I am having power problems with my Allegro USB PCIe Card.
If you are experiencing issues with your Allegro USB PCIE card, try the following troubleshooting steps.
When you connect any USB peripheral to the device, is anything shown in About This Mac > System Report > Hardware > USB?
1) Regarding the issue: this may be that the USB devices are pulling more than 2A of power per device.
The Allegro cards include resettable fuses built into these cards’ ports that will trip when a connected device pulls more than 2A of power. Have you tried connecting one device to port 1, and another to port 4?
See our tech note here for more details, and how to reset these.
2) Also, we found that many hard drive and USB peripheral manufacturers will include a gen 1 low power USB 3 cable with their devices.
These cables do technically meet the requirements of a USB 3 cable, but, are often not super speed, not gen 2, and will not universally function at higher speeds.
Other customers have reported similar issues of non-connectivity, disconnections, or, being limited to slower speeds with our Allegro Pro card before as well.
These cases were resolved by the use of a higher quality and fully functional USB 3 cable.
We also note that some USB devices use a USB-C to USB-A port, but our cards only have USB-A or USB-C, necessitating the need for an adapter cable.
We do not know specifically which types of USB adapter cables you would need, but we can recommend a cable similar to these USB cables from Tripp-Lite, Cable Matters, Belkin, or Monster (if you can find the Monsters for cheap)
We would recommend only buying one of the cables, and testing it with one of the devices. Make sure that the cable is listed as ‘10Gbps compatible’ or ’super-speed, high-power, certified’ or similar.
If you are still having trouble, this may be a problem due to a voltage drop in the USB cable. Using a shorter or thicker cable can end up being the correct cable for your application, particularly for complex devices like the BMD.
In general, these cables should work with USB peripherals drawing up to 2A of current:
Type........Power-Carrying Wires....Cable Outside Diameter....Maximum Cable Length
USB 3..........20 AWG...............................6.0mm..............................1m ( 3 ft)
Generally, the gauge of the power-carrying wires can be inferred from the cable outside diameter.
3) Your Mac computer, or the USB/other peripherals, may require additional setup for best connection.
Make sure to disable FileVault, and similar encryption programs, and any anti-virus programs you may have.
You can try using the Apple Startup Security Utility to set External Boot to "Allow booting from external media” and “No Security." If this is already set, you must set it to "Disallow booting from external media”, “Full security” then restart, then set to "Allow booting from external media”, “No Security”, and restart again.
You can also try to disable SIP then test again, but we only recommend this if you feel comfortable with recovery console, Terminal commands, and modification to macOS.
Also, does the USB device or Hard Drive have (or require) a firmware/software update for optimized usage? Is there additional USB/HDD software required or recommended for use of these?
We have seen that some connected peripherals may need additional updates to function well, or, macOS security can prevent these from working (see above).
4) Regrettably, some peripherals or their software, may not be compatible with the chipset used on the card (ASMedia ASMx142)
Your USB peripheral OEM may also have other drivers, updates, or information available directly from their website.