In answer to user questions here is a quick tutorial on how to switch Logic Pro between 32 and 64 bit modes with a short note on performance.
With the advance of 64 bit operating systems and now the release of Mountain Lion, many users are understandably concerned about the performance of Logic Pro, how it is affected and that Logic Pro still says 32 bit on the startup screen when both the operating system and Logic are supposedly optimised to run in 64bit.
So what exactly is 64-bit and why is it an improvement on 32-bit?
The theory is that full 64-bit systems and components should naturally handle twice the workload as 32-bit systems. This is because in a 64-bit system 64 pieces of information can be processed at any one time as opposed to 32 in a 32-bit system. The result of this can be greater speed performance and an increase in the complexity of tasks your system is able to perform. There are of course variables in this, such as whether all of the tasks on your system are performed in true 64-bit at all stages, but on paper this is how it should work.
The amount of data to be processed at any one time is not the only advantage when using Logic Pro. A huge advantage of running Logic Pro in 64-bit mode is the ability for Logic to fully utilise all of the available RAM in your system. Logic running at 32-bit is limited to a maximum of 4GB ram usage, which means that using a few third party plug-ins can soon take up your available RAM, causing system system slowdown and disk error messages. With 64-bit mode, Logic is able to utilise all of your available RAM, naturally increasing it's ability to handle a greater workload. Therefore theoretically, depending on the amount of RAM in your system, you should be able to notice a difference in performance when switching to 64-bit, especially on plug-in heavy songs.
Here's how to switch Logic Pro between 32 and 64 bit modes:
Step 1:On your mac, navigate to the Applications folder and ctrl click on the Logic Pro icon. Select Get Info from the resulting menu.
Step 2In the resulting window about half way down you will see a button named Open in 32-bit mode which defaults to being checked. Unchecking this box instructs Logic Pro to open in 64-bit mode.
Start up Logic Pro. You will now see it says 64-bit next to version
Now when you load an Audio Unit instrument or plug-in, you can see that there is the usual Audio Units category, but also one now for any plug-ins which will only run in 32-bit mode. All others are 64-bit compatible.