TYPO3: Speed up your BE easily
Surfing around the (TYPO3) web I found a post which should help you speed up your backend. All you have to do is enable some ‘hidden’ _.htacess files. I have no real proof it will work, but I think it does.
Just enable them, you can always restore it..
/_.htaccess typo3/gfx/_.htaccess typo3/mod/user/ws/_.htaccess typo3/sysext/_.htaccess typo3/sysext/t3skin/stylesheets/_.htaccess

As from TYPO3 v4.3, all of these .htaccess files are automatically enables – except from /_.htaccess. So the speed is included from this version onwards