Should I defrag or do a clean install?

You could create a mavericks usb installer. Boot from the installer use disk utility and divide the hard drive into two equal partitions. Clean install or restore mavericks from time machine to the first partition - then download and install yosemite to the 2nd partition. That way you have your working mavericks running and can test out yosemite to see if you get the better performance you wish.

unless you already have a backup with mavericks or a disk image of mavericks on you at this time it is no longer available for download from Apple.

I would start by having the community look at your EtreCheck output to see if there are some 3rd party additions that may be contributing to your performance issues.

<https://discussions.apple.com/docs/DOC-6174>

A clean install (Nuke & Pave) has benefits in that you do not bring over a lot of accumulated crude from the previous system. Then install just the apps you really need, and transfer your personal data.

When doing a clean install, ALWAYS make a backup, preferably 2 onto different external drives, using different backup utilities (Time Machine can be one, and a system cloning utility, such as Carbon Copy Cloner (free 1 month fully enabled demo) or SuperDuper (always free for a full clone)).

1. Defrag is done automatically by the OS. Launch Disk Utility. Whatever free space is shown at the bottom of the diagram can be user for a second partition.

2. Doing a clean install is worth the effort only if you also manually reinstall all other apps and utilities. Otherwise, you're just recreating what you already have.

Although creating a separate volume to run Mavericks is possible, switching between volumes and maintaining parallel app collections, not to say anything about documents, or libraries created with newer app versions, not being compatible with older apps on the Mavericks partition (i.e., iTunes library, Photos Library, etc), will require so much effort that you'll soon regret taking this road.

If the slowness you're experiencing is with just some specific apps, there might be ways to increase their performance individually - post those issues separately.

The basic problem you have with Yosemite is that you're running it with very little RAM. An upgrade to 8GB might well be worth the $50-$75 cost involved.

Just my 2 cents...

When you see a beachball cursor or the slowness is especially bad, note the exact time: hour, minute, second.

These instructions must be carried out as an administrator. If you have only one user account, you are the administrator.

Launch the Console application in any of the following ways:

☞ Enter the first few letters of its name into a Spotlight search. Select it in the results (it should be at the top.)

☞ In the Finder, select Go ▹ Utilities from the menu bar, or press the key combination shift-command-U. The application is in the folder that opens.

☞ Open LaunchPad and start typing the name.

The title of the Console window should be All Messages. If it isn't, select

SYSTEM LOG QUERIES ▹ All Messages

from the log list on the left. If you don't see that list, select

View ▹ Show Log List

from the menu bar at the top of the screen.

Each message in the log begins with the date and time when it was entered. Scroll back to the time you noted above.

Select the messages entered from then until the end of the episode, or until they start to repeat, whichever comes first.

Copy the messages to the Clipboard by pressing the key combination command-C. Paste into a reply to this message by pressing command-V.

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If all you want to do is repartition your disk, then I would clone everything to an external device, boot from the clone, repartition the internal device, restore the internal from the clone. I would have a 2nd backup as I never want to have just one copy of my data.

You will have a partitioned internal device, the data you restored will also be contiguous as a side benefit.

liam1101 wrote:

I understand that OS X doesn't require routine file defrag'g but I'm specifically looking for free space coalescing as a possible path to my dual partitioning goal.

You do NOT need to "defrag" or "coalesce" anything. Just launch Disk Utility, select your drive, click on the Partition tab. All free space will be shown as a single block. That's it. No other housekeeping needs to be done.