PERC stands for PowerEdge RAID Controller, Dell's own name for the hardware RAID cards it builds for PowerEdge servers. When a controller fails, the server usually loses access to its array. When a cache battery wears out, write performance tends to drop with no obvious error on screen. This range of refurbished Dell RAID controllers covers both situations. It runs from the cache-less PERC H330 to the H975i NVMe controller, together with the batteries, boot cards and NVMe cabling that sit around them.
Getting the right part is mostly a matching exercise. You need to check the server generation, the slot the controller occupies and the drives behind it. You also need to decide whether you want hardware RAID at all. If you would like the background first, our guide to understanding RAID controllers covers the fundamentals before you pick a part number.
Dell storage controllers at a glance
- Controllers
- PERC cards for Dell PowerEdge servers. The range starts with the H330, a SAS3 controller with no onboard cache, and goes up to the H975i, an NVMe Gen5 controller supplied with its supercapacitor.
- Form factors
- Mini Mono controllers fit a dedicated storage slot on the motherboard and leave the PCIe risers free. Adapter and low-profile (LP) cards use a standard PCIe slot instead.
- Cache batteries
- For the H710, H730, H730P and H830, choose either the H730P Mini Mono battery with bracket (H132V) or a bare battery without bracket. There is also a separate H740P battery and bracket (NWJ48) for the H740 and H740P.
- Boot storage
- BOSS-S1, a low-profile card for two SATA M.2 drives in 2280 or 22110 length.
- NVMe enablement
- The 14G PCIe NVMe enablement card (CDC7W) is a low-profile x8 card with two U.2 ports. R640 10SFF NVMe expansion cables are listed by bay group, including the R640 NVMe cable for bays 2 to 5 (TXC4H) and versions for bays 6 to 9.
- Identification
- Listings carry the Dell part number, for example 9JXVW, H132V, NWJ48, 61F54 or CDC7W. Matching it against the part already in your server is the quickest way to confirm a like-for-like swap.
Matching a PERC controller to your PowerEdge server
Server generation. Dell develops its PERC range alongside each PowerEdge generation. A controller from a 13th-generation PowerEdge R630 or R730 is therefore not automatically the right card for a 14th-generation R640 or R740, even where the names look alike. Parts in this range labelled 14G are intended for 14th-generation systems. When in doubt, use the part number on the card or battery you are replacing as your guide.
Slot and form factor. A Mini Mono controller such as the PERC H730P Mini sits in its own slot on the motherboard. That keeps the PCIe slots free for network or GPU cards. Adapter and low-profile cards go in a standard PCIe slot. The two formats are not interchangeable, and the battery mounting can differ between them, so confirm which style your server uses before ordering.
Drive interface. SAS and SATA drives on a standard backplane run through a SAS controller such as the H330. NVMe drives connect over PCIe instead. Adding them means fitting either an NVMe-capable controller like the H975i or a PCIe path from the drive bays, which is the job of the NVMe enablement card and bay cables on supported 14th-generation chassis.
Cache and its protection. A cached RAID controller holds writes in memory before committing them to disk, which is what keeps parity RAID usable under load. That cache needs a battery or supercapacitor to survive a power cut. When the battery degrades, a PERC card will normally drop to write-through mode to protect your data, and writes slow down noticeably. On an older server, a replacement battery is often the cheapest performance fix available.
Hardware RAID or direct disk access. ZFS, Ceph, Storage Spaces Direct and similar software-defined storage want to see raw disks rather than a RAID volume. Many PERC controllers offer a non-RAID or HBA mode for this. Support varies by model and firmware, so check the specific Dell controller card before planning a build around it.
Typical deployments
Virtualisation hosts
VMware, Hyper-V and Proxmox hosts running guests on local disks generate small random writes from many machines at once. Choose a cached controller in the H730P or H740P class with a healthy battery. Use RAID 10 rather than RAID 5 for the VM datastore. Keep the hypervisor on a separate boot device so a datastore rebuild never touches it.
Databases and transaction logs
SQL Server, PostgreSQL and similar engines care more about write latency than raw throughput. Put transaction logs on a mirrored or RAID 10 volume behind protected write cache, and size the data volume for random reads. On a platform that supports it, the Dell H975i NVMe controller moves the array onto PCIe-attached drives rather than SAS.
Boot and hypervisor installs
Keeping the operating system apart from the data array makes reinstalls and rebuilds far simpler. The BOSS-S1 takes two SATA M.2 drives, typically mirrored, on a low-profile card, which leaves every front bay free for data. If the hypervisor writes logs locally, choose endurance-rated M.2 drives.
Software-defined storage
TrueNAS, ZFS, Ceph and Storage Spaces Direct need direct access to each disk for health monitoring and their own redundancy. Here a simple SAS3 controller without cache, run in non-RAID mode where the model supports it, is usually a better fit than a large cached card, and it costs less. Avoid layering software RAID on top of a hardware RAID volume.
NVMe upgrades in the R640
A 10-bay PowerEdge R640 can take NVMe drives in some of its front bays once the correct cabling and enablement card are fitted. Cables are sold by bay group, so match them to the bays you plan to populate. If you are still choosing a platform, our refurbished PowerEdge R640 range is a sensible starting point for 1U storage-heavy builds.
Backup targets and bulk storage
Large LFF arrays running RAID 6 put the heaviest load on parity calculation, and this is where controller cache earns its keep. Spinning disks rarely saturate a SAS link, so put cache and battery health ahead of interface speed. Plan for longer rebuilds on high-capacity drives, and keep a spare battery on the shelf.
Why buy Dell RAID controllers from Compuwyze
- Controllers, batteries and cables carry a 12-month return-to-base warranty. Our warranty information page sets out the details.
- Order simple items such as controllers and batteries before 2pm and we aim to ship them the same day.
- UK delivery is normally next working day once shipped, and it is free on orders over £50.
- International orders go via FedEx economy or priority services and usually arrive in 2 to 5 days.
- Returns are accepted within 30 days. The customer pays the cost of return shipping.
- If you need a complete machine rather than a part, servers built through our server configurator carry a 3-year return-to-base warranty, and we aim to ship them within 2 business days.
Dell PERC controllers: common questions
What is a Dell PERC controller?
PERC is short for PowerEdge RAID Controller, Dell's brand for the hardware RAID cards fitted to PowerEdge servers. The controller manages the physical drives and builds them into mirrored or parity arrays. It also handles parity calculation and caching, then presents the result to the operating system as ordinary volumes. Supported RAID levels and features vary from model to model.
Can I replace a RAID controller without losing data?
Usually, yes. PERC controllers store the array configuration on the disks themselves. A replacement of the same model will normally detect it as a foreign configuration that you can import. Take a backup first, keep the drives in their original bays, and never initialise or clear the configuration on the new card. Moving to a different controller family is less predictable, so treat it as a migration rather than a swap.
How do I know the controller battery needs replacing?
The controller log and the server's management tools will usually flag a degraded or failed battery. Write performance often drops at the same time, because the card switches to write-through mode. Batteries are a wear item, so replacing one on an older server is routine. Choose the bracket version if the original bracket is damaged or missing.
What is the difference between the PERC H730P Mini and the adapter version?
They belong to the same controller family but use different physical formats. The Mini Mono version fits the dedicated storage controller slot on the motherboard, while the adapter is a PCIe card. They cannot be swapped for one another in the same server position. Check what is fitted now, or the original build for your service tag, before ordering.
Are these controllers suitable for PowerVault storage?
That depends on the setup. Some PowerVault enclosures connect to a host through a controller fitted in the PowerEdge server. PowerVault arrays with their own built-in controllers use dedicated controller modules instead. Search by the Dell part number of the component you are replacing, and contact us if a listing does not make the match clear.
Where do I get drivers and firmware for a Dell RAID controller?
Dell publishes drivers, firmware and management utilities for PERC controllers on its support site. Look them up by your server's service tag rather than by card model alone, so you get versions validated for that system. Update the controller firmware before you put a replacement card into production.