Dell PERC H965i Tri-Mode RAID Controller: NVMe RAID Explained
The PERC H965i is Dell’s tri-mode RAID controller for 16th generation PowerEdge servers, and it is the first PERC that treats NVMe drives as array members rather than passing them through. This covers what changed and what it means for drive choices.
What is the Dell PERC H965i?
A PERC 12 series internal RAID controller for PowerEdge 16th generation servers (R660, R760, R6615, R7615 and siblings). It is tri-mode, meaning it handles SAS, SATA and NVMe drives through the same controller, and it can build RAID arrays across NVMe drives.
That last point is the change. Earlier PERC generations passed NVMe drives directly to the system; the H965i brings them under hardware RAID. Our PERC H730P guide covers the earlier generation for comparison.
What does tri-mode actually mean?
One controller, three drive interfaces, one set of bays.
A tri-mode controller connected to a tri-mode backplane presents each bay as SAS, SATA or NVMe depending on what is inserted. That is why 16th generation servers can mix drive types across their front bays in ways earlier generations could not.
The compatibility consequence: NVMe drives for tri-mode bays should be U.3. U.2 drives are not guaranteed to work in a tri-mode backplane. Our U.2 vs U.3 guide covers which direction the compatibility runs.
Can the H965i RAID NVMe drives?
Yes, and that is its main reason to exist.
Earlier PERCs could not; NVMe drives bypassed them entirely and redundancy had to come from software. The H965i builds hardware RAID across NVMe drives, which matters for organisations that want controller-managed redundancy on flash without a software layer.
Two honest points. Hardware RAID on NVMe adds latency compared with drives connected directly, since every operation passes through the controller. For workloads that need raw NVMe performance, direct attachment with software redundancy may still be faster. And the controller’s own throughput becomes the ceiling for a large NVMe array, where the drives together could exceed it.
Cache and battery
Same rule as every PERC: check the cache backup.
The H965i has write cache with battery or capacitor backup. If that backup fails, the controller drops to write-through and write performance collapses with no error reported. On a new-generation controller this is unlikely but not impossible, and it is the first thing to check on any PERC-equipped machine that feels slow. Our controller guide covers this.
Drive compatibility with the H965i
Three rules.
Dell-coded drives are the safe choice. PERC controllers validate firmware, and a non-coded drive may be flagged, may not report predictive failure, or may be refused during a rebuild. Our OEM guide covers this.
U.3 for NVMe, per above.
16th generation carriers. Dell carriers are generation-specific, and 16th generation may differ from 14th and 15th. Confirm before buying bare drives. Our kits guide covers why Dell kits remove the guesswork.
H965i vs H755 vs H965e
Three related controllers.
H755 is the 15th generation PERC. It handles SAS and SATA in hardware RAID; NVMe support is more limited. Not tri-mode in the same sense.
H965i is the 16th generation internal tri-mode controller, per this guide.
H965e is the external version, for connecting JBODs and external enclosures. Our JBOD guide covers what that involves.
They do not cross generations. An H965i fits 16th generation servers only.
Frequently asked questions
What servers use the PERC H965i?
Dell PowerEdge 16th generation servers such as the R660, R760, R6615 and R7615. It does not fit earlier generations.
Does the H965i support NVMe RAID?
Yes. It is the first PERC generation to build hardware RAID across NVMe drives rather than passing them through. Hardware RAID on NVMe adds some latency compared with direct attachment.
What is a tri-mode RAID controller?
A controller that handles SAS, SATA and NVMe drives through the same controller and backplane, presenting each bay as whichever type is inserted. NVMe drives for tri-mode bays should be U.3.
Can I use U.2 drives with the H965i?
Not guaranteed. Tri-mode backplanes are designed for U.3 drives. Some accept U.2 in NVMe mode; others do not. Buy U.3 unless Dell explicitly lists your U.2 drive as supported.
What is the difference between H965i and H965e?
The i is internal, for the server’s own bays. The e is external, for JBODs and external enclosures. Same generation, different role.
Why is my R760 slow with no errors?
Check the PERC cache backup. If it has failed, the controller drops to write-through and write performance collapses with nothing reported as a fault.
Dell PERC 12
PERC H965i Tri-Mode RAID Controller for PowerEdge 16G
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