It's going to take a while, you have a sizeable chunk of aluminium and while aluminium is "light" and conducts heat well, you still have thermal mass to deal with. I have a midplate thermistor on mine so it'll take a bit longer than someone with a thermistor on the heater itself (my heater didn't come with one so I drilled 2 holes, one for the sensor, other is tapped and is the hold down screw) I'd estimate somewhere around 10-15 to 60 and around 20 to 100. You want to give the chamber time to soak anyhow, equilibrium if you can wait, 30-45 once it reaches temp is usually good enough depending on what you're printing.
It's no bedslinger where it's at temp in 5 ish minutes, but you get way better chamber temps if you wait, if I intend to print I'll have it preheat an hour or so before I do anything, really do get better results if you're patient though, that way everything's nice and warmed up to minimise expansion while printing.