SSD Problems: Not Detected, Write Slowdown, Sudden Disappearance
An undetected M.2 drive is more often a shared-lane conflict than a failure. Check the board's exclusivity table first.
M.2 SSD not detected
M.2 slots often share lanes with SATA ports or PCIe slots. Using one can disable the other.
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- Read the exclusivity table in the manual — e.g. 'M.2_2 disables SATA5/6'.→ Moving the drive to another M.2 slot often resolves it.
- Confirm whether the drive is NVMe or SATA. The M.2 form factor is shared but slots may support only one.
- M.2 seats at an angle then screws down. An unsecured drive does not make contact.
- Check BIOS. Visible in BIOS but not in Windows usually means it just needs initialising in Disk Management.
Writes slow down partway through large transfers
This is not a fault. Most SSDs write into a fast cache region; once exhausted, speed drops to the native rate.
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- Check free space. Less free space means a smaller fast region. Keeping 20–30% free softens the drop.
- Check whether the drive is DRAM-less. Those degrade more under sustained writes.
- Check temperature. M.2 drives throttle above roughly 70°C. Confirm a heatsink is fitted.Tool: CrystalDiskInfo or similar
Drive disappears or the system freezes
Drives vanishing mid-use usually trace to heat, power settings, or firmware. Protect your data first.
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- Back up first. Continued use after this symptom risks a permanent loss on the next occurrence.
- Check SMART values: reallocated sectors and total bytes written.Tool: CrystalDiskInfo
- Check for firmware updates. Vendors have fixed disappearance bugs in firmware.
- Disable PCI Express link state power management in the power plan and retest.