5400rpm external drive with 7200rpm iMac?

Hi folks,

I just purchased my first iMac (2.7GHz Intel Quad Core with 7200rpm drive). I have an external LaCie rugged drive that's 5400rpm which has a bunch of my data. If I use it with my iMac, can I expect normal performance of a 5400rpm drive? I'm asking because a few times now the computer has slowed down to a standstill, with the beach ball icon showing up, and nothing happens at all. The mouse pointer moves (although on occasion that freezes up briefly too), but that's it.

Just wondering if something's wrong with the external drive, or if this mix-match between rpms can cause this issue.

Meanwhile I'll try checking the external drive on another 5400rpm machine to be certain.

Thanks!

How is it attached? If it's not Thunderbolt, it's gonna be slower than your internal drive.


That said, I have intermixed speed drives and have no such issues. I did, however, have some issues with the new iMac when I got it.. and it ended up being replaced.

It's connected with a FireWire 800 cable. I can understand it being slower than the internal drive of course, and I assumed everything would default to a 5400rpm speed. However, this seems to pretty much stall.

I should also mention that the iMac is refurbished. Hopefully it's not an issue with the iMac. I'll test the external drive on another machine and post results.

If you continue having issues, and it tests fine on the other Mac, call Apple. They'll likely have you reset SMC, PRAM, and maybe even reinstall Lion fresh.

So I tried using the external HDD on my Macbook again - worked just fine with no issues. Tried using it on the iMac - same issues. Tried connecting with USB2.0 instead of FW800 - same issues. Tried backing up and reformatting the external HDD, but to no avail. It also seems like even when the external HDD is disconnected, other bus connected devices like my audio interface etc. make the system ridiculously slow to the point of not being able to use it.

BTW, I talked to Apple support and yes, they did make me do SMC and PRAM reset. In the end we thought that the LaCie HDD had to be updated for drivers, but after trying that it didn't work. Of course, by then the offices were closed.

I should also mention that this is a refurbished machine with full warranty etc. I have an appointment set up at the local Apple store for Wednesday, but if it's truly an issue with the machine and not something silly, I am not comfortable with having a refurbished machine refurbished again! I want them to replace it with a new one.

Thoughts or advice?

Well, my iMac had similar issues. Brand new, retail packaging. It happens. Everyone has a DOA product from time to time (even refurbished). That said, I was in and out within a half hour of my appointment time, with a brand new replacement. I suspect they'll take care of you.

Yup, confirmed DOA. After 3 days of pulling out my hair, talking to three different Apple advisers and posting on all kinds of forums, I lost patience and decided to do a clean install. Same issue even without installing or connecting any third party program or external device. I have an appointment with the Genius bar tomorrow and they'd better give me a new machine.

Yes - glad you found a solution. WHile the external drive will be slower than your internal - due to the interface more than the rotating speed - there's no issue with 'compatibility' between the two. Hope you're up and running soon.