USB 1.1 devices on USB 2.0 Hub / External DVD-writer - bandwidth questions

[Batistuta]

Maybe not a wise question, but here goes:

I'm considering connecting ~6-7 USB 1.1 peripherals to a USB 2.0 hub since I believe this will give each peripheral their full 12Mbps bandwitdh - correct ?

Another question: I'm looking to buy the Sony DRX500UL external DVD+/-RW writer (with both usb2 and Firewire connectors), and cablewise it would be easiest to attach it to the above USB hub, but am I correct in assuming, that it will perform slower than on a firewire connection? And would it possibly bog down the other USB devices ?

Anyone with experience on external DVD-writers, especially regarding bandwidth and CPU usage ?

Thx.
B.

 

[Mingon]

Do you have a usb2.0 pci card at all? are you using them all at the same time ? if you only have a usb 1.1 card/mobo socket then you only have 12Mbps total to share. If you have a usb 2 card / mobo port then it would require a usb 2 hub to be able to share the 480Mbpd between all the devices.

Although USB in theory is faster I have found that firewire is (likely due to its maturity)quicker. My 30gb portable laptop drive has both, I get around 12mb/sec on usb2 and 14mb/sec on firewire. Personally I would not put the external drive on the hub - as with putting a cdrw on the same channel as the hard drive I wouldnt want to risks any potential hiccups - unlikely i know but if you have the firewire port available then use it.

 

[Batistuta]

I have a USB 2.0 equipped MoBo.

What kind of CPU usage are you looking at, when using your drive with the two connections?
I've seen reports of ~40% with external harddrives, with USB a little higher than Firewire.

I have a P4 1600@2400, but still, using an external soundcard (especially),usb mouse &keyboard will probably cost me some FPS's...
Will also hook up; camera,scanner,wheel/pedals and printer to the USB 2.0 hub (though not all will be running at once!)

Finally, I plan to run both cables (usb+firewire) for a distance of 5-8meters (15-25 feet) - does that pose any problems with signal strength? I remember seeing some special long USB extension cables somewhere.

Thx.
B.

PS. Does anyone know when Serial ATA drives and P4 Hyper Threading processors are scheduled to start volume shipping?! And in which sizes and speeds.

 

[Superman9534]

actually your theory is totally messed up. By putting USB 1.1 devices on a 480mbps USB 2 hub/chain will NOT give each one its full 12mbps bandwidth. By putting ANY USB 1.1 on a USB 2 port/chain will drop the ENTIRE bandwidth of the chain to a max of 12mbps!!! This is one of the problems with USB 2 as compared to Firewire. So USB2 on USB 2 ports and USB1 on USB1 ports, no other way unless you want a max of 12mbps.

So use the firewire, pick up a PCI card for like 20 bucks. I still think USB (1 and 2) is mainly for peripherals and not high speed devices. Firewire (and firewire 2 which will be 800mbps - 3200mbps) are definatly better for hard drives and CD-RWs/DVD-RWs.

 

[NFS4]

nm

 

[Eug]

Another question: I'm looking to buy the Sony DRX500UL external DVD+/-RW writer (with both usb2 and Firewire connectors), and cablewise it would be easiest to attach it to the above USB hub, but am I correct in assuming, that it will perform slower than on a firewire connection?

Hmmm... Just a note that an external DVD writer will not max out the speed of USB 2 (assuming that the port hasn't been slowed down by USB 1.1 devices).

Yes, IDE bridges for Firewire ARE much faster than for USB 2, but optical drives don't come close to maxing out even USB 2 to IDE bridge speeds. (Firewire - Oxford 911 - is much faster than USB 2 for hard drives though, especially for recent 7200 rpm desktop drives.)

Finally, I plan to run both cables (usb+firewire) for a distance of 5-8meters (15-25 feet) - does that pose any problems with signal strength? I remember seeing some special long USB extension cables somewhere.

Dunno about USB 2, but for Firewire the limit is 15 feet.

 

[Batistuta]

Harddrives is different from optical drives, with regards to bandwidth usage etc., I agree.

Just for the example; Maxtors external drives in the 5000 series with both USB 2.0 and Firewire: they state the sustained transfer at 34mb/s vs. 40mb/s for USB 2.0 and Firewire respectively.

For a 20-30' firewire connection, could a powered hub in the "middle" do the trick, with a 15' cable on each side, so to speak?

B.

 

[RichieZ]

Originally posted by: Batistuta
Harddrives is different from optical drives, with regards to bandwidth usage etc., I agree.

Just for the example; Maxtors external drives in the 5000 series with both USB 2.0 and Firewire: they state the sustained transfer at 34mb/s vs. 40mb/s for USB 2.0 and Firewire respectively.

For a 20-30' firewire connection, could a powered hub in the "middle" do the trick, with a 15' cable on each side, so to speak?

B.

Thats BS, I have a WD1000JB (special edition) in a firewire/USB2 enclosure, I'm thinking that they use some cheap firewire bridge while I have the oxford 911 bridge(fastest on the market) and it gets 30MB/s across the disk and a burst speed of 34MB/s. Also there was an article i saw linked here that compared speeds of firewire vs USB2.0, firewire won out.

 

[Batistuta]

USB 2.0 vs. Firewire speed - Maxtor external harddrive

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B.