Optimus® Product Family of SAS SSDs

SAS SSD: Comprehensive Technical Analysis of Optimus Series

In the field of enterprise level storage, balancing performance, durability, data integrity, and cost has always been a challenge faced by IT managers and OEM manufacturers. The Optimus series 6Gb/s SAS solid-state drives launched by SanDisk (now a subsidiary of Western Digital) provide highly competitive solutions for data centers, storage arrays, and SAN environments with its innovative Guardian Technology platform and multi-level product line for mixed read/write and write intensive applications. This article will provide a comprehensive and in-depth technical analysis of the Optimus series from the aspects of product positioning, core technology, performance parameters, durability classification, power protection, and physical specifications.

Product series and positioning

The Optimus series consists of three sub series: Optimus, Optimus Ultra, and Optimus Ultra+, each targeting enterprise application scenarios with different write intensities.

Optimus (Hybrid): Suitable for mixed read-write workloads such as online transaction processing (OLTP) databases, financial transactions, e-commerce, data warehouses, infrastructure, email/messaging, virtual desktops, and collaboration. Supports 10 to 25 full disk random writes per day.

Optimus Ultra (write intensive): Suitable for write intensive applications such as data warehousing, high-performance computing, oil and gas, life sciences, aerospace, engineering design, media editing, analysis, and database logging. Supports 25 to 35 full disk writes per day.

Optimus Ultra+: Designed for the highest durability requirements, supporting 50 to 55 full disk writes per day, suitable for extreme logging and high-frequency data collection scenarios.

All models come with a five-year warranty, demonstrating SanDisk's commitment to enterprise level reliability.

List of Core Features

Interface: 6Gb/s SAS, supports dual port and wide port, and can achieve up to 1 GB/s continuous read performance.

Capacity range:

Optimus：200 GB、400 GB、800 GB、1.6 TB

Optimus Ultra：150 GB、300 GB、600 GB、1.2 TB

Optimus Ultra+：100 GB、200 GB、400 GB、800 GB

Flash type: Commercial grade MLC (Multi Layer Cell) NAND Flash, with Guardian technology achieving a lifespan far beyond native durability.

Data reliability: The unrecoverable error rate (BER) is below 10 ^ 17 bits, and the MTBF reaches 2.5 million hours.

Security: AES 256 bit hardware encryption, compliant with TCG Enterprise specifications.

Data Protection: The three core technologies of FlashGuard, DataGuard, and EverGuard cover the extension of flash life, data path protection, and power outage protection.

Deep analysis of Guardian Technology platform

The core competitive force of the Optimus series comes from SanDisk's independently developed Guardian Technology platform, which includes three key technologies:

1. FlashGuard technology: significantly improves MLC flash durability

The native write life of commercial grade MLC flash memory is usually less than one full disk write per day. FlashGuard technology enhances it to a maximum of 50 full disk writes per day through two mechanisms:

Aggregated Flash Management: treats all flash components within an SSD as a unified system, performs global wear leveling and write optimization, and avoids excessive local wear.

Advanced Signal Processing: Dynamically adjust flash read/write parameters (such as reference voltage and programming step size) throughout the entire lifecycle of SSD, compensate for the aging characteristics of flash memory units, and significantly extend their effective service life.

In addition, FlashGuard also integrates proprietary Enhanced Error Correction Code (ECC) technology, further reducing unrecoverable error rates. It is the combination of these technologies that enables MLC flash memory to handle mixed use and even write intensive enterprise loads.

2. DataGuard technology: comprehensive data integrity protection

DataGuard technology ensures that user data is not damaged from two levels:

Full Data Path Protection: Within the SSD, every data path from the host interface to the flash array is checksum protected to prevent silent errors during data transmission.

F. R.A.M.E. (Flexible Redundant Storage Unit Array): This is a unique page/block level data recovery feature. Even in the event of catastrophic failures at the flash page or block level (such as bad blocks), F.R.A.M.E. can still recover user data through redundancy mechanisms, similar to RAID but integrated within SSDs.

3. EverGuard technology: power-off data protection

Unexpected power outages are a common cause of SSD data loss in enterprises. EverGuard technology adopts a third-generation backup power circuit design, using highly reliable discrete capacitors to provide sufficient hold time in the event of a host power outage, allowing SSDs to flush cached data to non-volatile areas of flash memory, thereby avoiding data damage or loss.

Detailed explanation of performance indicators

The Optimus series offers consistent random read and write performance across the entire range (related to capacity, typical high-capacity models):

Random read/write IOPS: up to 100000 reads/45000 writes (based on 4KB transfer, tested by Iometer 2008)

Continuous read/write bandwidth: 500 MB/s read/500 MB/s write (based on 128KB transfer). When using SAS Wide Port, the sustained read performance can reach 1 GB/s, making it suitable for streaming applications that require high throughput.

The actual performance may vary depending on drive capacity, host devices, operating systems, and application loads, but this series is at the leading level among enterprise SAS SSDs.

Durability Classification and DWPD

Durability is measured by "Drive Writes Per Day" (DWPD) and distinguishes between random workloads and sequential workloads:

Series random DWPD order DWPD warranty period

Optimus 10 25 5 years

Optimus Ultra 25 35 5 years

Optimus Ultra+50 55 5 years

This means that Optimus Ultra+can withstand 50 full disk random writes per day during the five-year warranty period, with a total write volume of 91250 times the astonishing original capacity, making it ideal for high-frequency transaction logs, real-time data collection, and other scenarios.

Security features: AES-256 and TCG Enterprise

The Optimus series supports AES 256 bit hardware encryption across the entire range, complying with the Trusted Computing Group's (TCG) enterprise level security standards. This enables SSDs to encrypt/decrypt stored data in real-time without affecting performance, and supports secure key management and encryption erasure (instantaneous data destruction through key replacement). For industries such as finance, government, and healthcare that have strict requirements for data security, this feature is crucial.

Power supply and power consumption

Working voltage: 5 V (-5%/+10%)

Typical active power consumption: 7 W (applicable to all models, regardless of capacity)

Low power design facilitates high-density deployment in storage arrays without excessively increasing heat dissipation burden.

Environmental and reliability specifications

Impact: 1000 g (half sine wave, 0.5 ms, 3 impacts along X/Y/Z axis, each direction)

Vibration: 2.17 g rms (7~800 Hz)

Working temperature: 0 ° C to 70 ° C (internal temperature)

Storage temperature: -40 ° C to 90 ° C

Humidity: 5% to 95%, non condensing

Altitude: up to 5486.4 meters (18000 feet)

These parameters indicate that the Optimus series is suitable for standard enterprise data center environments, including some non temperature controlled remote sites. For extreme environments such as military and aerospace, reinforcement grade products may be required.

Mechanical dimensions

The Optimus series adopts a standard 2.5-inch appearance and is suitable for hot swappable racks for enterprise level servers and storage arrays:

Length: 100.20 mm

Width: 69.85 mm

Height: 9.5 mm (applicable to Optimus Ultra+with capacity ≤ 800GB and some models) or 15 mm (applicable to 1.6TB Optimus, 1.2TB Optimus Ultra, and 800GB Optimus Ultra+)

When selecting, it is necessary to confirm whether the equipment bracket supports a height of 9.5 mm or 15 mm.

Sector format and compatibility

Supports multiple sector sizes: 512 bytes, 520 bytes, 528 bytes. This enables the Optimus series to be compatible with traditional servers (512 byte sectors) as well as certain specialized storage systems that require additional checksum bytes (such as network devices, telecommunications equipment, etc.).

Model and ordering information

The following are some typical ordering models (see data manual for a complete list):

Optimus series (mixed use):

200GB：SDLKAE6M-200G-5CA1

400GB：SDLKAD6M-400G-5CA1

800GB：SDLKAC6M-800G-5CA1

1.6TB：SDLLAC6M-016T-5CA1

Optimus Ultra (write intensive):

150GB：SDLKAEGW-150G-5CA1

300GB：SDLKADGW-300G-5CA1

600GB：SDLKACGW-600G-5CA1

1.2TB：SDLLACGW-012T-5CA1

Optimus Ultra+(Extreme Write Dense):

100GB：SDLKAE9W-100G-5CA1

200GB：SDLKAE9W-200G-5CA1

400GB：SDLKAD9W-400G-5CA1

800GB：SDLLAC9W-800G-5CA1

Suggested application scenarios

Virtual Desktop Infrastructure (VDI): The Optimus series can handle boot storms and random I/O peaks while providing reasonable costs.

Online Transaction Processing (OLTP): Requires low latency and high IOPS, and the Optimus series 100K/45K IOPS is sufficient to meet the needs of most banking and e-commerce systems.

High Performance Computing (HPC): Optimus Ultra/Ultra+can withstand a large number of write checkpoints and intermediate result storage.

Video editing and media processing: 1 GB/s continuous read performance in wide port mode, suitable for multi stream high-definition video playback.

Database log: Ultra+50 full disk writes per day, ensuring long-term log writes without slowing down.

Competition and Positioning Summary

In the SAS SSD market, the Optimus series competes with products such as Intel DC S3700/S3710, Samsung PM1633a, Toshiba PX04, etc. Its differentiation advantage lies in:

By utilizing FlashGuard technology, MLC flash memory achieves extremely high durability (up to 50 DWPD), approaching the write life of SLC flash memory at a much lower cost.

The complete data protection suite (data path, FRAME, power outage protection) enhances enterprise level reliability.

Clear layering of three sub series facilitates customers to choose based on actual write strength, avoiding over configuration or premature wear and tear.

Future prospects and precautions

With the popularity of NVMe SSDs in enterprise storage, SAS interfaces will still hold a place in terms of compatibility and dual port high availability. SanDisk/Western Digital subsequently launched series such as Infinity and CloudSpeed, but Optimus, as a classic product line, still plays a role in many deployed systems.

Please note that the data in this article is based on preliminary specifications from 2013, and actual commercially available products may have been updated. The capacity is marked as 1 GB=10 ^ 9 bytes, and the available capacity for users is slightly lower. Performance testing is based on an internal testing environment, and actual usage may vary.