I just got a new iMac Early 2009. It's running Mac OS X 10.6.8. I was wondering which Mac OS X version it would be faster to run on since it cannot run the latest macOS. As a developer that is new to Mac, I want something that will be fast and compatible with my current hardware situation & Development Tools. I was thinking Yosemite 10.10 or Mavericks 10.9. Any suggestions on what I should do?


Intel Core 2 Duo running on 2.66 GHz.

2Gb of RAM

Model Identifier is "iMac9,1"

If you need anymore specs just let me know.

  • "a new iMac Early 2009" in the year 2017 is still 8 years old! What are your dev tools?
    – klanomath
    Jul 2, 2017 at 2:19
  • Welcome to Ask Different. :) I have to agree with @klanomath - we really need to know what dev tools you use? Only then can you determine what version of macOS (and how much RAM) you need to use those tools. Once you know that, work back from there to see if you can use this iMac and, if so what you need for it to work well in your scenario.
    – Monomeeth
    Jul 2, 2017 at 3:52
  • What is the screen size 20” or 24”?
    – bret7600
    Jul 2, 2017 at 12:34
  • My Development Tools are Python 2.7 with Pygame and PyQt 4 (doesn't work so well on 10.6.3.), a MAMP server with PHP & MySQL along with an FTP Client, and I also want to be able to use Swift and Xcode.
    – OrionDark7
    Jul 2, 2017 at 15:47
  • My screen size is also 20".
    – OrionDark7
    Jul 2, 2017 at 15:48

2 Answers 2


I'm was sorely rempted to -1 your question and then comment, but the comment grew long. You're just trying to make the most of what you have and asking for advice so that's a +1 now.

Unless you define what "fast" is - it's hard for this not to be entirely speculative. Worse, when you define fast - then you make it very narrow and less useful.

The OS doesn't really change your CPU and your memory speeds. It doesn't change your filesystem and since you can't run High Sierra and APFS - you're stuck on HFS+ for that Mac.

About the best thing that can come of this "let's get an answer on which is faster - 10.11 or 10.12 or 10.10" is the suggestion to partition your drive and test each OS to your needs and then make your call.

The downside is you'll likely lose so much more time doing the measuring than just installing the latest OS that runs and then look to optimize what your bottleneck is when you reach them. Another downside would be if someone saw "10.12 is slow" and it discourage them from upgrading when for them it would be faster and/or more secure and no more slow.

I'd say - make a good backup, and then upgrade to the latest OS you can. Old software and not keeping your drive clean from needless files is likely to be far slower than whatever marginal difference you could ever measure on OS versions.

The upside of this is you'll have learned some skills on measuring performance and thinking about the end goal "swift and Xcode" and then can make decisions like - should I spend $$ on RAM and SSD or find a used Mac with those that is more economical than upgrading a core2 duo machine.

  • Yeah, I'm gonna try to update to OS X El Capitan, which is the highest my iMac can upgrade to, but I'm having a couple of difficulties. Thanks for your help.
    – OrionDark7
    Jul 8, 2017 at 21:07
  • I was going to suggest the same. i Have an early 2008 MacBookPro 17'' So I am forever stuck with El Capitan. For development reasons I suggest you to upgrade to it, though perhaps it will eat a bit more resources, you'll be probably forced anyway to upgrade to be able to host the newest programming language versions. I have 4GB RaM installed, which isn't much and the most important speed upgrade I can really recommend is to switch to a Solid State Harddisk. (They are really much much much more faster, but force you to work with complete backups as when they fail, they fail completely.) May 2, 2018 at 14:38

With only 2GB for RAM, you can only run OS X Lion, as other System updates require 2GB of RAM, but run optimally with ~8GB. You are welcome to upgrade this to run a newer OS, but you will need to buy more RAM. Apple’s website says that your Mac can support

2GB (two 1GB SO-DIMMs) or 4GB (two 2GB SO-DIMMs) of 1066MHz DDR3 SDRAM; two SO-DIMM slots support up to 8GB

For more info, you can see this article on the Apple Support Site.

As with any Mac, the factory OS will always be the fastest, but for the best security, the newest is best. Since you are on the lowest specs, Snow Leapord is likely the best way to go.

Another way to make your iMac blazing fast is to install an SSD instead of the factory HDD. Step step to do this can be found on iFixit

  • Really? I have a white 13" MacBook (late 2009) with 2GB memory running EL Captain.
    – lhf
    Jul 3, 2017 at 1:11
  • Yeah, I'm running Snow Leapord, but I updated to 10.6.8 just in case (I'll edit the post.). The thing is, I can't run most of my development tools on Snow Leapord, so that won't work for me, sadly.
    – OrionDark7
    Jul 4, 2017 at 4:53
  • I second the SDD recommendation. It makes a huge difference in responsiveness (and performance).
    – nohillside
    Jul 6, 2017 at 11:02

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