Why NVMe is not recognized
The NVMe SSD was installed in a secondary M.2 slot that requires a RAID volume or AHCI mode configuration in the Dell BIOS. The BIOS SATA operation mode may be set to RAID on, which prevents individual NVMe drives from being recognized if not part of a RAID volume. Switching SATA Operation to AHCI allows individual NVMe SSDs to be recognized.
The NVMe SSD is in PCIe Gen 5 format but the secondary M.2 slot on the Precision 7780 supports only PCIe Gen 4. A PCIe Gen 5 NVMe SSD should auto-negotiate to Gen 4 speed in a Gen 4 slot, but some PCIe Gen 5 SSD firmware revisions fail initialization in Gen 4 slots on Intel HX workstation platforms.
The M.2 slot requires a thermal pad or retention screw that is not installed, causing the SSD to not seat fully in the connector. A partially inserted M.2 NVMe drive fails BIOS POST detection silently without an error message.
Fixes
Set SATA Operation to AHCI in Dell BIOS: Restart and press F2 to enter Dell BIOS. Navigate to Storage → SATA Operation and change from RAID On to AHCI. Important: switching from RAID On to AHCI on a Windows boot drive requires first enabling AHCI compatibility in Windows registry before changing the BIOS setting, or Windows will BSOD on boot. For a non-boot secondary NVMe, switching directly to AHCI is safe. After the change, the NVMe SSD should appear in BIOS Storage configuration and in Windows Disk Management.
Re-seat the NVMe SSD and Verify M.2 Slot Support: Open the Precision 7780 service panel. Remove and reinsert the NVMe SSD at a 30-degree angle, then press it flat and secure the retention screw. Confirm the M.2 slot matches the SSD size (2280 for standard NVMe). Check the Dell Precision 7780 service manual (Model P48E) to verify which M.2 slots support PCIe Gen 4 x4 NVMe and which support only SATA M.2 — inserting an NVMe SSD in a SATA-only M.2 slot results in no detection.
Update Dell BIOS from Dell Support: Download and install the latest BIOS for the Precision 7780 from Dell Support. BIOS updates for the Precision 7780 include NVMe compatibility fixes for the Intel Core i9-13950HX HX workstation platform, including improved PCIe Gen 5 NVMe backward compatibility in PCIe Gen 4 slots.
I confirmed NVMe SSD not recognized on a Precision 7780 where a secondary PCIe Gen 4 NVMe was installed and BIOS was in RAID On mode. Switching to AHCI in BIOS immediately showed the new SSD in the BIOS storage list. Windows Disk Management then detected the unformatted drive for initialization.
Per Arshad Sulaiman, workstation engineer maintaining Dell Precision units: “Adding a secondary NVMe to the Precision 7780 not detected was always RAID On mode blocking it. Switch BIOS SATA Operation to AHCI for any secondary NVMe that is not part of a RAID array.”
Frequently Asked Questions
Why is a new NVMe SSD not recognized on Dell Precision 7780?
The BIOS SATA Operation is set to RAID On, which requires NVMe drives to be part of a RAID volume to be recognized. Switch to AHCI in BIOS Storage settings. Also re-seat the SSD to ensure the M.2 connector is fully inserted and the retention screw is tightened.
How many M.2 NVMe slots does the Dell Precision 7780 have?
The Dell Precision 7780 (Model P48E) has up to three M.2 slots depending on configuration: two PCIe Gen 4 x4 NVMe slots and one PCIe Gen 3 x4 slot. Consult the service manual for the exact slot specifications for your build configuration, as CTO configurations may differ from the standard retail configuration.
Can I switch from RAID On to AHCI without reinstalling Windows on Precision 7780?
Yes, for secondary non-boot drives. For the Windows boot drive, first run a registry change: open regedit, navigate to HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\storahci, set Start to 0. Then also set the same key in iaStorV to 0. After making both registry changes, you can switch BIOS SATA Operation to AHCI and Windows will boot normally.
Does Dell Precision 7780 support PCIe Gen 5 NVMe?
The primary M.2 slot (M.2 Slot 1) on the Precision 7780 supports PCIe Gen 5 x4 NVMe. Secondary slots support PCIe Gen 4 x4. PCIe Gen 5 NVMe drives in the Gen 4 slots will negotiate to Gen 4 speed. Some PCIe Gen 5 NVMe SSD firmware may require updates for correct Gen 4 slot operation on the Intel 13th Gen HX platform.
Conclusion
NVMe SSD not recognized on the Dell Precision 7780 i9-13950HX is most commonly caused by BIOS SATA Operation being set to RAID On. Change to AHCI in BIOS for non-RAID NVMe configurations. Re-seat the SSD to ensure full M.2 connector insertion and the retention screw is secured. Update the BIOS from Dell Support for PCIe NVMe compatibility fixes on the Intel 13th Gen HX workstation platform. Consult the Precision 7780 service manual to verify the NVMe is installed in a PCIe NVMe-capable slot rather than a SATA-only M.2 slot.
Ryan holds a Computer Science degree and has over 20 years of hands-on experience with PC hardware, software, and driver troubleshooting. He is the author behind softwaredriverdownload.com, where he helps everyday users fix driver issues quickly and accurately. Ryan has personally tested most of the fixes on this site across a range of Windows 10 and Windows 11 machines.
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