By Graham K. Rogers

Last week Apple moved the goalposts again, slightly, with the release of an entry-level iMac with 21.5" display. While it shares many of the components and specifications of the current range, there are at least two major differences: the dual-core 1.4 GHz processor, that runs slower than the other iMacs; and the LPDDR3 memory.

This fast memory cannot be upgraded but 8 GB should be enough for basic use. Like other new Macs, the fully-integrated construction of the main board means that repairs are almost impossible.

Some of the components, particularly the memory, appear to have been developed for smaller devices and it is interesting that they have found their way here.

The market appears to be home users who do not have a need for speed: after all, many are quite happy with the MacBook Air that runs the same chip. It could also be useful in offices that have little use for high-level graphics processing, and in some schools.

The price here is 37,900 baht which is slightly cheaper than the US price of $1090 when 7% VAT is factored in.

Someone I know recently upgraded to Mavericks and complained that iTunes was crashing a lot. As this needs online access for the best results, some problems may be due to poor internet connections. There are also data-related problems; but it may be that the installation has faults.

It would be wrong to think that Macs are fireproof: that they shrug off any amount of abuse. I don't often have things go wrong with mine. I am careful what I install, run maintenance every once in a while and back up my data at least once a day.

Occasionally, an application decides not to cooperate. I may quit, or even Force Quit if there is no change. Sometimes, an app may crash: usually indicated by a panel offering to send a report to Apple. I always allow this.

Any update will put more pressure on a system. I asked if he had checked the disk before installing Mavericks. He said he had: using Disk Utility. Nothing was wrong.

I thought about this for a day or so and asked, "How?" because a proper check of the disk can only be made if it is unmounted: you cannot check or repair a disk you have started from. All you can do with Disk Utility is Verify. He had not even done that.

He had looked at the S.M.A.R.T. Utility (Self-Monitoring, Analysis and Reporting Technology) and that had reported OK. When I asked about checking the OS X installation itself, that had not been done. I think that was a major error as the integrity of the operating system and related files is more likely to affect an update.

I use Disk Utility to give me an idea if there is something significantly wrong. If I am about to update OS X, I run Disk Warrior. He winced when I mentioned the price of $99.95 (3250 baht) and he is not alone, but what is the cost of a new disk; and what value is your data? My hundred dollar investment has paid me back many times, including when a hard disk did fail and I was able to use Disk Warrior to recover all of its data.

Recent versions of OS X have a Rescue partition which does away with the need to use external media, such as a disk, flash drive or second Mac. This is still needed if Disk Warrior or other 3rd party repair utilities are used.

I asked him if he knew how to access the Rescue partition. There was a look that can be best described as "deer in headlights." Since OS X 10.7, Lion, Macs have had a section of the disk set aside with some tools to help recovery in many circumstances.

This is accessed by starting the computer while pressing the Command + R keys together. With this a user may install a new copy of OS X, use a Time Machine backup, and access some utilities. The main OS X partition can be repaired from here with the version of Disk Utility installed.

Many users go through their Mac-owning lives without ever running proper maintenance, with the thought (sometimes defended quite strongly) that there is nothing wrong with their computers. There are those who never check the oil in their cars, trusting to the regular service intervals, who are surprised when the car makes odd noises. You can no more see into an engine block than you can see inside an operating system. Trust or faith are not valid maintenance regimens.

I run maintenance checks at least once every 3 months. Sometimes minor problems are fixed, but one bit of data wrongly written could be the start of a problem and you would never know until it was too late.

See Also

• iMacs at Apple Store Thailand
• AnandTech on Apple's new entry-level iMac (Brandon Chester)
• Mid-2014 iMac review: lower price, way lower performance (James Galbraith, MacWorld)
• Alsoft Disk Warrior

Graham K. Rogers teaches at the Faculty of Engineering, Mahidol University in Thailand where he is also Assistant Dean. He wrote in the Bangkok Post, Database supplement on IT subjects. For the last seven years of Database he wrote a column on Apple and Macs. He is now continuing that in the Bangkok Post supplement, Life.