A question about powering down hot-swappable ext HD's
I've always worried if I am doing it wrong or is there a "right" way to do it. Specifically for USB2/firewire HD's, is it better to pull the AC plug at the wall wart or to pull the DC power line at the jack on the HD case? Is one way harder on the electronics that the other? (naturally, the HD is unmounted from the desktop before powering-down)
At first I reasoned that pulling the AC plug might cause a power surge which potentially could zap the HD through the DC line. So I figured pulling the DC power line at the jack on the HD would be safer for a quick cut of power. OTOH, I've noticed that the power-on LED on the external power supply dims out slowly after I pull the AC plug. So maybe this suggests the power supply has a soft-power down mode to decouple the DC line from any nasty power transients when you pull the AC plug. That said, maybe that is more preferable than simply pulling the DC line at the jack on the HD case.
What's your take on it? (...and yes, I've had a HD fail on me just recently. Maybe it was just coincidence timing or maybe my disconnecting preferences actually made a difference?)
At first I reasoned that pulling the AC plug might cause a power surge which potentially could zap the HD through the DC line. So I figured pulling the DC power line at the jack on the HD would be safer for a quick cut of power. OTOH, I've noticed that the power-on LED on the external power supply dims out slowly after I pull the AC plug. So maybe this suggests the power supply has a soft-power down mode to decouple the DC line from any nasty power transients when you pull the AC plug. That said, maybe that is more preferable than simply pulling the DC line at the jack on the HD case.
What's your take on it? (...and yes, I've had a HD fail on me just recently. Maybe it was just coincidence timing or maybe my disconnecting preferences actually made a difference?)
Comments
So I wonder what does your typical power switch do on an external HD? Does it cut power at the AC or at the DC?
Originally posted by Randycat99
Naw, my setup is ghetto-style. It's just an IDE/USB adapter cable and an external power plug.
So I wonder what does your typical power switch do on an external HD? Does it cut power at the AC or at the DC?
Doesn't matter unless your PSU is totally crappy
<SATA SALES PITCH>After working with firewire bridgeboards for so long, I can honestly say that firewire sucks for hard drives. It knocks down speed and takes up a bus that could be used for something useful like an iPod, external device (like an eyeTV200), or a digital camera (or all 3 in my case).
External HDD's via firewire are flakey, slower, and a total waste of money.
I'd highy recommend using external SATA, there's this company called firmtek that offers a few great cards, one of which I installed.
After you buy the SATA PCI card, you can simply connect the PCI directly to any SATA hard drive via a cable. There's no adapter needed, but sheilded SATA cables are about $13 for 1 meter AFAIK (same as "good" firewire cables).
Each drive has it's own bus, and there's NO TRANSITIONAL SPEED LOSS because you're going directly from native SATA PCI to native SATA HDD.
When good Firewire bridgeboards are slower and more expensive than more reliable SATA controllers, why would you buy anything else?
Think SATA.
</SATA SALES PITCH>
But I was also buying new, SATA drives at the time, and I already owned an enclosure.
The fixed costs for you are probably way too high.
If I ever need more drives, I'm just going to upgrade my SATA card and buy a cheap PC case with PSU.
don't worry, randycat, i also have a drive hooked up using a card adaptor that also had an ide cable adaptor. i suppose i should be worry the same way as you, but it's only a backup drive which i hope to sell soon.
Originally posted by jonnyboy
so are usb2 ext hdd's ok?
don't worry, randycat, i also have a drive hooked up using a card adaptor that also had an ide cable adaptor. i suppose i should be worry the same way as you, but it's only a backup drive which i hope to sell soon.
USB is worse than firewire. Though USB2 is 480mbit, it still is non-native to all drives (like firewire), but has the added disadvantage of not being able to sustain its throughput at a given rate for more than a few thousand kbits, and it can be jumpy sometimes.
It's kind of like network drives--it'd be OK for backing up stuff (like firewire is), but for every day use and especially booting, even firewire has it beat, and firewire loses ground to any and all modern native media, like SCSI, SATA, UDMA, etc.
well i only want one of those 250/300gig behemoths for mass storage, not strictly everyday use so i think i'll be fine.
Originally posted by slughead
External HDD's via firewire are flakey, slower, and a total waste of money.
I agree with a lot of the other things you said (sorry i snipped them), but external firewire drives, especially FW800, are very useful for permanent back ups of project files. I'm also a huge fan of sata, but when it comes down to it, i dont sleep at night unless my portfolio lives on a drive completely separate from my system. you just never know what will happen. So while they do have their limitations, FW drives do have a use.
Also, as far as powering down and stuff, I've never had problems hot-swapping, but i dont normally do it. On the other hand, I have seen A LOT of firewire drives get fried, mostly on PC's (coincidence?)
Originally posted by ipodandimac
Also, as far as powering down and stuff, I've never had problems hot-swapping, but i dont normally do it. On the other hand, I have seen A LOT of firewire drives get fried, mostly on PC's (coincidence?)
Panther has this automated de-frag thingus that goes through and defrags stuff. There used to be a problem where firewire drives wouldn't quite defrag properly and data corruption occured in the FATable. They theoretically fixed it, but that's where the flakiness argument comes from.
For backup, as I said before, they're fine. But since firewire was initially advertised as something multiple computers could boot off of at once...
And btw, firewire is much slower on G5s than G4s, according to http://barefeats.com