If you want to cut as fast as you can without snapping bits, I highly recommend checking out G-Wizzard Calculator by CNC Cookbook. They have a free 30 day trial. For hobbyist you can buy a one year license ($79) that will give you full functionality for a year. After the year the calculator cuts back maximum power to hobby machines only - which is all you need for an X-Carve. I’ve found that once you have the calculator set up correctly for your machine it will provide the best speeds and feeds for just about any material. I have not snapped any bits since using this tool. I can usually go a little faster than the calculator suggests, but usually not by much.
For the record, I am not associated with CNC Cookbook, but I highly recommend G-Wizzard, especially if you buy pricey bits like I do.