USB length max ??

2poor4mods · 09-08-2006, 01:26 PM

Hello all,

A brief introduction to my question:

I acquired a Lacie External CD/DVD player that has an option to use a USB as power from a powered port. I am dedicating a 4 port powered hub just for this device as to not upset the power sent to it. The hub is powered by the smaller 4pin connector (the kind that powers a HD) from my OPUS 90W (via splitter/adaptor) My computer is located in the trunk, and I thought that I could mount the USB hub near the computer in the trunk, and then run a long USB to the drive located in the dash. However, I heard that there could be power loss running a powered USB cable from 10-15 feet. Has anyone experienced this?

Or should I just play it safe and mount the 4-port hub in my center console and extend the power wires from the OPUS to the hub; and from there run the USB cable to the drive thereby eliminated the length problem all together. It's just more work to mount the hub and extend the wires.

Any thoughts or comments would greatly be appreciated.

Sorry I couldn't keep it more brief than that.

TIA

RedGTiVR6 · 09-08-2006, 01:41 PM

mount it in the center console.

I've heard the limit on USB is 16 feet.

pepsibobby · 09-08-2006, 04:58 PM

yep 16 feet without a powered hub. I had that same prob and had to move my whole computer just to use the TS.

turbocad6 · 09-08-2006, 05:08 PM

first of all there are usb extenders, called repeaters..., that'll give you more than enough length, & there not to expensive...

& 16' is just the usb standard, doesn't mean it won't work at 20' & doesn't mean it'll work at 12'....

my advice to you is, you really don't need a hub, what I would do is try it first with just a usb extention cable...if it's a no go, I would then give the drive a power plug... theres no reason not to, if it's a burner it'll help alot more than a hub, which is only going to give you 500ma on each port regardless of weather the other ports are used or not from the hub in most cases & with most hubs....

the option for usb powered is just a convienience for portable laptop use, & to not have to provide power, but in a permanent mount power should be provided for the best reliability...

2poor4mods · 09-08-2006, 06:41 PM

Thanks for the responses. It is a burner and although I won't be burning much while driving, I might as well give it constant power.

Am I right by assuming that I can do the same thing as I am with powering my TS? which entails cuting the AC adaptor, extending the wires, then attaching it to a 4 pin molex to the correct terminals (in this case 5v and ground) and connecting it to the OPUS? Or is it more complicated than that? Now I just have to figure out which wire is which

Also, what gauge do you think will suffice? would regular speaker wire do?

Thanks again

jschrauwen · 09-08-2006, 07:28 PM

Quote: Originally Posted by 2poor4mods

Thanks for the responses. It is a burner and although I won't be burning much while driving, I might as well give it constant power.
Am I right by assuming that I can do the same thing as I am with powering my TS? which entails cuting the AC adaptor, extending the wires, then attaching it to a 4 pin molex to the correct terminals (in this case 5v and ground) and connecting it to the OPUS? Or is it more complicated than that? Now I just have to figure out which wire is which

Also, what gauge do you think will suffice? would regular speaker wire do?
Thanks again

That's what I have found from my questions and searches here. Remove the AC end of of the barrel plug power line, use a multi meter to confirm wire identity (continuity test) after it's been cut. The center inside portion of the barrel as + and the outer as - (in most cases).

turbocad6 · 09-08-2006, 07:34 PM

14 gauge speaker wire would do fine, but I think your better of getting a small roll of black & red wire, same as speaker wire, radio shack should have it still... will look more "correct" & reduce the chances of hooking it up backwards....

14 gauge may be a little overkill, but if you ever need 5v up front for something else, it's already there & can support another load... if this doesn't concern you, 16 gauge will be ok...

SentraVIP · 09-10-2006, 10:59 PM

I've tried hooking up USB thumbdrive on a 5.5m extention cable. Works ok. But when hooking more than 1 usb devise (using a powerd hub, unplugged), it will not work (the light didn't lit up, so I thought it must be a power related issue).

I haven't tried hooking up a optical drive on the extension though. Maybe if it's powered by some other sources (besides from the USB cable), it will work?

Maheriano · 09-11-2006, 12:32 AM

I have 2 six foot extensions going from my monitor to my computer in the trunk. Works fine.

RedGTiVR6 · 09-11-2006, 06:35 AM

Quote: Originally Posted by SentraVIP

I've tried hooking up USB thumbdrive on a 5.5m extention cable. Works ok. But when hooking more than 1 usb devise (using a powerd hub, unplugged), it will not work (the light didn't lit up, so I thought it must be a power related issue).

I haven't tried hooking up a optical drive on the extension though. Maybe if it's powered by some other sources (besides from the USB cable), it will work?

Think about how electricity works.

USB cables don't carry much power down them at all.

You have to power the hub to get more power down the cable.

If you're having trouble and are using what should be a powered USB hub, and you're not providing power to it...it's probably a good idea to try and power it.

Philhop · 09-11-2006, 06:24 PM

Hey , A tech question.

I have about 4 , 5m lenght runs of USB cable

One for my Ipod , one for my USB soundblaster , one for my touchscreen , one for a keyboard and mouse splitter , also im running Wifi GPS and a bluetooth usb .

I find that my usb speeds are slow and sometimes my audio stutters, would this be because of the lenghts of usb cable im using

turbocad6 · 09-11-2006, 11:55 PM

no way, usb 2.0 is like 480mbps.... that's fffffaaaaaaassssssstttttt!!!

cable length isn't a factor... are you sure your using a high speed cable? is it on a 2.0 port?... I'd look more at your processor load & stuff if the cable & port is good...

Philhop · 09-11-2006, 11:58 PM

Im using 6 diffrent ports , im sure its high speed usb 2.0 and usb to motherboard connectors , my ipod transfer speeds dont got 480mps they go slow!!!! I dont know what it is. Mabey its the via epia1300 mobo drivers but ive tryed everything.

teddyking · 09-13-2006, 03:38 AM

Is there any DIY use self power guide ?

i have 5 m usb cable male-female which is connect to wifi usb and it doesn't work.My PC can't detect wifi adapter but when i try connecting with usb thumb
drive it works fine.

ElKeeed · 09-13-2006, 06:33 AM

Quote: Originally Posted by Philhop

Hey , A tech question.

I have about 4 , 5m lenght runs of USB cable

One for my Ipod , one for my USB soundblaster , one for my touchscreen , one for a keyboard and mouse splitter , also im running Wifi GPS and a bluetooth usb .

I find that my usb speeds are slow and sometimes my audio stutters, would this be because of the lenghts of usb cable im using

This is not because of the length but the type and number of devices. 6 ports on your pc are not independant but act as 2 or 3 hubs. If you use a usb 1 device it downgrades other devices on the same hub to usb 1 speed.

So you need to work out which ports are on the same internal hub, then make sure the USB 2 devices and USB 1 devices are not mixed.

You may also have problems due to power with that many devices. These can be solved by using a powered hub (and powering it seperately!).