You can probably get further by changing how you work instead of making Drupal faster on page loads.
The main thing here is using Drush to do stuff like clearing the cache (Even when disabling the page cache, there is still dozens of different caches involved, for example for hook implementations), installing/re-installing modules and so on.
And of course, APC should be installed, yes. You could even think about using http://drupal.org/project/apc to store parts of the cache in APC. This will however conflict with drush (you can't clear the APC cache by using drush) and will require additionaly RAM.
Thought I'd post my experience which may help future readers. I struggled with for over 24 months with a really slow Drupal 7.3x stack on an Ubuntu 15.04 desktop (I just couldn't be bothered to with more pain and just carried on!). Today, I took a stab at installing MySQL Workbench 6.1 and it now flies by! Unbelievable!! I hope any future readers will consider this first as none the suggestions offered really solved my issues. The machine I use is a fair decent spec (16g RAM/dual core/2TB/Dual-head etc), so buying/getting 'another computer', I don't believe is the true answer. In all, if you are running Drupal on a desktop then try the above Workbench install first. To date, I've found I need to run Workbench in the background (or on another screen), still my whole Drupal experience has now improved immensely.
Maybe I have just been luck today? Anyway, hope this helps future readers.
Not only are you running apache/php/mysql on it you are also running a GUI and a IDE, probably multiple web browsers, skype, itunes all of which compete for resources. Making you drupal install and your whole machine slow.
Alternatively, have a separate machine with the Drupal install on to help spread the load.