Does the processor affect a computer's boot up time?

[Legolas8181]

Or is it just the HDD speed that does that?

 

[logainofhades]

The CPU can have effect, but the HDD speed affects things far more. A P4 with an SSD would boot faster than an i7 4770k with an HDD.

 

[2x4b]

The most significant bottleneck during boot is in time spent waiting for I/O (hard drive)
Microsoft employes several optimization strategies during this period to accelerate the process.

Only after files are loaded will the speed of a processor become a factor.