# Are all external harddrives created equal? **URL:** \ **Category:** Factual Questions\ **Created:** [April 27, 2008, 8:53am UTC](https://boards.straightdope.com/t/are-all-external-harddrives-created-equal/447066 "2008-04-27T08:53:40Z")\ **Posts on this page:** 2\ **Page:** 2
**Author:** ![Mangetout](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mangetout/32/19_2.png) [@Mangetout](https://boards.straightdope.com/u/Mangetout)\ **Post date:** [April 28, 2008, 7:53am UTC](https://boards.straightdope.com/t/are-all-external-harddrives-created-equal/447066/21 "2008-04-28T07:53:25Z")
[QUOTE=astro] I think you’re confusing the notion of a [URL=[USB hub - Wikipedia](http://en.wikipedia.org/wiki/USB_hub)]bus powered vs a self powered hub [/QUOTE] I think you might be understanding the term ‘hub’ to mean _an external device plugged into a USB port to provide more ports_. I’m pretty sure **Quartz** is talking about (or including) _root hubs_ - of which there may be one, or several, built into a motherboard, or on installed PCI cards. There is a maximum current supply rating _per hub_ in this context - and it’s this that often imposes the limits. ---
**Author:** ![Quartz](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/quartz/32/267_2.png) [@Quartz](https://boards.straightdope.com/u/Quartz)\ **Post date:** [April 28, 2008, 8:11am UTC](https://boards.straightdope.com/t/are-all-external-harddrives-created-equal/447066/22 "2008-04-28T08:11:57Z")
[QUOTE=Mangetout] I’m pretty sure **Quartz** is talking about (or including) _root hubs_ - of which there may be one, or several, built into a motherboard, or on installed PCI cards. There is a maximum current supply rating _per hub_ in this context - and it’s this that often imposes the limits. [/QUOTE] Absolutely correct. I should have been more precise. [Previous page](https://boards.straightdope.com/t/are-all-external-harddrives-created-equal/447066.md?page=1)