Honored Contributor
Honored Contributor10 minutes to config from a serial device is totally unreasonable, if you read the Config Handbook, "Estimating Active Serial Configuration Time" section you can calculate what the reasonable times are for your device size.
Maybe there is a problem with your hardware? Use a scope to check the config pins on the FPGA if possible (CONF_DONE, INIT_DONE, nSTATUS, nCONFIG) and see if they match the waveforms in the datasheet. If you see nSTATUS flicking high-low repeatedly (you should have access to it since it requires an external pull-up), it means you have a config error, maybe bitstream corruption. Make sure you use compressed bitstreams, also you can try a 40MHz config clock. Check the enable user-supplied startup clock in Quartus device options (should be disabled) and the CLKUSR pin (should be tied to GND if not used as an I/O).
