Identifying the capacity and configuration of your currently installed RAM modules is something you will need to know so that you can purchase the most appropriate memory upgrade.
For instance, you may have learned that the maximum RAM upgrade your system can handle is 8GB, and you have 4GB installed currently, with two memory slots, but you are not sure if you have a single 4GB module, or 2x2GB modules installed.
You can find this out easily without having to open the machine:
CPU-Z is a small utility which, among other useful system information, provides information on the speed, capacity, and type of each memory module in each available slot, including if the slot is empty. Follow these steps to install and run this useful tool:
- Download CPU-Z (ver 1.89) from our website (2.5MB).
- Run the setup executable file, and let it guide you for the installation process.
- Wait for the program window to load (takes up to 30 seconds)
- Select the SPD tab, then look at the Slot # heading. This is the currently selected slot number. You can change this simply by choosing another slot from the menu.
- Check the Module Size heading. This indicates in MegaBytes the size of the module installed in the slot. (2048MB or 2GB in the above example)
- Check the Max Bandwidth heading. This indicates the maximum bandwidth and frequency of the module. (PC2-6400, or DDR2-800 in the above example)
Note: cpu-z always reports the raw frequency of DDR, DDR2, DDR3, DDR3, and DDR4 modules, which is half of the advertised speed. In the above example, the frequency is 400MHz, but the actual speed of the module is 800Mhz, or DDR2-800.
To get started, go to the apple menu (top left of your screen) and select About this Mac.
You’ll then be shown the below screen that displays your Processor speed and how much Memory (RAM) is installed.
However, to obtain more specific information about the size of the memory module installed in each slot, you'll need to click the 'More Info' button.
If you are running OSX Lion or higher, you'll see a window like the one below.
Click the System Report button to bring up the System Information utility. If you are running an earlier version of OSX, then the System Information utility should already be active.
Now select the Memory sub-heading to see exactly the number and capacity of the memory modules installed in your Mac.
Or watch one of the videos below: