It's all about the bandwith? (USB)

[daveleau]

Well, I got an error tonight from my wierded out USB situation. It said that there was a bandwith limitation. I had tried to use my camera to take a pic (USB Log. Quickcam) and it said that I didn't have enough bandwith to do so. It gave me two percentages- 1-- System sequestered resource of 14% and 2-- camera usage of 23%. It didn't say anything about my speakers. I guess they are taking up close to 60-70% of my 'bandwith' for USB. I am going to begin research on this but if anyone has any info- Please post it here!!! Thanks a bunch.
Dave

[daveleau]

Here's info I found on IDG.net...

Q8: How many USB peripherals can I connect at once?
A8: Technically, you can connect up to 127 individual USB peripherals at one time. Due to the fact that
some devices reserve USB bandwidth, the practical maximum of devices is less than the theoretical
maximum. However, PCI-USB add-in cards provide an independent USB bus to which even more
peripherals can be connected.


i guess one fix would be to get an extra USB card to run speakers by themselves since it has separate bandwiths. What is bandwith anyway?

[Vampiel]

Didnt you say that you have USB speakers as well as a USB mouse? Well each USB device should be on its own USB port that it is connected to, therefore should have its own bandwidth. I dont use USB and dont know much about it exept that it goes around 8-10mb/sec, so could some one confirm me on this? This is probobly the easiest way to make exaclty what bandwidth is clear to you :
Think of it this way
Cable modem bandwith=garden hose hooked up to house
ADSL=straw with someone blowing water into it
The cable modem has alot more bandwidth cause it signal has more room to travel in/and is hooked up to more powerfull source, but you have to share it with more people.
ADSL has less bandwidth cause it only has a small amount of space to travel in/not as powerfull signal, but you dont have to share it with anyone.
Say you had a cable modem and 3mb bandwidth allocated to your line (thats alot for cable modem) and you had 3 people on. The max each of you could get is 1mb/sec at one time cause that would MAX out your bandwidth. Reletively say your HD reads at 10mb/sec and you had 3games open, but each game required 100% of your HD's reading speed so each game would slow down alot and could only read at 3.3mb/sec cause of the bandwidth.
In a nutshell its how fast the device can send/read/travel/etc...

[daveleau]

Thanks Vampiel that explains bandwith really well.

As for USB, I have found that USB has a 12 MB bandwith limitation. USB speakers take ALOT of it. Much more than other USB devices. All devices on one USB controller have to share that bandwith. If you want, you can get a second USB controller card and get another 12MB bandwith. Thus, I can run the USB speakers off of one controller's bandwith and everythin else off of the other.

Seems like alot to go through but...