It would. Unless you could replace the electric heating with a heatpump though - then you would get more heat out of each kW you put in. But replacing an old-fashioned electric wall heater with a 1700 W mainframe would be totally equivalent. So no, a 1700 W computer isn't more 'inefficient' than a wall heater of the same wattage. The light is neglible and it too ends up as heat anyway.