Bit manufacturers will specify a chip load, which is how much material is cut per flute per revolution of the tool. Feedrate = chipload x # of flutes x rpm. For example, if the chip load is .003, and your spinning a 2 flute tool at 20,000 rpm, feedrate = .003 x 2 x 20000 = 120ipm
If you don't know the chip load, you could find a similar tool at https://www.onsrud.com/xdoc/FeedSpeeds and use their chip load charts.
Unfortunately, I don't think optimizing your feedate will get the chips out of your cut. Especially with smaller tools, but even with 1/2" bits you'll still get this problem. The best option would probably be to blow compressed air on the cut, but vacuuming is better than nothing.