11 Replies Latest reply: May 30, 2011 7:44 AM by WZZZ
gangof4 Level 1 Level 1 (15 points)

I just purchased this month the 22 inch iMac with the new quad core and aThunderbolt USB.  Can I reasonably expect a good five years of regular use (3-4 hours a day?) without a drop in performance (and keeping in mind whatever upgrade potential the iMac has?)  What's the worst thing I can do to decrease its longevity (short of tosing it in the bathtub?)  What's are the best things I can do to prolong it's performance?

iMac, Mac OS X (10.6.7)
  • John Kitchen Level 3 Level 3 (645 points)

    With basically decent treatment, it should still be operating well after 5 years.  HDDs may give trouble, but they can be replaced.


    To prolong its life, power it from a UPS to protect it from lightning-induced and other surges and keep it running during short outages.


    To maintain performance, never allow the HDD to fill up beyond a certain level.  What's a "certain level"?  Some say as low as 70%, others say higher.  If the HDD does fail, replace it with the largest capacity HDD you can get, no matter how much data you plan to put on it.  If the HDD capacity is very underutilized, you'll get super performance since the data will occupy only the outer cylinders of the HDD, the seek time will be much reduced, and the data will be on the densest tracks.


    When you add disk drives to the Thunderbolt connection, use the same principle as above.  Also consider getting external HDDs which spin faster.  Thunderbolt is fast at transferring data, but when a disk access is moving the heads or waiting for the correct rotational position, there is no data to transfer!


    Make sure you add sufficient RAM to ensure that the number of page outs (see Activity Monitor) is way, way less than page ins.  RAM is cheap (in 4GB modules), and you can never have too much.  Your iMac will support up to 32GBs, using 8GB modules, but the price of these needs to, and will, drop.  Right now, it's very affordable to upgrade to 16GBs.


    Look for discussion threads on maintenance tasks such as repairing permissions.  If your Mac is slowing down, it will usually be because the file system on the HDD needs some attention.  That's a whole big subject on its own.

  • WZZZ Level 6 Level 6 (12,695 points)

    There is no minimum life expectancy. I think the single most important thing you can do is to keep the computer running as cool as possible. Too much heat, long term, kills hardware. That said, the hard drive will die. Not a question of if, but when. So, make sure you have a backup. My preference is for a bootable clone on an external drive, from which if the internal drive dies, you can go right on working. There is also Time Machine. Some have both. Bear in mind also, that the PRAM (clock) battery -- usually a common CR2032 -- has around a five year life expectancy. It is deeply buried in the computer. After about five years Apple considers any Mac obsolete and won't work on it. You will then have to go to an Apple Authorized repair.


    Get iStat Pro or Temperature Monitor. They are both free.


    You will find a difference of opinion on this, but I use smcFan Control to manually ramp up the fan speeds. Many find that the system does not react to heat quickly enough. (Disregard anyone who tells you that your Mac will shut down by itself if it gets dangerously hot. This is true, but you want to avoid the kind of overheating that won't trigger a thermal shutdown.)


    The way I use smcFan is to create four or five settings, not including the defaults, in increments of about 15% up to around 2K. To avoid burning up the fan motors, I use the minimum setting possible. Here is a thread with some temps, to get a very rough idea of the temps you may be looking for. In the winter, I run it at the defaults or just a few hundred rpm above. In summer, I go a bit higher.




    I may also run a small fan aimed at the upper left of the back as you face the screen, the hottest area of the case. The aluminum back acts as a heatsink and keeping it cool will help to dissipate the internal heat.


    With the computer shut down, periodically vacuum out the intake grilles at the bottom and behind the stand. This is where dust accumulates and restricts the air flow.




    EDIT: Repairing Permissions is generally given as a step to resolve almost any problem. There are specific times to do that, but as general advice, that recommendation is pure voodoo, and a waste of time.


    EDIT: Keep around 15-20% of the available drive space free. That said, I don't think this is linear. e.g. if a drive is 2TB, I don't think you'd need to keep anywhere near that percentage free.


    Message was edited by: WZZZ

  • ds store Level 7 Level 7 (30,310 points)

    John Kitchen wrote:


    HDDs may give trouble, but they can be replaced.


    Also the new iMac's hard drive can only be replaced by Apple now, at a CONSIDERABLE price, likely in excess of $600 (that's what I was quoted for a simple MacBook Pro drive replacement a few years back, a iMac is a lot harder task)


    The problem is Apple has installed a proporietary piece of software on the hard drives in iMac's for heat control and some sort of extra connections, so unless you find a third party company that can install this software for less than Apple.


    Also you absolutely need to learn how to CLONE your iMac hard drive to a external Firewire 800/USB drive using the free Carbon Copy Cloner, the reason for this is you can simply hold option while booting to boot off of it to keep using the computer.


    External USB hard drives are a mere $100 for a 1 TB, a lot less than replacing the internal drive.


    The iMac is a sealed up computer, no access to anything inside the machine (except perhaps the RAM) by anyone now is allowed (without breaking your AppleCare/warranty)


    Good luck

  • Edward Boghosian Level 4 Level 4 (1,395 points)

    No one can guarantee how many years of trouble free use one can get out of any computer including an Apple.  You may or may not have hardware problems within the  first year  or go five years without any problems which I doubt.  I would strongly suggest you get the extended warranty.  Many times, problems one has is not due to the computer but due to software that is added on or hardware connected.  Users seem to have problems with various routers used in their networks and trying to connect to the internet.  I think many times this type of problem is due to the router and not the computer.  Check out these support posts to get an idea of problems and how they may be solved.  But the first line of defense is your warranty .  Some people simply do not want to be bothered using it

    for different reasons but you paid for it-so use it.  That's what I think.  When you read these posts, you will get an idea how things work.

  • gangof4 Level 1 Level 1 (15 points)

    Thanks John and WZZZ!  Excellent advice.  I don't plan to store photos, data files, etc. on the hard drive but then as I slowly add apps to the dashboard, system upgrades, etc. I will lose space (currently at 98 gigs free.)


    I know the danger from heat and I've read that the iMac tends to run hot so keeping it as cool as possible is a priority to me.   I bought an APC 1500 UPS for surge protection and that's supposed to be a decent product.  We have momentary blackouts in my neighborhood so I don't want and peaks to wreck anything.  As far as a backup hard drive--do I just get like an iOmega or a LaCie external drive advertised in the Apple Store and then load OS X on it along with file storage?  I also have the 8GB 1333MHz DDR3 SDRAM so I guess I cannot add more RAM?


    Thanks again guys!

  • gangof4 Level 1 Level 1 (15 points)

    Hi Edward.  Thanks for the avice.  I did in fact get the extended warranty and Apple Care and then charged it on Am Ex which gives you an additional twelve months on top of what the vendor provides.  My router and ISP are Verizon.  Sometimes when I awaken the machine I get a "cannot find router" error but it corrects itself in seconds after that.

  • WZZZ Level 6 Level 6 (12,695 points)

    Check these out from OWC. I don't know the Apple prices for external drives, but I'd imagine they'd be pricey. OWC has decent Mac compatible stuff. I don't know the lastest models, but I'd guess you can add more RAM to the stock 8GB -- but could be wrong about that. Look in your user guide. Could look around the OWC site for RAM.



  • WZZZ Level 6 Level 6 (12,695 points)

    A current, more realistic, screenshot of temps in summer weather. We're having an early heat spell here and the room temp is around 80F. (The ambient in the screenshot is way off.)


    Screen shot 2011-05-30 at 10.06.07 AM.png

  • John Kitchen Level 3 Level 3 (645 points)

    Hi gangof4


    Sounds like you may have already filled the HDD to the danger zone if you only have 98 GBs free.  What's the HDD capacity?


    The story about heat is often misunderstood.  You'll see a lot of posts where people say that their aluminum bodied Mac feels hot to the touch and therefore there is a problem.  The opposite is true.  If you can feel the heat, the internal fans and the aluminum are doing their job of moving the heat from the inside if the computer to the outside.


    It's not possible to measure the temperature of the internal components by putting a hand on the outside of the case!


    You dont need to worry about the issue of the new HDD interface that Apple is using.  By the time you are out of warranty, you'll be able to buy affordable, suitable drives from the usual outlets and take one to your local Apple-accredited service shop and have them instal it.  It's just that it is new, and at this time Apple is probably the sole source of those drives.  In four years time, things will be different!

  • gangof4 Level 1 Level 1 (15 points)

    Hi John,


    It's a 1 TB drive (unfortunately the smalled of the two options) :/

  • WZZZ Level 6 Level 6 (12,695 points)

    You should be OK with 98GB free. You would probably be OK with even less. As I said, I don't think the free space recommendation of 15-20% is linear. This recommendation was before the era of such huge drives. The system needs free space to write temporary files. The amount it needs is not going increase with the amount of data -- usually your Home folder items like movies, music etc. --  on the drive.