Go Back   AnandTech Forums > Hardware and Technology > General Hardware

Forums
· Hardware and Technology
· CPUs and Overclocking
· Motherboards
· Video Cards and Graphics
· Memory and Storage
· Power Supplies
· Cases & Cooling
· SFF, Notebooks, Pre-Built/Barebones PCs
· Networking
· Peripherals
· General Hardware
· Highly Technical
· Computer Help
· Home Theater PCs
· Consumer Electronics
· Digital and Video Cameras
· Mobile Devices & Gadgets
· Audio/Video & Home Theater
· Software
· Software for Windows
· All Things Apple
· *nix Software
· Operating Systems
· Programming
· PC Gaming
· Console Gaming
· Distributed Computing
· Security
· Social
· Off Topic
· Politics and News
· Discussion Club
· Love and Relationships
· The Garage
· Health and Fitness
· Merchandise and Shopping
· For Sale/Trade
· Hot Deals with Free Stuff/Contests
· Black Friday 2014
· Forum Issues
· Technical Forum Issues
· Personal Forum Issues
· Suggestion Box
· Moderator Resources
· Moderator Discussions
   

Reply
 
Thread Tools
Old 11-20-2012, 02:18 PM   #1
jeffason
Member
 
jeffason's Avatar
 
Join Date: Dec 2003
Location: Phoenix, AZ
Posts: 100
Default USB 3.0 power to USB 2.0 device?

Hello all,

I leverage my Android smartphone's USB tethering support for internet sharing frequently and I am finding that the 500ma power output from USB 2.0 is not sufficient to maintain a charge over long periods of time with heavy use. I did some research and found USB 3.0 outputs 900ma which I think should be enough to maintain a charge while tethering under these conditions.

If I were to purchase a USB 3.0 PCI-E expansion card for my desktop would I be able to send the USB 3.0 power output to a USB 2.0 device? Does it depend on the driver manufacturer? I noticed in the Windows "USB Root Hub" properties there are sections pertaining to power (not sure how to control it, though).

I actually did purchase a USB 3.0 PCI-E card to try it out but I'm having issues with it even working properly for my USB 2.0 device. I also noticed that the associated "VIA USB 3.0 Root Hub" device in my device manager did not have the same power options as the Windows USB 2.0 drivers do.

I also thought that maybe there is an adapter I could get and plug 2x USB 2.0 ports into then from the adapter go to my phone to provide additional power?

Is any of this possible? Do you have any recommendations or success stories for trying to do anything similar?

Thanks for any insight/tips!

Jeff
__________________
Jeffason's Heatware
jeffason is offline   Reply With Quote
Old 11-20-2012, 06:00 PM   #2
shabby
Diamond Member
 
shabby's Avatar
 
Join Date: Oct 1999
Posts: 4,680
Default

Since the phone is going to detect a usb cable its only going to pull 450-500ma from the port. Some kernels allow fast charging that will trick the phone thinking its plugged into the ac outlet when its simply connected to the usb and will pull up to 1a from a usb port.
You can also try a usb charging cable, its only good for charging, but i guess your usb tethering wont work.
__________________
I'm on a boat!

R.I.P. PrideFC
shabby is offline   Reply With Quote
Old 11-20-2012, 07:04 PM   #3
jeffason
Member
 
jeffason's Avatar
 
Join Date: Dec 2003
Location: Phoenix, AZ
Posts: 100
Default

Thanks Shabby. I am one step closer. I did some research and believe my kernel does support fast charge. I found an app to enable it, as well.

However, USB 2.0 still cannot send more than 500ma, correct? So, I'd need this trick in combination with a USB 3.0 port to gain any benefits?

If I'm on the right track here then could anyone recommend a good USB 3.0 PCI-E expansion card? I'm really not liking the USpeed one I bought which is not playing nice with my USB 2.0 devices.

Thanks again for any insight or product recommendations.
__________________
Jeffason's Heatware
jeffason is offline   Reply With Quote
Old 11-20-2012, 08:59 PM   #4
mfenn
Elite Member
Super Moderator
General Hardware
 
mfenn's Avatar
 
Join Date: Jan 2010
Posts: 20,962
Default

Quote:
Originally Posted by jeffason View Post
However, USB 2.0 still cannot send more than 500ma, correct? So, I'd need this trick in combination with a USB 3.0 port to gain any benefits?
Depends on your exact setup. Many laptops and motherboards provide USB charging ports that output over 1A. You can also use a Y cable to get 1A of power draw from two USB 2.0 ports.
mfenn is offline   Reply With Quote
Old 11-21-2012, 12:41 AM   #5
jeffason
Member
 
jeffason's Avatar
 
Join Date: Dec 2003
Location: Phoenix, AZ
Posts: 100
Default

cool, thanks mfenn. going to try out a y-cable that some other smartphone users reported success using.

appreciate the help y'all!
__________________
Jeffason's Heatware
jeffason is offline   Reply With Quote
Reply

Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -5. The time now is 02:09 AM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.