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More than two USB harddrives

Posted: Sun Mar 04, 2007 4:06 pm
by TP_user
I have a T43 which I can attached two 2.5" 60G USB harddrive to it using the ports on the TP. But when I use my TP as a desktop, I will use one USB ports for a large key board and mouse. That left me one port for one of my 60G USB drive. I want to use both my 60G USB drives , so I went out to buy a powered USB hub. But I am not sure if this external USB hub is not giving enough juice to the 2nd hard drive or whatever other reason, the drive on the USB hub is not recognised. I also have an external 3.5" USB hardrive and an external 5.25" CD writer which both have there own power supply. I have no problem connecting them to my T43 through the USB hub. So I think the USB Hub is working.
Any idea how I can get this working ? Any one has successfully connected more than 2 2.5" USB HD which do not have external power to the TP through a powered USB hub ?

Posted: Sun Mar 04, 2007 4:26 pm
by gator
A simple and cheap solution will be to get a USB Y-cable (with two two heads) and connect your USB drive to two ports on the hub (provided you can spare one more port). That usually solves the problem. Meritline and PCMicrostore usually have this cable really really cheap (<$5).

Re: More than two USB harddrives

Posted: Sun Mar 04, 2007 4:27 pm
by Ken Fox
In my experience, if the issue is the power going to an external USB 2.5"drive, then you will hear "clicking" sounds coming out of the hard drive (put your ear near to it) and if there is a light on the USB box, it will not light properly.

USB devices although mature are not what I would call "bug-free." I have varying amounts of difficulty with these devices on my laptops AND on my desktops. If the hub is truly powered independently, as by a plug in adapter, there should be enough juice to power your drives. It could be that the adapter you have for your hub is not supplying enough power for more than one peripheral. Perhaps you should plug the keyboard into the hub if it is plugged in directly to one of the ports on the T43.

Other ways of hooking up your drives would include using a powered PC Card USB hub, an ultrabay adapter, and a docking station.

Posted: Mon Mar 05, 2007 12:15 am
by TP_user
Thanks a lot Ken. How much power should the powered USB hub power adapter supply ? My powered hub has a 5V 1A adapter. WIll that be good for a 60G USB 2.5" drive ? Any idea how much power a 2.5" drive takes? I'll try to listen to see if the HD gave "clicking" sound as you described.

Posted: Mon Mar 05, 2007 12:40 am
by Ken Fox
TP_user wrote:Thanks a lot Ken. How much power should the powered USB hub power adapter supply ? My powered hub has a 5V 1A adapter. WIll that be good for a 60G USB 2.5" drive ? Any idea how much power a 2.5" drive takes? I'll try to listen to see if the HD gave "clicking" sound as you described.
I don't really know the answers to your questions. It is my impression that different drives draw different amounts of power, e.g. some are perhaps more efficient than others. I amp is not a whole lot of power and what is written on the adapter might not really be true if you evaluated the adapter with a multimeter or other similar measuring device. Some external USB2 boxes seem to do a much better job of supplying the power to the hard drive than others. For example, I have a combined USB2/FW box for 2.5" drives that cannot supply enough power to run any of my 2.5" hard drives that run fine in other boxes; that box needs to have an external 5v adapter plugged in even though the manufacturer did not supply one and did not say in any of the documentation that this was necessary. So somehow the circuit board in the box is squandering the power or not supplying it since those drives run fine in other USB boxes.

It is my opinion that most of the external 2.5" drive boxes out there are basically junk, although most will work to some extent and with some equipment. Perhaps this is explained by the fact that they sell for next to nothing these days, and the manufacturers are engaged in a race to the bottom.

Posted: Mon Mar 05, 2007 8:44 am
by Paranoid_TP_User
I have a hub that powers, amongst other things, a 2.5" hd. If you hold the 2.5" hd to your ear as you plug it in you should hear it spin up.

Try disconnecting the hub from your computer and then plugging in the drive to the powered hub while pressing it against your ear - it should spin up despite not being connected to the computer.

The thing about hubs as you have probably noticed is that each of the new slots needs drivers installed whenever a new device is connected. So connect up the drive and try searching for hardware that has not yet been installed?

Posted: Mon Mar 05, 2007 9:53 am
by Ken Fox
Paranoid_TP_User wrote:I have a hub that powers, amongst other things, a 2.5" hd. If you hold the 2.5" hd to your ear as you plug it in you should hear it spin up.

Try disconnecting the hub from your computer and then plugging in the drive to the powered hub while pressing it against your ear - it should spin up despite not being connected to the computer.

The thing about hubs as you have probably noticed is that each of the new slots needs drivers installed whenever a new device is connected. So connect up the drive and try searching for hardware that has not yet been installed?
Yeah, but this is supposed to happen automatically, Win XP just does it. Most of the time when portable self-powered USB2 2.5" drive boxes aren't recognized, it is a power issue. Virtually every time I've had this problem, if I powered the drive separately it got recognized later.

Posted: Fri Mar 09, 2007 5:24 pm
by TP_user
Thanks for the responses. I found the problem. After reading the fine prints on the harddrive , my 2.5" HD actually says it requires 5V 1A DC. My powered hub comes with a 5V 1A adapter. But this cheap adapters may not be providing 1A at all. I switched to a 5V 2A adapter and everything works. I just have to be carefull on watching if the hub heats up when more current can actually be drawn by the HD. I have been using it for almost 8 hours and the hub is just slightly warm. I hope it will last.