IMac – Why is the late 2013 iMac so slow


For the last three months I have been more or less enjoying my new late 2013 21" iMac. I already have an early 2011 MBP, which is pretty maxed out with a 512GB SSD and 8 GB of RAM, and still feels very, very fast.

The iMac has 8 GB RAM as well, but "only" the Intel Iris GPU and a 1TB SATA HDD. Both machines are running OS X 10.9.4.

Starting up a few apps, like Mail, Safari and maybe iPhoto, takes ages. Sometimes up to 20 or 30 seconds. Whereas the MBP takes only a handful seconds. It's clear to me that the SSD gives a great performance advantage. But is it really that much…?

I also noticed in the systems report that the Iris uses sometimes up to 1.5 GB of RAM. This seems like a lot. I imagine that this could also hurt performance.

I also get a lot messages like these in the system log:

24.08.14 19:57:32,827 WindowServer[539]: disable_update_timeout: UI updates were forcibly disabled by application "iPhoto" for over 1.00 seconds. Server has re-enabled them.

These happen if I switch from one iPhoto event to another, or switch to my iCloud albums. On the MBP this happens instantly, without delay.

Update: Here are some screenshots of the activity monitor and Console logging:

CPU load
HDD load
RAM usage
Console logging

Best Answer

i've seen this on some of my machines... it is fixable (though ican't remember the details for my situation). but it will stay very slow until you clean out those ui/windowserver errors.

firstly: have you added any screensavers? have you safe booted to clean out caches and check HD?