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iMac Harddrive help please

JoshBoy

JoshBoy

macrumors 6502
Original poster
Oct 12, 2008
490
366
Sydney, Australia
Hi everyone,

I have an iMac that decided to crap itself (the harddrive) and it is so expensive to get a new hard drive placed in it. I know I could do it myself but I just dont want anything more to go wrong.
If I was to link a external harddrive to it and install SL on that and continue to use the external as the primary drive would it be slower? What about USB 2.0 compared to firewire?

Any help on this would be great.

thanks
 
just to add

Also just to add is I have the imac listed above and have had it from end of 2007 / start of 2008 (ordered Novemeber 07 but received Jan 08) so I am assuming that it has firewire 800 on it
 
also just to add even more to it is I have thought about data transfer speeds, now the speed on USB 2.0 is 400meg per second, firewire 800 is 800 meg per second, SATA is either 3Gps or 6Gps. When i looked at the top line HDD from seagate it offered the following specs on a 64meg cache and 6Gps SATA -
PERFORMANCE
Spin Speed 7200 RPM
Sustained data transfer rate 138Mb/s
Average latency 4.16ms
Random read seek time 8.5ms
Random write seek time 9.5ms
I/O data transfer rate 600MB/s
Unrecoverable read errors 1 in 1014

If the sustained data transfer rate is under 400 or 800 meg per second you would notice a change would you? The HDD can only go as fast as a max 600????

Any help once again would be great.
Cheers
 
Firewall 800 isn't 800 megabytes/s it's 800 megabits/s which is 100 megabytes/s. Just like the 3Gbps, it's gigabits not gigabytes. I don't think you'll get any benefit from a 6Gbps drive.

You'd notice a huge slow down using a drive externally I think, you'd need to have it internal.
 
Hello.

Yes, you can boot from an external Firewire drive.
FW shouldn't cost you much speed, especially FW800.

USB2.0 is much, much slower than even FW400. Also, you may not be able to boot from it anyway.
"But why is USB2.0 rated faster than FW400?" you ask?
FALSE ADVERTISING, that's why!

Just get a FW800 external drive if you've got doubts about opening up your iMac.

BTW, I know the white iMacs are quite easy to open for drive access.. Probably the aluminum ones are too.

Good Luck,
Keri
 
KeriJane said:
Hello.

Yes, you can boot from an external Firewire drive.
FW shouldn't cost you much speed, especially FW800.

USB2.0 is much, much slower than even FW400. Also, you may not be able to boot from it anyway.
"But why is USB2.0 rated faster than FW400?" you ask?
FALSE ADVERTISING, that's why!

Just get a FW800 external drive if you've got doubts about opening up your iMac.

BTW, I know the white iMacs are quite easy to open for drive access.. Probably the aluminum ones are too.

Good Luck,
Keri
Click to expand...

Thanks for that. It is not the white one it is the aluminum one.

I am really concerned with speed loss on it. I can see that firewire 800 external would be the best option for that I just wish i could real life test it all.
 
Difference between fw800 and internal SATA is mostly drive speed dependent. In theory FW800 can perform up to 100 MB/s, in practice it rarily exceeds 80 MB/s. So if your drive can perform more than 80 MB/s (such as Samsung F3 HD502HJ for example) it will be a little choked with FW800.
 
666sheep said:
Difference between fw800 and internal SATA is mostly drive speed dependent. In theory FW800 can perform up to 100 MB/s, in practice it rarily exceeds 80 MB/s. So if your drive can perform more than 80 MB/s (such as Samsung F3 HD502HJ for example) it will be a little choked with FW800.
Click to expand...

What do most drives run at?
 
I am close to actually ripping the drive out myself i think. I use the iMac for photo and video so speed does matter. I noticed that some drive write at around 90 - 100 MPS, with firewire 800 that should be able to handle it but there is the chance it wont. Oh the confusion :eek:
 
There's no doubt you'll have a slower computer by working off an external HD, regardless of it being FW400 or 800. Don't go with USB since that'll be painfully slow. But I'd definitely recommend you plan to replace the hard drive as soon as you can.

I assume you don't have AppleCare.

Replacing the HD is not too difficult. I used to have the exact same model, and did some basic maintenance on it without too much trouble. You do need the suction cups for the glass cover and a anti-static wrist band and mat... and also be very careful when taking the glass off. Take a look here.

Cheers!
 
diazj3 said:
There's no doubt you'll have a slower computer by working off an external HD, regardless of it being FW400 or 800. Don't go with USB since that'll be painfully slow. But I'd definitely recommend you plan to replace the hard drive as soon as you can.

I assume you don't have AppleCare.

Replacing the HD is not too difficult. I used to have the exact same model, and did some basic maintenance on it without too much trouble. You do need the suction cups for the glass cover and a anti-static wrist band and mat... and also be very careful when taking the glass off. Take a look here.

Cheers!
Click to expand...

I bought a HDD today to place in the iMac, the tools I need plus some compressed air. I dont have an anti static mat or wrist band, is it really needed? I have no carpet floors in my house at all and will be working on a glass benchtop or a rubber floor, will that be ok?

I use to build computers all the time (in my PC days ) and never used an antistatic band?
 
JoshBoy said:
I bought a HDD today to place in the iMac, the tools I need plus some compressed air. I dont have an anti static mat or wrist band, is it really needed? I have no carpet floors in my house at all and will be working on a glass benchtop or a rubber floor, will that be ok?

I use to build computers all the time (in my PC days ) and never used an antistatic band?
Click to expand...

I'd say yes, it's safer - static energy also comes from our bodies too. But some would say that it's OK as long as you discharge yourself by touching a grounded pipe or surface, and don't touch any other electronics inside, which are traditionally very sensitive to static discharges - such as the CPU / GPU units. Anyways...

Good luck!
 
diazj3 said:
I'd say yes, it's safer - static energy also comes from our bodies too. But some would say that it's OK as long as you discharge yourself by touching a grounded pipe or surface, and don't touch any other electronics inside, which are traditionally very sensitive to static discharges - such as the CPU / GPU units. Anyways...

Good luck!
Click to expand...

Well everyone I now have the HDD in the iMac, thank you everyone for your help and advise. iMac is bigger and better than ever. :)
 
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