How many drives.

[dcmaccam]

How many drives can you safely power from a 2019 iMac 27inch. It has 2 Thunderbolt and 4 USB3 ports. I have a Lacie SSD 1TB and a Lacie 2TB HDD via TB1/2 to TB3 adapter connecter to the Thunderbolt ports.

Would it be safe to connect a 3rd drive to one of the USB3 ports or would there be a risk of overload?

 

[chabig]

If the device has its own power port, you should probably use it. If the device doesn't have its own power it's ok to power it from the USB port. From what you told us, I think you should power the 2TB HDD from its own adapter. The 1TB SSD doesn't have a power port, so it can plug in directly.

 

[DeltaMac]

Your iMac will warn you if a device on a USB port is using too much power.
Full size (3.5-inch) drives will have a separate power cord/power brick, known as "self-powered"
External SSDs, or laptop size hard drives usually get power for the drive through the USB connection, known as "bus-powered"
Just plugging a device in to USB does not use a significant amount of power.
Self-powered devices don't get a significant amount of power through the USB cable.
If your 3rd drive has its own power connection, you will be fine.
A bus-powered device should also (usually) be OK. Your USB 3.0 ports can offer more power than older USB 2.0 ports, and the TB3/USB-C ports also can provide fairly high current to an external device.
Again, if there is a power issue on a USB device, your Mac will warn you about that when you attempt to connect that device.

 

[dcmaccam]

Ok Thanks for the info👍🏻

 

[Fishrrman]

A powered USB hub could take care of "the power problems" for you...