I'm running Apple Mail 5.3 and Thunderbird 17.0.4 on Mac OS Lion 10.7.5. The system I'm running those apps it's an iMac with 3Gb of RAM and 2.4 GHz Intel Core 2 Duo.
I run both applications at the same time and I got those results looking with the Activity Monitor.
As you can see, Apple Mails consumes a little bit less than Thunderbird but uses more virtual memory.
My question is, which one has better performance? Apple Mail or Thunderbird? I ask this because that was a puntual test, and I don't know if they get stressed when looking for RSS feeds or email on the inbox.
Do you know any other mail app which works better looking on the performance?
Best Answer
In general, Apple Mail should perform better than Thunderbird. This is for a few reasons. Apple Mail is built using Apple's current development platform, Cocoa. Cocoa allows for access to more recent, native APIs on the Mac: things such as OpenCL, Grand Central and Core Animation. It is also programmed natively in 64-bit mode. And lastly, Thunderbird is no longer being developed and has an older code-base.
What this means to you is that Apple Mail can take advantage of the built-in hardware, allowing software to do less of the number crunching, and giving you better overall performance. It will also allow you to use more memory (though it is unlikely any Mail program will regularly need more than 3.5GB of memory).
This explanation does not take into account any additional tasks one mail program may do over another, such as using a plug-in for Apple Mail.