Pen drive different power consumption

[stephensaw]

Hi,

My USB keyboard got 2 USB ports, I've used one port for my Wacom tablet, then another spare for my USB pendrive, I got 2 4GB pen drive, but I can only use 1 of the pen drive on the port, the other one will show USB Hub Power Exceeded error message, is every pen drive have different power consumption? How to check the power consumption of a USB drive?

Thanks!

 

[stefo]

My USB keyboard got 2 USB ports, I've used one port for my Wacom tablet, then another spare for my USB pendrive, I got 2 4GB pen drive, but I can only use 1 of the pen drive on the port, the other one will show USB Hub Power Exceeded error message, is every pen drive have different power consumption?

Yes.

How to check the power consumption of a USB drive?

you can't most of the time. unless the maker list minimum current requirement like say 150mA with 5V.

your wacom is relatively more power hungry than a flash drive. i know cos i used 3 wacoms so far. i plug that directly to the usb on the back of pc.

i think USB 2.0 only supply 0.5A or 500mA per USB port. That's not sufficient for multiple devices.

 

[sminlal]

As stefo indicated, a USB port can only supply 500mA - when you plug an unpowered hub into a USB port that 500mA gets split up between all of the devices you plug into it. If the total draw of all the devices exceeds 500mA, then you've run out of power.

You should either plug the high-power devices (probably the tablet) directly into a USB port on the computer, or use a powered hub (a hub with a power cord that plugs into a wall socket as well as a USB connection to the computer).

 

[stephensaw]

Thanks! Another question, when i plugged in my tablet, I can't boot my pc, it stuck at the screen where it say Press tab for something and Del for bios, and my tablet keep blinking, i can boot if unplug the tablet.

Is it something to do with the power? Thanks, and sorry for irrelevant question.

 

[stefo]

probably. could also be a bios thing.

what power supply r u using?

 

[stephensaw]

probably. could also be a bios thing.

what power supply r u using?

I'm using Silverstone Element ST75EF 750 Watt Power Supply.

 

[stefo]

nice psu.

i can only think of a motherboard bios issue.

i have a boards with this issue, not with a wacom tablet but a a dell monitor built-in card reader. annoys the monkeys out of me.

may be u could try placing a usb hub between the wacom and pc. use that hub only for the wacom.