[BUG?] gc and impatience

Hi,

I was pulling in some changes in the morning to find:

 Auto packing the repository for optimum performance. You may also
 run "git gc" manually. See "git help gc" for more information.

Being my usual impatient self, I opened another prompt and started merging changes. After the checkout, it started running another gc (why!?), which I attempted to kill using ^C.

  Counting objects: 449291   x$

It didn't just fail to stop, but it kept writing output making my prompt completely unusable. I finally just killed the pane. Now, it's struggling to update-index and update my cache (read: more waiting).

Why is gc not designed for impatient people, and what needs to be done to change this?

Ram