Need to Speed my Mac up

Your first step should be to wipe the disk and install a fresh copy of the OS and set it up for how you will be using the machine.

Using a system inherited without doing this will almost always lead to subpar performance for your use.

Before buying a second-hand computer, you should have run Apple Diagnostics or the Apple Hardware Test, whichever is applicable.

The first thing to do after buying the computer is to erase the internal drive and install a clean copy of OS X. You—not the original owner—must do that. Changes made by Apple over the years have made this seemingly straightforward task very complex.

How you go about it depends on the model, and on whether you already own another Mac. If you're not sure of the model, enter the serial number on this page. Then find the model on this page to see what OS version was originally installed.

It's unsafe, and may be unlawful, to use a computer with software installed by a previous owner.

1. If you don't own another Mac

a. If the machine shipped with OS X 10.4 or 10.5, you need a boxed and shrink-wrapped retail Snow Leopard (OS X 10.6) installation disc from the Apple Store or a reputable reseller—not from eBay or anything of the kind. If the machine is very old and has less than 1 GB of memory, you'll need to add more in order to install 10.6. Preferably, install as much memory as it can take, according to the technical specifications.

b. If the machine shipped with OS X 10.6, you need the installation media that came with it: gray installation discs, or a USB flash drive for a MacBook Air. You should have received the media from the original owner, but if you didn't, order replacements from Apple. A retail disc, or the gray discs from another model, will not work.

To start up from an optical disc or a flash drive, insert it, then restart the computer and hold down the C key at the startup chime. Release the key when you see the gray Apple logo on the screen.

c. If the machine shipped with OS X 10.7 or later, you don't need media. It should start up in Internet Recovery mode when you hold down the key combination option-command-R at the startup chime. Release the keys when you see a spinning globe.

d. Some 2010-2011 models shipped with OS X 10.6 and received a firmware update after 10.7 was released, enabling them to use Internet Recovery. If you have one of those models, you can't reinstall 10.6 even from the original media, and Internet Recovery will not work either without the original owner's Apple ID. In that case, contact Apple Support, or take the machine to an Apple Store or another authorized service provider to have the OS installed.

2. If you do own another Mac

If you already own another Mac that was upgraded in the App Store to the version of OS X that you want to install, and if the new Mac is compatible with it, then you can install it. Use Recovery Disk Assistant to prepare a USB device, then start up the new Mac from it by holding down the C key at the startup chime. Alternatively, if you have a Time Machine backup of OS X 10.7.3 or later on an external hard drive (not a Time Capsule or other network device), you can start from that by holding down the option key and selecting it from the row of icons that appears. Note that if your other Mac was never upgraded in the App Store, you can't use this method.

3. Partition and install OS X

a. If you see a lock screen when trying to start up from installation media or in Recovery mode, then a firmware password was set by the previous owner, or the machine was remotely locked via iCloud. You'll either have to contact the owner or take the machine to an Apple Store or another service provider to be unlocked. You may be asked for proof of ownership.

b. Launch Disk Utility and select the icon of the internal drive—not any of the volume icons nested beneath it. In the Partition tab, select the default options: a GUID partition table with one data volume in Mac OS Extended (Journaled) format. This operation will permanently remove all existing data on the drive.

c. An unusual problem may arise if all the following conditions apply:

OS X 10.7 or later was installed by the previous owner

The startup volume was encrypted with FileVault

You're booted in Recovery mode (that is, not from a 10.6 installation disc)

In that case, you won't be able to unlock the volume or partition the drive without the FileVault password. Ask for guidance or see this discussion.

d. After partitioning, quit Disk Utility and run the OS X Installer. If you're installing a version of OS X acquired from the App Store, you will need the Apple ID and password that you used. When the installation is done, the system will automatically restart into the Setup Assistant, which will prompt you to transfer the data from another Mac, its backups, or from a Windows computer. If you have any data to transfer, this is usually the best time to do it.

e. Run Software Update and install all available system updates from Apple. To upgrade to a major version of OS X newer than 10.6, get it from the Mac App Store. Note that you can't keep an upgraded version that was installed by the original owner. He or she can't legally transfer it to you, and without the Apple ID you won't be able to update it in Software Update or reinstall, if that becomes necessary. The same goes for any App Store products that the previous owner installed—you have to repurchase them.

4. Other issues

a. If the original owner "accepted" the bundled iLife applications (iPhoto, iMovie, and Garage Band) in the App Store so that he or she could update them, then they're irrevocably linked to that Apple ID and you won't be able to download them without buying them. Reportedly, Mac App Store Customer Service has sometimes issued redemption codes for these apps to second owners who asked.

b. If the previous owner didn't deauthorize the computer in the iTunes Store under his Apple ID, you wont be able to authorize it immediately under your ID. In that case, you'll either have to wait up to 90 days or contact iTunes Support.

c. When trying to create a new iCloud account, you might get a failure message: "Account limit reached." Apple imposes a lifetime limit of three iCloud account setups per device. Erasing the device does not reset the limit. You can still use an iCloud account that was created on another device, but you won't be able to create a new one. Contact iCloud Support for more information. The setup limit doesn't apply to Apple ID accounts used for other services, such as the iTunes and Mac App Stores, or iMessage. You can create as many of those accounts as you like.

Back up all data to at least two different storage devices, if you haven't already done so. One backup is not enough to be safe. The backups can be made with Time Machine or with Disk Utility. Preferably both.

Erase and install OS X. This operation will destroy all data on the startup volume, so you had be better be sure of the backups. If you upgraded from an older version of OS X, you'll need the Apple ID and password that you used, so make a note of those before you begin.

When you restart, you'll be prompted to go through the initial setup process in Setup Assistant. That’s when you transfer the data from a backup.

Select only users and Computer & Network Settings in the Setup Assistant dialog—not Applications or Other files and folders. Don't transfer the Guest account, if it was enabled.

After that, check the App Store for software updates.

If the problem is resolved after the clean installation, reinstall third-party software selectively. I can only suggest general guidelines. Self-contained applications that install into the Applications folder by drag-and-drop or download from the App Store are usually safe. Anything that comes packaged as an installer or that prompts for an administrator password is suspect, and you must test thoroughly after reinstalling each such item to make sure you haven't restored the problem.

I strongly recommend that you never reinstall commercial "security" products or "utilities," nor any software that changes the user interface or the behavior of built-in applications such as Safari. If you do that, the problem is likely to recur.

Any system modifications that you do choose to install must be kept up to date. None is required for normal operation.

Before installing any software, ask yourself the question: "Am I sure I know how to uninstall this without having to wipe the volume again?" If the answer is "no," stop.

Never install any third-party software unless you know how to uninstall it.

If it's a system from someone you know and trust, then you can ask him about what has been installed, etc. If there is any uncertainty then consider formatting and reinstalling; however, this is not a necessity.

Your best bet in the long run will be to install more RAM; however, from the etrecheck results it shows your largest memory-using app is Chrome at ~215MB RAM, with other processes being significantly less. This indicates you have many programs open that collectively are using all of your RAM. Do you regularly keep many programs open, and if you restart your system without opening applications, do you see an expected amount of free RAM without the high memory pressure?

You may also want to consider an HDD-to-SSD upgrade.

Most of that are background services that are required for OS X to run properly. With that list, do you still see the memory pressure measurement high? I do not recommend you force-quit any of these processes, and only do so if there is a specific and known problem with one of them.

The 2 places I’ve seen recommended most to buy reliable RAM are below. I have purchased RAM several times from Other World Computing and have always been very satisfied with the product and service. They have on-line instructions on how to replace the RAM. OWC has also tested RAM above what Apple states is the maximum. I now have 6GB installed on a machine supposedly limited to 4 GB.

Crucial

Other World Computing