I use a large Wacom tablet. Will a Mac KB deliver enough power for it?

It worked. Thanks for the tip about the rear USB ports. If their extra wattage is noted anywhere, I either never read it or forgot it. I tried a 10-inch cable from Amazon and, initially, received the popup telling me I needed a more powerful USB source, so I figured the cable was defective, & started the return process. But I then tried the rear ports, and in spite of no changed information in the system report (rear ports listed at 500 mA, but the tablet, KB and mouse draw 618mA together), the keyboard, mouse, and tablet all work fine. No popups.

Change of plans. I started looking through the system report and comparing the stats on my computer to what info I could find in the Mac Knowledgebase about maximum amperage in the USB buses. On my Mid-2010 Mac Pro all of the USB systems are set to max out at 500 mA (even the rear ports, which can handle a bigger load) , so there is a line for each bus indicating that maximum, followed by a line indicating what the existing current demands are, and a final line indicating if/whether there is any additional current draw on that bus, and how much. But in spite of the extra demands of the Large Wacom tablet, which should have invoked "Extra Operating Current", none was shown for that bus in the System Report. In fact, No Extra Operating Current showed up anywhere in the report. That looked to me as if details were being ignored, and the USB bus could be functioning without any "headroom", that is, maxed out with no room for spikes or surges. So I unplugged the tablet, plugged it into a separate usb port, and ordered a 3A powered USB-3 hub for the KB-mouse-tablet combination I want to wind up with. Maybe the system could handle it, but I'd rather err on the side of caution. Note-I found out that the tablet draws 500mA by itself.