I’ve had my DGX Spark running for a while now. I have connected a wireless dongle to one of the USB ports for the keyboard and mouse. No problem here.
However now is time to add other external peripherals. The DGX Spark has 3 USB-C 3.2 Gen 2x2 which support 20Gbps transfer speeds. Unfortunately, I am not finding and dock or hub that supports Gen 2x2. The other device I’m looking for would be a 4 slots or more enclosure for M.2 NVMe SSDs.
Has anyone found either type of device I’m looking for and tried it with the DGX Spark?
You should be able to use any USB hub that supports USB Type-C
I have two drives connected via USB-C (20 Gbps each) configured in a RAID 0 setup.
The enclosure supports up to 40 Gbps, and the RAID operates at full performance when the link is negotiated correctly.
The issue occurs after unclean system restarts (system updates, VRAM-related lockups, or other freezes). In these cases, when the DGX Spark boots again, the drives are enumerated at 480 Mbps, indicating an incorrect USB link negotiation.
The operating system properly detects the devices, the RAID assembles successfully, and no filesystem-level errors are reported. However, performance is severely limited due to the link falling back to USB 2.0 speeds.
The only way to restore the correct speed (20 Gbps) is to physically disconnect and reconnect the drives, at which point the USB link renegotiates correctly.
I have implemented an automation that detects when the drives are negotiated at 480 Mbps and proactively unmounts the RAID. This allows me to simply disconnect and reconnect the drives to recover performance, but manual intervention is still required.
The following actions have already been attempted without success:
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Unmounting and remounting the volumes
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Reinitializing the RAID
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Logical USB device resets
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Other operating system–level solutions
The issue appears to be related to USB link renegotiation after forced or unclean reboots, rather than the drives, the enclosure, or the RAID configuration itself.
I am looking for a way to force a software-level USB disconnection and re-enumeration, equivalent to a physical unplug/replug, in order to eliminate the need for manual intervention.
I have bought a OWC Express 4M2. I’ve put 4 4TB SSDs in it and used a ZFS file system with raidz and it works well. I see a little less than 12TB available in my file system.
It does mount automatically on reboot.
It does not seem to go faster than 10Gbps though. Nevertheless, it does the job for what I need.