External HD questions??

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Steve

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I have just added extra storage to my main rig with a 300GB external HD. This will run of either USB2 or firewire and is independantly powered. I know that firewire is the quickest but as this is purely a backup drive speed is not really an issue, what I am more bothered about is connecting/disconnecting and powering it on and off. I know that USB is hot swappable so that’s no problem but whats the situation with firewire, am I to connect it and disconnect it without the pc being switched on or is it safe some other way?

Any advice please?
 
Yes - Firewire is also hot swappable, if as a precaution (as you should also do with USB devices) you stop the device through the "Safely remove hardware" tab in the system tray then power it down and unplug it, that way you should have no risk of data corruption or disconnecting while its still in use by the system.

For connection just plug it in and power it up.
 
Basically what he said. Power down, then unplug, and the reverse for reconnection, plug in, then power up.

My DV Cam literature and Firewire card strongly advises against, hotswapping live powered devices.
 
Cheers gents, I think I have it sussed now :)

I have now got it connected by firewire (which will always be connected) but I will be powering it on and off at various times while the pc is still powered. I have altered the external drives properties to not cache any files and allow for safe removal without telling windows specifically that way if I was to forget and just powerdown there should be no errors or damage caused. :)

Cheers again.
 
Is it a purchased external hard drive, or an icybox housing with your own HDD installed?

I've been having trouble with the icybox enclosures, ending in all data being lost on the drive. In one case it was 300G of data.
Fortunately I still had copies on the main drives in the PC.

I have two of these enclosures and have had the same problem with both.
Totally lost faith in them. :confused- :banghead: :confused-

Happens when HDD switched on before PC, and off after shutdown.
Also with the safely remove hardware options.

I also have a Frrecom external HDD, and have never had a problem with it.:thumb:
 
Can't USB2.0 run at 480 mbps compared to firewire at 400 mbps? wouldn't it be better going USB2.0 route?
 
Glen said:
Can't USB2.0 run at 480 mbps compared to firewire at 400 mbps? wouldn't it be better going USB2.0 route?
Click to expand...
Not necessarily. reason being, if you have, say for the sake of simplicity, 2 USB2 devices in use at once, you only get 240mbps on each.

By comparison, if you have 2 firewire devices in use at once, you get the full 400mbps on each.
 
Glen said:
Can't USB2.0 run at 480 mbps compared to firewire at 400 mbps? wouldn't it be better going USB2.0 route?
Click to expand...

True USB 2.0 can manage 480Mbps - however FireWire has a much higher sustained transfer rate, whereas USB 2.0 only peaks at 480Mbps.
 
Oh I see..........I'll shut up now then........:getmecoat
 
SATA150 is 'only' 150Mbs so USB2 and Firewire are both probably faster than the drive :D
 
Dont confuse Mbps (Mega bits) with MBs (MegaBytes).

Its takes 8 bits to make 1 byte
 
Actually it usually works out to be 10 bits in a byte, on a serial comms link the protocol overhead adds roughly 2 bits per byte.

I.e. a 512 kBITSps == 50 kBYTESps.
 
SammyC said:
Actually it usually works out to be 10 bits in a byte, on a serial comms link the protocol overhead adds roughly 2 bits per byte.

I.e. a 512 kBITSps == 50 kBYTESps.
Click to expand...
But a byte is and will always be 8 bits, not 10 regardless of 'overhead'. A byte can hold any value between 0 and 255. 0 expressed as binary is %00000000, while 255 is %11111111.

1 = %00000001
2 = %00000010
3 = %00000011
4 = %00000100
5 = %00000101
6 = %00000110
7 = %00000111

...and so on.
 
Agree - it may add 2 bits, but a byte is still 8 bits, just as a nibble is 4, and so on - what your describing sounds to me more like a "word", however Im no expert on serial comms.

However a byte is in most cases - ie networking, performance measurement, always expected to contain 8 bits.
 
Warspite said:
Agree - it may add 2 bits, but a byte is still 8 bits, just as a nibble is 4, and so on - what your describing sounds to me more like a "word", however Im no expert on serial comms.

However a byte is in most cases - ie networking, performance measurement, always expected to contain 8 bits.
Click to expand...
Well, a byte *is* 8 bits. There's really no discussion to be had :) If you need to send 10 bits then you need to be sending a 'word' (2 bytes). But then you're effectively sending 6 redundant bits because you can only transmit whole bytes. I don't wanna get into the realms of bit-shifting/compression to get around that problem, so we should probly go back to the original topic now. :)
 
Im only mentioning word sizes with regard to some older systems which used to handle words that were classed as different sizes.

However PCs (atleast x86 architecture) have always excepted that a word is 16 bits - and yes a byte is always excepted as containing 8 bits.
 
Could i add my problem to this thread as it seems kinda the same

I have a laptop with usb1 and a pcmcia card plugged into side with usb2, i have my external disk in usb1 and it works ok, was showing as G drive andn i labelled it caddy, when i plug things into usb2 ports, they either will not show although lights come on , or completely crash my system. I did get it working yesterday plugging my card reader in but after a reboot back to normal not working mode, is there any compatibilites with having usb1 and usb2 on same machine? (all drivers were loaded the way the instructions said, and all show fine in device manager)
 
Shouldnt be - however if you are running Windows XP you must have Service Pack 1 or higher installed for it to recognize USB 2.0 ports (otherwise it will only show as USB 1.1 and you will get that performance also).

Does the USB 2 PCMCIA card have a power inlet built into it, its possible that it will need additional power for certain devices that USB powered.
 
Warspite said:
Agree - it may add 2 bits, but a byte is still 8 bits, just as a nibble is 4, and so on - what your describing sounds to me more like a "word", however Im no expert on serial comms.

However a byte is in most cases - ie networking, performance measurement, always expected to contain 8 bits.
Click to expand...

Well as an expert of 8 years of serial comms work I can tell you that, yes a byte technically has 8 bits BUT the point I was trying to get across (and failed miserably :D ) is that a guideline of converting from x kBITSps to x kBYTESps is to divide by 10 not 8.

The reason being that BITSps is a raw (inc start/stop bits) bit measure ment whereas BYTESps is a net measurement (not including start/stop bits). Therefore your 1Mbits home ADSL link gives you a peak download speed of around 100 K a second rather than 128 K which divide by 8 gives.

It's nothing special, its just a reality of gross speed compared to net speed.

:)
 
Ha , learn something new every day :). I always thought that as SATA was a serial bus standard the 150M was bits/s and it's not :shock:

27 years as a High-speed Digital Designer and so-called computer 'Standards' can still mislead me :hissyfit:

Just don't get me started on the RS232 'Standard' :banghead:
 
Matt said:
Is it a purchased external hard drive, or an icybox housing with your own HDD installed?

I've been having trouble with the icybox enclosures, ending in all data being lost on the drive. In one case it was 300G of data.
Fortunately I still had copies on the main drives in the PC.

I have two of these enclosures and have had the same problem with both.
Totally lost faith in them. :confused- :banghead: :confused-

Happens when HDD switched on before PC, and off after shutdown.
Also with the safely remove hardware options.

I also have a Frrecom external HDD, and have never had a problem with it.:thumb:
Click to expand...


Yes it is an Icybox and the problem you describe is well documentated. It only effects it if you have the an exclosure that uses a Prolific controller and run it on firewire. If thats the case there is a a firmware upgrade that fixes all the problems :) I just ran it now on mine and it updated with no problems at all, obviously it is too early to confirm if it has solved the issue but as I have not had the issue in the first place I guess I am just playing it safe.

I got the updated firmware from http://www.prolific.com.tw/eng/downloads.asp?ID=44

As I downloaded the latest firmware and the updater (that both run from within windows) and all is well. Make sure you check your existing bios revision first though as you may need to do a two stage update depending on the date. If you are not sure just run the updater and it will give you all the info, then tell it to laod the latest revision firmware, update and then power cycle the enclosure. Once thats done run the updater again and it should tell you that the firmware is at the latest.

HTH
 
Forgot to mention that all firmware checking/updating has to be done through the USB connection not firewire.

If you decide to give it a go Matt and have any issues just give me a shout :)
 
cheers for the link Steve, I'll give it a go and see what happens.
 
Warspite said:
Shouldnt be - however if you are running Windows XP you must have Service Pack 1 or higher installed for it to recognize USB 2.0 ports (otherwise it will only show as USB 1.1 and you will get that performance also).

Does the USB 2 PCMCIA card have a power inlet built into it, its possible that it will need additional power for certain devices that USB powered.
Click to expand...

Thanks pal, i plug my hardrive caddy into the main pc's usb1 it has external power so i assume that is fine, even if i tried it in usb2 port, the pcmcia card has got a small jackplug socket in it, ive just looked, although never got no adaptor with it when i bought it. But, the only thing i do plug into it is a card reader which takes no external power that i see.

Ive just looked in my add/remove programs, and dont see service pack 1 but do appear to have SP2 installed, would that make a difference?

Thanks again for help
 
SP2 should be fine if not better.

In device manager at the bottom of the list should be USB devices.

Are any of these described with Enhanced in their title?
 
hi,

yeah i have one entry saying Standard Enhanced pci to usb controller amongst the usual sis ones which i assume are the onboard ones.

Just checked properties of it and no conflicts, driver seems fine. so no issues reported

Ive also plugged in my external drive in its caddy with the external power, it shows a mass storage device being on now and no conflicts there but i see nothing in my computer for it
 
See if there is an updated driver for your PCMIA card.
 
Thanks Sammy, im wondering if my issue is perhaps not usb, its all working, and under drives in hardrives in deviice manager it shows as a usb driive, but i cant seem to find it on pc, it has not been assigned a drive letter in "my computer" so no idea what now.
 
In that case you need to go into Administrative Tools in the Control Panel, from here you want Computer Management, then Disk Management.

Then you should be presented with a list of hard drives currently running, select the removable drive (assuming its there) and right click, then select format. - Only do this if the drive has not been formatted already. If it has been formatted already it should have either NTFS or FAT, FAT32 to indicate what file system its using, and it should also have been assigned a drive letter.
 
just checked that, it doesnt show although i did notice a extra dvd drive???? i uninstalled the driver for it and it reloaded itself back in.
 
Have you tried the Add Hardware Wizard, see if that detects anything new?
 
Yeah just tried that thanks, it doesnt find anything, there is an entry for "usb device" which i iclick on and it says its works properly as well as an entry for " mass storage" which also says working properly.

So to cap, it shows in device manager as mass storage, it shows in device manager under disk drives as usb device next to main hard drive ( both times it says its working correctly), under disk management i have my drive, my partition and cd rom, and a dvd rom that shows even when i uninstall it and rescan drives.
 
I take it you don't have a dvd-rom then?
 
Whats the manufacturer, model , any other details of this USB drive?
 
Sammy, no i dont pal, i get rid of it by removing it in disk management but it shows again on reboot.

Its a maxtor 80 gig hard drive plugged into a caddy that initially housed a dvd player, but ive had the hard drive in for ages now, in the usb 1 it immedietly when switched on shows as G drive and i can access pics etc

The caddy thing itself i have no idea what make it is, if that matters.
 
Can you recall if the hard disk is configured as Master, Slave, or Cable Select (CS)?

Also what other devices are connected,

Hard Drive (system)
Optical Drive?
Pen Drives?
etc?
 
Well its not much help but XP SP2 does have some issues with USB2. I thought it was mainly restricted to VIA chipset boards but maybe not.
 
Thanks for this, i had all the details but the site appeared to go down,

ive made some headway now.

With it all running and not showing, i decided to uninstall the enhanced controller, but left everything plugged in, when i did this, xp found the hardrive by name and it gave it a drive letter, could access it, but a small box said that this would run faster on usb2, so i assume it reverted back to usb 1.

Then i decided to reboot, when i did this and windows started, its found new hardware, and reinstalls the mass storage devices etc and back to square 1, showing the mass storage device but nothing listed. Uninstall the enhanced driver andn immedietly i get the drive showing and the not usb2 warning.

2 steps forward, 3 steps back, is there a way to stop windows finding the new device at startup, if the drive is only running at usb1 that would do me, at least i can access it, id just rather it not find it again on reboot and install diff drivers. usb1 is better than it not working, unless this is a common fault

And Thanks guys for all this help, ive had it 1 year now and never yet got everything working.
 
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