Not much to troubleshoot with USB (Assuming the Mac is slow that is physically hooked by USB to it.) Just replace the USB cable.
If it works fine on the USB connected, but the Macs connected to the share have slowness, then you would need to look into how the shares are handled.
Sorry, my bad, it is connected via USB to a Mac, and other Macs print to it via print sharing.
Can be any of a thousand things, but port configuration is a good start. I will assume it is a network printer and not USB.
And since you didn't mention an OS, I will go with Win 7 (By far the most common)
First things first, modify the port in the driver to use LPR instead of RAW, and make sure nothing else is checked
So go into your Control panel and then into Devices and Printers.
Right click on the printer and go to Printer Properties. Then go to Ports > Configure Port and make sure your setup matches this (Obviously your IP will not be the same)
Now go to the Advanced tab and make sure that Enable advanced printing features is NOT checked
In General, that should greatly increase the speed of printer spooling as well as settings retrieval. To go any more in depth would require a lot more to begin with than "Prints slow"
After sending a priont job, it takes, literally, two minutes or so to begin printing. And, on multi-page jobs, after printing the penultimate page, it'll pause for a minute or two before printing the last page.
Googling isn't helping. What can I be looking at?