Home Forums Hardware Mac Desktops & Notebooks Wonky startup and freezes (iMac)

Latest chapter in the saga:

Tech reports that, following installation of new Seagate drive, fans run at higher speed such that the iMac is intolerably noisy. This is likely due to the proprietary firmware in the Apple-commissioned hard drives. (The tech could try out any number of third-party hard drives to see if he could find one that would work properly, but he'd have to charge for the time and effort, with no guarantee that there would be a successful outcome.)

So now the only option is to go to Apple and acquire their officially sanctioned drive (500 GB, SATA, 3.5", 7200 rpm). The major downsides are the cost (3x what the other drive runs), a lousy 90-day warranty (instead of 3 years), and currently a lack of a hard drive in the Apple system (meaning at least a couple weeks' delay in getting my iMac back).

Are we having fun yet?!

Apple's chutzpah is much as it's always been, now coming up on the 30th anniversary of the introduction of the Mac. But what can you do when PCs suck? This is the first major hardware problem I've had with a Mac over 3 decades. So, I guess I've just got to keep a stiff upper lip and bite the bullet.

Nope! (or at least, not likely)

We replace dozens of hard drives a month here. A typical mac has between 7 and 24 temperature sensors in it, most of which are discrete. A few are included in other hardware, such as the die temp on a processor, or the SMART temp reading on a hard drive, or the hard drive temp sensor pins themselves on the back connector.

This allows the mac to zone-control fan speeds, so for example you get more cooling to the optical drive area while burning a disc, without speeding up other fans, or running any fan faster (and louder) than necessary.

In the event that the SMC loses contact with a sensor, gets out-of-range data, or detects some other sensor problems, the sensor is ignored until reboot. During that time, the fan in that zone, or possibly all zones, will be run up to max speed to protect the hardware.

Many hdd manufacturers now include breakout pins on the backs of the desktop sata drives, so the computer can get a direct tap on the temperature of the drive, instead of having to poll SMART or stick a sensor to the enclosure.

Using this connector requires the correct cable, correct wiring, and also the correct baseline information on the kind of reading the sensor is taking. (is that one millivolt per degree, or one microvolt? celsius or farenheight? what's zero degrees?)

When you replace the hard drive with a different model, there's a good chance it uses different baseline information, or a different connector altogether. Some shops will tell you that Apple is doing something "proprietary". They're not, they're just working with Seagate or Western Digital or whoever, according to their specs, and taking advantage of their published product features.

They'll either do this to you out of ignorance of how it works, or that they either don't know how to work around it, or don't want to bother with it.

There are several correct approaches. First is to obtain the correct cable, or modify the existing cable to attach to the new drive. Probe the pins on the different connector and find the correct pair. And hope the baseline information is close enough.

If the pins cannot be correctly matched, or the baseline is too far off, you cannot use the new hdd's temp sensor. The SMC will not be amused when you unplug it. You can sometimes take the OBCC card off the old hdd and sneak it in behind the optical drive and plug it in and keep the SMC happy. Works well with the older imacs.

Or you can try to cobble something up from radio shack, sometimes a discrete transistor junction works fine.

Or you can get online and find some more "universal" temp adapters made expressly for this purpose. They allow you to configure proper baseline info and provide useful temp data without the drive being involved at all.

Finally, you can buy HDD Fan Control, a piece of software designed expressly for this problem. It tells the SMC to ignore the issue. It will also allow you to override fan speeds by directly controlling them in leu of the SMC, to set new low speeds, etc. Handy app. I think it also allows you to feed the hard drive's SMART polling to the SMC instead.

so... don't blame Apple for this one.

Thanks for the info.

I've got to work with what I've got in these here parts. So let it be said, so let it be done. Sadly.

Would it pay to try the same brand HDD as shipped with grelber's iMac, or is the difference more likely to be a proprietary Apple thing that would call for the exact same HDD rather than just the same brand?

Good reply, but it responds to my statement up to the comma, rather than the part afterwards...its crux.

I simply suggested that Time Machine is Apple's backdoor out of grelber's situation, i.e. that not having a high-speed Internet connection does not leave you in a bind with no way out...that unaffordable Internet can be overcome with a low-cost external external HDD loaded with Recovery Assistant and Time Machine backups.

I still say no.

Apple stopped supplying the OS on optical media with OS X 10.7.0. They didn't make Time Machine backups bootable until 10.7.2. If TM were part of the justification, TM backups would have been bootable from the get-go.

I think Apple thought "unavailability of high-speed internet" was a non-issue.

a) Most users have high-speed internet to their home or office.
b) Most of the remaining users have a friend or neighbor with high-speed internet access.
c) In a pinch, you'll visit an Apple Store, or take your computer to a computer repair technician, both of which have high-speed internet access.

In short, Apple probably considers that those complaining they don't have high-speed internet really mean they don't have high-speed internet to their home, which is not actually the same thing.

In the meantime, the benefits of internet-only software delivery are so significant that they greatly out-weigh the "convenience" of having installation DVDs that everyone promptly loses anyway. Nobody ever forgets where they put their internet.

The rare person who really can't get high-speed internet can obtain installers on other media (flash drives, for example). These other media are priced so as to make people consider carefully whether they really truly don't have access to fast internet, or is it just that such access is inconvenient.

The cost equation is: saving millions of users several dollars apiece justifies making a small handful of users have to pay a little more.

Notice that Time Machine is never mentioned anywhere in that evaluation.

I was unaware of the 10.7.0/10.7.2 thing; you're obviously correct about its effect on my argument.

You seem to think that I'm arguing for distribution of install discs with all newly shipped Macs, but I'm not and never have. I fully understand the factors that led to Apple's decision to discontinue discs, and my only argument has been that they were remiss in not having put a program in place to accommodate people like grelber, rather than advising them to be "schnorrers". (As you've read, grelber has no access to high-speed Internet, and tech-installed OS X would have cost him $100; luckily, he was able to schnor a recovery partition, but not everybody in a similar position is that lucky.)

Lion was available on an Apple-produced thumb drive, but Mounty has never been issued in that format, nor, apparently, will Mavericks or any further version of OS X be issued in that format; the "installers on other media" you're touting, with the exception of those Lion drives, are, and will forevermore apparently be, pirated software.

Not exactly schnorring, re Recovery Disk Assistant.

The app is available via Apple ... and has been for a long time. I'm surprised that no one mentioned it when we were having the l o n g drawn-out discussion apropos system reinstallation back in late 2011 — and even more recently via discussion with Apple Care reps. It's a relatively ideal solution as long as one has Time Machine backups; it also obviates the necessity for cloning the drive and eliminates repeatedly cloning to keep things up to date.

There are 2 caveats which accompany RDA's creation and use:
(1) If the computer shipped with OS X Lion or Mountain Lion, the external recovery drive may only be used with the system that created it.
(2) If the system was upgraded to Lion or Mountain Lion purchased from the App Store, the external recovery drive can be used with other similarly-upgraded systems.

Had I known the app existed, I would have created an RDA for myself long ago but been constrained by caveat (1) – no biggie. Since I didn't, my RDA, created as described in caveat (2), can be used on any machine – a fair benefit.

Now all that remains is for me to get my iMac back in functioning condition so that I can find out if the RDA actually works and restores my system via Time Machine to its status at the time of collapse.

And this just occurred to me... It's only a guess, but bootable Time Machine backups seems too momentous to have come in an incremental update, and it's altogether possible that Apple's intentions were that it be included in Lion from the get-go (Edit: It would have made TM a complete package.), but they couldn't get it right until 10.7.2.

Schnorring only in the sense that you weren't aware of the RDA app when you created your Recovery Disk from your colleague's Mac.

I guess the only piece missing from the puzzle is an Apple doc that pulls together all the pieces for people in your situation...lays out all the available options. (Perhaps it exists, but I've never seen a link to it.)

$400+ later and my iMac has returned.

Recovery Disk Assistant employed which then restored my hard drive and recovered my last session on 09-24 from Time Machine. The recovery took 67 minutes (the first 50% took 50 min, the second 50% took only 17 min), but I only had ca 40GB to recover. So far, so good.
The only apparent downside is that backing up after doing all that is taking a honkin' great amount of time.