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Hans M Aus · Jan 28, 2009, 03:56 PM

disk1: wdc wd800bd 40m ra1 74,5gb.
disk2: wdc wd1600js 40tg b0 149,1gb.

4 identical iMacs with OSX 10.4.11; 3 with disk1 and one with disk2.
All four systems have about 28 GB on the disks.

I'm helping a friend understand why the iMac with the bigger disk2 boots much slower than the 3 iMacs with the smaller (GB) disk.

I've run the following tests:
Disk Utility.
Whatsize (didn't find any unusual blocks of files.
Yasu - I used the standard options, which doesn't clear the fonts etc.
Disk Warrior.
TechTools Pro.

Nothing made any significant difference in the startup speed on disk2.
Any ideas what else could I try?

Big Mac · Jan 28, 2009, 05:37 PM

How much slower?

Hans M Aus · Jan 29, 2009, 03:29 AM

Startup takes about a minute on the slower iMac.

P · Jan 29, 2009, 04:13 AM

I wouldn't bother, but then I rarely shutdown my Mac. Sleep mode every time.

More RAM means a longer boot time, as the RAM has to be tested. Slower (access time) HDs and smaller cache also tends to add time to the startup.

Finally, check that the startup drive is selected in System Preferences. If no drive is selected, it still works but is slower as the system scans existing drives for possibilities to boot from.

Hans M Aus · 04:43 AM

Originally Posted by P

...
More RAM means a longer boot time, as the RAM has to be tested. Slower (access time) HDs and smaller cache also tends to add time to the startup.

Finally, check that the startup drive is selected in System Preferences. If no drive is selected, it still works but is slower as the system scans existing drives for possibilities to boot from.

All four iMacs have 1GB RAM.
Where can I find information about the disk access time and cache size?
I'll check the startup drive selection in the System Preferences - thanks for the suggestion.

I have the impression that MacOSX is searching (scanning) for something. The long delay is the gray screen before the MacOSX startup window appears. Afterwards, the startup proceeds fast.

tooki · Jan 29, 2009, 06:18 AM

What part of the gray screen are we talking about?

There's (1) the startup chime and initial appearance of the blank gray, then (2) the appearance of the apple logo, then (3) the appearance of the gray spinner, and finally (4) the appearance of the blue background and loading of the welcome screen, then Finder, etc.

Telling me which stage is taking longer tells me exactly what component of the boot process is stuck, and potentially how to fix it. But based on even just knowing "gray screen", my hunch is that disk performance is not the issue at all.

FYI, the cache size does NOT make any difference, as people think. It just doesn't. It did help back when cache sizes were below a MB, but performance differences between 8, 16 or 32MB cache are statistically insignificant, both in real-world use and in benchmarks.

Moreover, remember that hard disk caches are used mostly to improve write performance, while most hard disk activity during startup, application launches, file opens, etc. is multiple small reads.

P · Jan 29, 2009, 07:39 AM

Originally Posted by Hans M Aus

I have the impression that MacOSX is searching (scanning) for something. The long delay is the gray screen before the MacOSX startup window appears. Afterwards, the startup proceeds fast.

Then it's probably the other think I suggested: Go to System Preferences -> Startup Disk and select your main HD as the startup disk. Reboot and see if that fixes it.

Simon · Jan 29, 2009, 08:27 AM

If selecting a startup disk isn't the cause (which I'd guess it is), you can boot into verbose mode (boot holding cmd-v) to see what is causing the lag.

Hans M Aus · Feb 2, 2009, 08:11 AM

Thanks for the informative help so far.

The startup disk is selected and the elapsed times are:

1) From start chime till gray logo: 34.5 s.
2) From gray logo to spinner: 2 s
3) From gray spinner to welcome window: 2s

Shut down is also slow.

P · Feb 2, 2009, 12:30 PM

Hmm. Could be a bad PRAM battery, but it seems like a longshot. Odd.

ibook_steve · Feb 2, 2009, 12:42 PM

Originally Posted by Hans M Aus

Thanks for the informative help so far.

The startup disk is selected and the elapsed times are:

1) From start chime till gray logo: 34.5 s.
2) From gray logo to spinner: 2 s
3) From gray spinner to welcome window: 2s

Shut down is also slow.

I'm confused. These times add up to less than a minute. How fast are you expecting the machine to boot and shut down and why is this such a big deal? Now if this was a machine with an SSD, I might be concerned, but this is still pretty fast.

Boot from an install CD and try repairing the disk as well.

Steve

Hans M Aus · Feb 2, 2009, 01:13 PM

It's considerably slower than the other 3 iMacs in the same room.

ibook_steve · Feb 2, 2009, 05:50 PM

So you can boot 3 of your iMacs in like, less than 30 seconds, and this one is taking more than 30 seconds, about a minute as you say. And this is a problem? If you must, start up in verbose mode (hold cmd-v, I believe) and watch the boot process to see what might be holding it up. If I were you, though, I'd be very happy with these boot times and not worry about it.

Steve

Simon · Feb 3, 2009, 03:30 AM

The OP is curious, that's ok.

But I already suggested verbose mode to find out what's holding up the boot a few days ago and the OP still hasn't reported any results.