better computer
better gear / more movement speed
better skill setup
better DB settings
better DB profile
better DB loot rules
...and probably a few more
Seriously though, you shouldnt even be concerned with gph, and contrary to popular belief that picking up all gold yields higher overall gph is false also. If you really want high gph numbers set minimum gold pickup to 300-400 and get as high dps as you can and just run mp0 act 3... (Considering 450 ares and 40k hp are more than enough to survive mp0 act 3, dump everything else on dps...). Back in the days when i was concerned with gold, this setup allowed me to reach around 650 gph on mp0 with ~150k dps unbuffed barbs.