I can't even understand how this can be, but after enabling Triple Buffering on my nVidia GeForce 8800 GTS 512, Cinnamon (1.8) boots up A LOT faster on my Samsung HDD!
Maybe it helps with other Desktop Environments, too? And how can Triple Buffering even affect boot-times at all?

PS: If you want to try this yourself, here is what I had to do first on Linux Mint 15 "Olivia", which is based on Ubuntu 13.04 (I know, will upgrade soon...):

There was no xorg.conf present, so I had to run this command first:
sudo nvidia-xconfig
Then just copy this line to your newly created xorg.conf under the section "Device":
Option "TripleBuffer" "1"
That's it!
Just reboot & enjoy the faster loading of Cinnamon!