OS X 10.9 Mavericks: Enhanced Dictation Is a Memory Hog, and Doesn’t Work Very Well
OS X 10.8 Mountain Lion added a built-in speech recognition feature; you can talk to your Mac and it will type your words. It’s not great; it’s nowhere near as good as Dragon Dictate. I compared the two in a Macworld article last year.
Mavericks adds a new twist to this speech recognition feature. While the feature generally requires an internet connection – what you dictate is sent to Apple’s servers for transcription, then sent back to you, the same way Siri is on iOS devices – with Mavericks, you can use Enhanced Dictation. With this, you download a file (around 1 GB) which lets your Mac do the heavy lifting.

Unfortunately, this turns out to be quite the memory hog. Even when I’m not using it, the speech recognition process takes up nearly 1 GB of RAM on my Mac mini, which has 16 GB. That’s a lot of RAM for a process that’s not being used.

I was curious if this amount of RAM used was relative to the amount of RAM in my Mac. So I checked my MacBook Pro, which has 8 GB RAM. With Enhanced Dictation turned on, it uses just about the same amount of RAM: 980.6 MB vs 980.1 MB for the Mac mini.
If I turn off Enhanced Dictation, the standard speech recognition process only uses 17.8 MB.

So, if you use speech recognition on your Mac, be aware of the memory usage. If you only occasionally use Enhanced Dictation, think of turning it off when you aren’t using it, especially if your Mac doesn’t have a lot of RAM.





Hmm, I just checked & on my 2013 MBA I don’t see that kind of memory usage. The process only shows up after the first time dictation is used, and even then takes up only a few megs. Enhanced dictation is also much more responsive than using remote, even with fios.
Heh, minutes later (while not using dictation) I’m seeing the process using ~1GB. The current version of Activity Monitor is very buggy, and VM in 10.9 has changed so much I’m not sure what to believe.
And now reported usage has dropped to 380MB.
I notice having dictation active my iMac treats it as an active program which prevents it from going into sleep mode
Thanks. I was having the same problem. Around a gig of memory usage when I never use speech recognition. Ever. I turned it off.
Maybe you didn’t expect a comment on this at this late date, but I just noticed the memory usage of the Apple speech services and found this great article by searching Google. Just what I needed to turn it off. Saved me possibly ruining a new installation of Yosemite. Thanks, Kirk.
Just so you know, it only uses that much memory because it can, it makes speech interpretation much faster. There is no performance loss. Don’t worry about it so much. If you run low on memory it will use less all by itself, because the people that work at apple are not idiots.
If you want to disable it:
1. Open Terminal from Applications -> Utilities Folder
2. Copy this and paste into the terminal:
launchctl unload -w /System/Library/LaunchAgents/com.apple.DictationIM.plist
3. Press enter
4. Reboot