Bekijk de volledige versie : Need help with power hungry USB HD
Hi everyone, I hope someone here can be of assistance:
I recently bought a Seagate FreeAgent Go 160gb USB HD that obtains power from the USB port. I bought this drive fully aware that the WL-500gp may not be able to supply enough power from a USB port to actually spin up the drive. However, the Seagate HD comes with a 2 headed cable to obtain power from both ports, and I was under the impression that this would be sufficient after reading a few posts on here, so I went ahead and bought the drive.
The problem is that the HD fails to spin up with BOTH USB heads plugged into the WL-500gp. If I take the dedicated "power" head and plug it into my laptop with the "data+power" head still plugged into the WL-500gp, the HD works.
Ok, so the solution is to buy a powered USB hub right? Well, I don't want to, I don't want ANOTHER inefficient power adapter plugged into my wall sucking away at power, after all, the reason I'm running the WL-500gp setup is to save power over my old PC I was using previously.
So, my quesiton is, what are the other options? Can I buy a 5V 3A (3.5A, 4A?) adapter and use that to power the WL-500gp, will this give the USB ports more power? What about powering the WL-500gp from the USB port itself? If I buy a USB hub and plug it into the WL-500gp, can I disconnect the WL-500gp's power adapter and have it still run? Any drawbacks to doing this? What about other ideas?? I'd like to hear them.
I've got a WL-500gp v1 running Kamikaze.
Thank you.
Untouchable
10-07-2008, 07:21
What about powering the WL-500gp from the USB port itself? If I buy a USB hub and plug it into the WL-500gp, can I disconnect the WL-500gp's power adapter and have it still run?
Yes you can disconnect routers' power adapter and it will still run from the power of usb hub.
Untouchable
11-07-2008, 15:18
Although I'm not 100% sure... when I removed power cable from wl500gp, leds stayed on, not sure if hdd didn't spin down...
Ok, after brainstorming for a while, I managed to get my setup mostly working.
What I did was splice the power adapter cable and T off the power to a female USB connector and the router's plug. Doing this allowed me to plug the "power only" USB head from my HD into the female connector, giving the HD all the juice the power adapter can provide, rather than having the router limit the current to 500ma.
However, I did say "mostly working" because the drive seems slightly unstable. I tend to get read errors occasionally, so I will have to look into it more.. There are certainly no more click-click spin up errors anymore though, so I'm definitely closer. I'll probably buy a 3000ma adapter and attempt the same setup.
Will report back on my findings.
Loopy Byteloose
19-07-2008, 16:49
First off, I suggest you fully test your external HDD unit with a conventional PC or laptop. There is always the possilbity that one has a defective unit and before jumping into using it with the AsusWL500gP, you might feel better knowing it worked well on other platforms. Seagate has said it does not support Linux on these external drives and you are on your own. It is important to feel you have a good unit. I have tested mine overnight with my Asus Tualitin desktop PC and Windows XP Pro. Also I have tested it with my Asus EeePc with Xandros Linux.
For me, it seems to be working fine with both. So I am ready to go ahead with the WL500gP setup.
The bottom line is how many milliamps does the unit require? The range is somewhere between 200ma and 1000ma if you read the USB specs. I really don't know, but with one connector, the maximum is 500, the minimum is 100, and with two it might be as high as 1000 milliamps. The AsusWL500gP power supply is 3000 milliamps, so it might be enough for both. But overclocking the WL500gP would make it drastically use more power [not a good idea] that may be needed for the Seagate Hdd. Underclocking the WL500gP would reduce the power consumption and the heat.
You might have the power only side of the Y cable go to an independent well-regulated +5v supply +/- 5% and about 1000 milliamps. You either have to find a USB male plug or cut off the existing fitting to adapt to the new powersupply. Be careful. If you try to extend the wire length, you may get into trouble. Longer cables will waste power in the length. Also, smaller wire sizes can waste power.
I originally intended to buy only a 80Gbyte unit, but I couldn't find any. At this point, I am more concerned about reformating and repartitioning the 160Gbytes because running a fschk on the huge disk in one partition might take many hours if you consider the amount of RAM and the speed of the CPU. It took about six hours on my Tualitin running in XP with 512mbytes of RAM.
So I am now considering using smaller partitions, like 10Gbytes. If possible, I may even leave half the disk in an unmounted NTFS format to use for backing up my Windows XP machine. Under Linux, I would not touch it. And if any partition is to require fschk on an autoboot, I would even consider much smaller, maybe less than 1Gbyte. Otherwise your boot might take half a day or more.
This leads to two real concerns. [1] What is a good setup for so many partitions and mount points? [2] Also, should one format the disk with a smaller cluster size due to the microprocessor being slower and the RAM being smaller?
Rather than listening for clicks and watching lights, I just put my fingers on the drive and I can feel if it is running and if it is running smoothly. The light appears to have 3 normal modes: bright, dim, and off. When I left the HDD connected overnight, the light was off in the morning. But I was able to have my Xandros Linux machine start it up from sleep mode and read files. The format is still in NTFS as Xandros fortunately is set up to recognize it.
I have an AsusWL500gL [v1] and I am NOT running Kamakaze. Some of your problems may be related to Kamakaze not being properly configured to wake up the HDD. That is why I test this with XP and Xandros. For the WL500gP, I am running Oleg's firmware [1.9.2.7-9] It loaded nicely. But I've yet to do much as I don't want to do a lot of reflashing and brick the unit. I'd prefer to have most of the custom goodies on the HDD where they can be mounted and unmounted without wear and tear of the main unit.
With Linux it is best to read a lot before you do anything creative. Otherwise you just keep reloading the OS when you mess up.
Thanks for all the suggestions Loopy. The power adapter splice job I mentioned in my last post does work. The problems I was having were related to the spin-up errors as you mentioned. Once I realized that the Seagate Freeagent GO had a built-in auto-spundown "feature", I was able to disable it on my ubuntu box with sdparm. Works like a charm now, with only the original 2.5A adapter.
I documented the setup here on my blog: http://whimfield.com/?p=256