I'm running a Sager NP 4750 laptop.

I wish to buy 2 2.5" (notebook) disks, one around 60 GB, the other 100+ GB (preferably quite a bit more). I would like to mount these disks in UNpowered USB cases. Therefore, if my understanding is correct, each drive must consume no more than about 450-500 mA to run on a typical powered hub drawing 1 amp through a power supply and additional power from the on-board USB.

QUESTIONS:
1. Is my power estimate reasonable under the circumstances? (Ask more questions if needed !

2. Does anyone know who (manufacturer, other vendor) makes such drives that really do consume low power, at or below the target I've expressed.

3. Does anyone recommend a brand/model for the cases to put them in? I'm presently looking at the CPUE205 and CPUE215 (adds firewire) from CP Technologies (www.cptechusa.com), but I'm totally open-minded.

4. Has anyone used the little USB hub (for its size, not its capacity) from the same vendor, model CP-UH-135? Other recommendations?

Thanks to all!

Elchanan

maybe you can consider this : Thecus N1050.

It comes with power pack using battery, called OTG ( on the go).

Power:
USB bus power
USB-DC power or
external AA battery

http://www.newegg.com/Product/Prod [...] 6822102003

Thanks for this! I found a couple of very positive (and meaningfully detailed) reviews by other owners of this unit, will explore it further.

I've used N1050 for a while, very good.
The case is mirrow like black which is very stylish...but will get the finger print on it very easily like Ipod Nano.

Yes, thank you so very much for your feedback. I am looking into this one!

How's the battery life?

Elchanan

The one with the battery sounds kewl :-D

Here are some unpowered ones:

http://www.newegg.com/Product/Prod [...] &maxPrice=

and some powered ones:

http://www.newegg.com/Product/Prod [...] &maxPrice=


Good luck :-D

Thanks. I did order 2 powered enclosures from CP Technolgies to try, the CP-UE-205 and also the CP-UE-215. The latter is identical to the former, but also supports firewire. And the people at CP Tech are very available.

One thing I've stumbled upon is that, apparently, not all USB hubs distribute power among their respective ports in the same way. Apparently, some pass power from port to port, so that all unused power is available to the downstream ports. In contrast, other hubs apparently "partition" available power evenly among their ports. In the latter case, with a hub greater than 4 ports, a 1 Amp power supply simply will not support the 500 mA USB standard. I'm not sure I have this information correct, I'm just piecing together from bits I'm reading here and there.

Also, for those interested, HItachi just announced a new series of its TravelStar drives, dubbed 5k160. These apparently have the lowest average power consumption of any 2.5" drives available, well under 400 mA. So hopefully they will "just work". However, I believe they may be expensive, and in any event they do not appear to be available yet.

Also ordering the Thecus N1050 to try it out.

QUESTION: Has anyone who owns the N1050 used it with a DC power supply? If so, would you be willing to share the power specs (as in 5 volts, 5 watts, 1 amp, that sort of thing)?

watts = volts x amps

So we can calculate the third if we have any 2.

Best to all,
Elchanan

http://www.newegg.com/Product/Prod [...] 6822102003

http://www.thecus.com/products_spe [...] id=1&pid=7

The external power pack apparently takes 1, 2, 3 or 4 AA batteries so that's

1.5V

3.0V

4.5V

or 6V

@ 1200 - 1500mAh per battery

It looks like it takes only 1 or 2 but it's hard to be sure from the pictures.

I don’t know if this help you,

But I’m on my 3 enclosure now.

It's an Archos ArcDisk20.

One think that draw my attention was that this drive didn’t need to use the external power (out of Ps2 port or from another USB port).

One day I was using one of the USB cables that came with the Archos drive with one of the "older" drive enclosures, and to my surprise the drive worked without the need of extra power. What?!

Then to my surprise if I used the cable of the Archos drive on the others USB "older" enclosures I never get power problems.

So to tell you the CABLE that connects the drive is extremely important!!!
More important than the power consuming of the drive. In fact I was looking for good cables as the ones that came with the Archos drive, but until today no good.

I hope I could help with this.

Hi all,
I"ve written off to Thecus with various questions about batteries (number required, rechargeables, Lithium) and DC power supplies.

And GloriosoSLB, your comments REALLY ring home as I read them. Recently, I had an upgrade installed by Comcast cable, and they changed the cable running from the wall to the cable box. We got a 2dB improvement in the signal getting through!

QUESTION: Does anyone know how to determine and/or where to buy "high quality" USB cables? I assume this means they are shielded, have gold-plated connectors, that sort of thing.

http://www.newegg.com/Product/Prod [...] x=0&Go.y=0

Hope this helps :-D

One "special" thing about the Archos cables is that both are too "large" (or fat, I can’t find the word), comparing to the others.

Other thing that may help is the length of the cable, the link provided by linux_0 show quality cables but lack shorter than 6FT (1.8m). I think that a shorter cable could help too. But I’m talking all theoretically here, because I never saw cables smaller than 6FT (1.8m) selling.

Thanks. I'm presently researching cables from Monster Cable, in California. They appear to have far and away the best USB cables, though somewhat pricey. Still, they cost a pittance when I consider the amount of time and energy this problem is sucking up.

Also, I've really concluded that the problem is in the hubs first, and elsewhere second. The promise of USB was that one device, a hub, would adequately power everything connected to it, up to 500 mA PER DEVICE if the hub has an external power source. But most 4+ port hubs are sold with power supplies that provide 1 Amp or less of power, so it is mathematically impossible to power multiple devices at anywhere near 500 mA per device, there simply is not enough current.

So I am presently looking into a company called Digi International (www.digi.com), which seems to have a better grasp on the situation, shipping 4 and 7 port hubs with a 3 Amp power supply. That would definitely work on the 4 port and should work on the 7 port, unless one connects high-power devices to all 7 ports at once.