATA drives).
• Decide between new and refurbished units and verify warranty length from the seller. 
• Validate firmware version and obtain vendor firmware update guidance for your server platform.
• Plan RAID/erasure coding strategy and leave spare capacity for rebuilds.

After delivery

• Verify physical carrier and mounting hardware, and install into appropriate trays.
• Monitor SMART attributes and integrate alerts into your monitoring system.
• Test performance under representative workloads before moving to production.