[mythtv-users] MythTV and USB hubs

Brian Wood beww at beww.org
Thu Mar 16 17:32:46 UTC 2006

On Mar 16, 2006, at 10:24 AM, Jim Minihane wrote:

> Is there any reason I can't use a USB 2.0 hub to connect 4 Plextor  
> M402Us
> or  other USB capture device to a MythTV backend? I understand that  
> the
> Plextor 100U doesn't have hardware encoding so would require more
> bandwidth. But USB2.0 is 480Mbps. Thats a LOT of video. Any issues  
> anyone
> knows about? The idea of getting away with just the onboard USB  
> ports is
> attractive.
I don't know for sure about any problems, but I do know that in the  
real world that "480 Mbps." is seldom if ever achieved.

That bandwidth is shared among all devices on the bus, and if you  
have a hard drive or two that will slow things down. Hubs can hurt as  
well, as can buggy motherboards and bad drivers.

Firewire is officially slower than USB 2.0 (400Mbps.) but I think the  
world opinion is that it is faster in real-world applications than USB.

I don't know what the actual sustained bandwidth limit of USB-2 is,  
but I can guarantee you that it is less than 480Mbps. Still, it might  
well be adequate for what you describe.

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