Replace those vinyl hoses with silicone hose. Then you can run the water at full throttle.
It is also necessary to agitate the wort (stirring, shaking the chiller, tea bagging the hop bag is what I do) during the first 10 minutes of cooling.
My schedule is something like this:
Turn on chiller full blast, tea bag the hop bag for 10 minutes
Turn water to 1/3rd, let hop bag drain for a few minutes, slap the lid on and let it go for 10-15 minutes
If it's summer, I'll then switch to a pump to recirc ice water for 20 more minutes to get down to pitching temp. This time of year I'm good to go after 20-25 minutes.