Controller

The right controllers for your servers, workstations and storage systems

Controllers are critical to the storage performance and reliability of IT systems, including the management of storage devices. Various models are available for the different transfer standards SATA, SAS and NVMe, with the characteristics and features required for each application. In addition, remote controllers allow remote access to server systems, for example, not only to simplify the administration of complex IT infrastructures, but also to intervene quickly in the event of problems at remote locations. This makes remote administration an important tool for server management. Remote controllers enable specific fault diagnosis or firmware updates even in the event of serious failures, thanks to access via a web interface or special management software that is independent of the operating system.

However, when it comes to choosing the right controllers to expand existing server solutions or as replacement parts, it is essential to note that systems from different manufacturers often only support specific controllers, depending on the model and generation. For example, HPE ProLiant servers offer compatibility with Smart Array controllers for storage management and iLO (integrated lights-out) management modules for remote administration. Dell PowerEdge systems support PERC (PowerEdge RAID Controller) and iDRAC (integrated Dell Remote Access Controller) remote management adapters, which are similar in function and purpose. Depending on the model, a PCIe (PCI Express) slot on the motherboard or riser can often be used to install the controller cards. However, there are also proprietary slots, such as AROC (Adaptive RAID On Chip), which can exclusively be used for solutions designed specifically for the system.

SATA controllers - A solid option for low-cost storage solutions

The SATA (Serial Advanced Technology Attachment) interface is an older but widely used standard for connecting cost-effective SATA hard drives. Due to the relatively low transfer speed of a maximum of 6 Gbit/s compared to newer interfaces and the limited management options, SATA systems are often a budget-oriented solution for applications that focus on affordable capacity and simple storage management. The SATA controller handles communication between the host and the storage devices, managing drive configuration and data transfer. Depending on the storage capacity and access speed required, SATA controllers support the use of both traditional HDDs (hard disk drive) and fast SSDs (solid state drive). The high compatibility of the SATA standard means that even older servers can be flexibly upgraded to meet increasing storage requirements. As almost all mainboards now have integrated SATA ports, optional controller cards for this interface are becoming less important.

SAS controllers for scalable and reliable storage systems

Controllers using the newer and more capable SAS interface (Serial Attached SCSI) offer increased storage performance through the higher transfer rates of compatible SAS hard drives, while also providing excellent scalability through advanced drive management options. SAS systems are often used in scenarios where high transfer rates and reliability are required, such as large databases and virtualised environments. SAS controllers also support both HDD and SSD drives and often meet the needs of today's data centres and fast-growing enterprise IT infrastructures with features such as error detection and the capability to create complex storage domains with many hard drives.

To use numerous drives for high storage capacities, the controller's SAS ports can be extended, for example by using additional SAS expanders to connect more storage media and backplane boards. In addition, some controllers have a HBA mode (Host Bus Adapter) for the utilisation of external storage devices. This allows servers to connect to existing storage environments and access the stored data.

To increase data transfer, SAS controllers also often support cache modules of varying capacities that are used as buffer memory. These memory modules provide fast access speeds, ensuring low latency when reading and writing data. The cache can also protect against data loss in the event of a power failure. For this purpose, compatible controllers are equipped with BBUs (Battery Backup Unit), which act as a buffer and provide power to the controller for a short time via the battery module. This allows outstanding write operations to be completed before the system shuts down in the event of a power failure.

NVMe Controllers - Achieve the best storage performance with modern SSDs

As the most advanced and capable standard, NVMe (Non-Volatile Memory Express) controllers enable the highest transfer speeds and lowest latency by supporting high performance NVMe SSD drives. The NVMe protocol uses the server's PCI Express (PCIe) interface, enabling high-bandwidth communication between the host system and the flash memory. This makes NVMe controllers ideal for applications with demanding storage performance requirements such as databases, real-time analytics and virtualisation. To create customised and expandable storage solutions, Tri-Mode controllers offer a high degree of flexibility by supporting SATA and SAS standards in addition to NVMe. Compatible systems detect which hard drive types are installed and manage them using the appropriate transfer protocol. Depending on the model and generation of a server, NVMe connections can also often be expanded using appropriate adapters and extenders.

RAID Controllers - Reliability and performance improvement through redundancy

A key function of storage controllers is managing the connected disks in a RAID (Redundant Array of Independent Disks) configuration and handling the distribution of data across the drives. By combining a server's hard disks into one logical drive, the risk of data loss can be reduced and read/write performance can be increased. The chosen RAID level determines the type of drive organisation and offers different features and benefits. When selecting controllers for server systems, it is therefore important to ensure that the required RAID levels are supported for the intended configuration to meet individual requirements for performance, data integrity and storage capacity.

Features and benefits of common RAID levels

• RAID 0: Data is striped across multiple drives to increase read and write speed, so it is typically referred to as striping. However, it lacks redundancy, which means that the failure of a single drive can result in a complete loss of data. This RAID level is suitable for media editing, for example, where high performance is more important than data security.
• RAID 1: All data is duplicated by mirroring, resulting in a high level of fail-safe reliability as a drive failure will not result in data loss. However, there is no increase in performance. RAID 1 is therefore suitable for applications where the safety of critical and sensitive data is a top priority.
• RAID 10: This is a combination of RAID 1 and RAID 0, with mirroring for increased data protection and striping for improved performance. RAID 10 is more expensive as half of the drives are used for data mirroring. This configuration is suitable for demanding applications such as databases that require both high performance and data protection.
• RAID 5: By distributing data and parity information across multiple drives, RAID 5 allows one drive to fail without data loss, as the data can be recovered. The combination of performance, data security and storage capacity is often ideal for file servers.
• RAID 50: This combination provides redundancy through multiple RAID 5 arrays and stripes the data to improve performance. However, this results in a slightly higher management complexity for the drives. This RAID level can be used for video streaming servers, for example.
• RAID 6: Compared to RAID 5, RAID 6 uses additional parity information, which means that a total of two hard drives can fail without data loss. The resulting increase in data protection often meets the high demands of business applications for processing sensitive data.
• RAID 60: As with RAID 50, redundancy and increased performance are combined by using multiple RAID 6 arrays and striping technology. This provides similar benefits for large databases with increased data security and performance, but at a higher administration effort.

Large selection of refurbished controllers at affordable prices - ServerShop24

To adapt the storage solutions of your IT infrastructure to existing and future increasing requirements or for the efficient management and administration of your server systems, powerful controllers are indispensable components. In our online shop you will find a wide range of used RAID and remote controllers with an excellent price-performance ratio for various systems from well-known manufacturers such as HPE, Dell, Lenovo and Fujitsu. Even if you need special spare parts for older servers, which are often no longer available as new parts, it is worth looking for carefully checked used controllers from our stock.
Since 2010, we have been your reliable partner for professionally refurbished used servers, workstations, storage systems and network equipment. With fast shipping of your order from our large warehouse, we offer short delivery times so that your systems can be upgraded and repairs can be carried out quickly. If you have any questions about the products or configuration options, our friendly and experienced support team will assist you. Contact us by phone, email, live chat or via our ticket system - we will take care of your request!