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iMac 27 i7 Really Slow - Upgrade to SSD?


Well-known Member
Morning all,

I have an Apple iMac 27, good spec, i7 with 16gb RAM, standard 1TB HDD. However, it’s painfully slow! It takes an age to boot up and trying to open any apps takes forever. I don’t use it for much, only occasional internet for my business, email, Word nut mainly Aperture for photo storage and editing.

It runs a standard 1TB internal HDD, a 2TB USB 2.0 external HDD (for storing my photo library and music library) and a 3TB Thunderbolt external backup HDD.

I’m wondering if there’s a better way to store everything. I could probably cut down my photo library considerably by deleting many thousand F1 photos (usually have 3 or 4 of the same car and I’ve been too lazy to sort through it!) and there are a few apps on the machine itself I could get rid of.

Currently I believe my photo library is around 700gb and the music library is around 60gb.

I’m wondering about getting two SSD drives, one internal, the other external. Run the internal one for apps and music, and the external one for my photo library. Good idea? Presumably this would improve the speed of things considerably. What size internal drive would be sufficient? I could move my iTunes library 60gb onto the internal drive, and it would need to store the OS, MS Office and Aperture itself. Aperture’s library could be stored on the external 1TB SSD.

Many thanks,



Well-known Member
Have a search on here for Fusion Drive. Lots of posts and a guide too. You can combine two drives internally via OS X (SSD & HDD) to create one drive with a fast cache (the SSD side). So you could get a 512GB SSD or 1TB SSD and a 4TB HDD, use Fusion to make one drive and all the stuff that's regularly accessed, like OS X, apps, most used files will run from the faster SSD cache side and less frequently stuff will stay on the HDD.

There's a kit you can get to mount the HDD in the Super Drive bay so both drives have the fastest access they can. Then the super drive can be mounted in an external usb casing for as and when you need optical media. You may also need a fan speed adapter depending on your iMac model.



If you see a few posts down, I've just had a 250GB SSD installed alongside my OEM 1TB HDD by Macupgrades.co.uk and the difference in speed is night & day!

I have nowhere near as many pics as you do; but my iTunes is around 450-500GB in size

I use MS Office, Adobe, Chrome and iTunes all the time, the difference in using them now to before the SSD was fitted is unbelievable

Also, boot speed has gone from around 3-5mins to more or less 11 seconds! It really is that fast

I know the 27" iMAC is a screen off job to fit the SSD, so if you're brave enough, the SSD and fitting kits are easy enough to buy. But, if you're like me and not that brave, then I can highly recommend Macupgrades to do the work for you :)


Well-known Member
I had a 1 TB SSD fitted to my 2011 27 inch Imac i5 - the difference is night and day boot speed is a bout 15 seconds and 1 icon bounce to load iPhoto and ITunes. I just took out the old drive had it cloned and replaced with the new 1 TB Personally I wouldn't mix HDD and SDD and also the bigger the SSD the quicker it gets! They aren't as cheap as HDD but they are a damn site cheaper than a new Imac - and when you've experienced the SDD you wont be looking at upgrading any time soon!


Active Member
Hmmm. There is no reason why such a system would be so slow that an upgrade is the only option to cure it, there must be an underlying problem. Fine if you want to upgrade for whatever reason, but I am sure there must be a problem such as a failing hard drive or too many background items being loaded for system/user. For example I look after two much lower spec (2009 C2D) systems and both still perform perfectly well. One is in a recording studio and used with professional audio software and still flies though admittedly left several updates behind (Mavericks) for stability reasons. The other is a more general day to day with perhaps iPhoto/Photoshop being its most demanding task.

I know speed seems to have dropped with each release since Mountain Lion but often anything more noticeable is down to hard drive problems. Both the above systems are left in sleep mode for wake-on-lan connections but even so boot in less than a minute on the very rare occasions that they need a cold start. Maybe a session with Disk Utility verify/repair and then if necessary a diagnostics tool like Techtool Pro. In my experience starting with disk troubleshooting then investigating startup items/daemons finds the vast majority of performance problems.

Hmmm. Thunderbolt. So its at least a 2011 model? You really must get your media data onto thunderbolt, the USB 2.0 drive must be very limiting in your situation. Unless you go all Thunderbolt (expensive) then using the Firewire 800 port or ethernet or even WiFi for backup are worth considering.


Novice Member
Check your hd model buddy

I had a 2010 iMac with same issue turned out to be faulty seagate drive which was covered by Apple

New drive is much better

Not ssd but not 5 mins slow either

Hope this helps

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