Don't worry too much about that displayed 0.03% per hour rate, it tends to underestimate a lot.
My experience is the opposite when I start from scratch: the rate is quite uptimistic for the first hours, but becomes slower once it reaches more recent years of data.
That's normal for the older nearly empty blocks where there's little to no data to verify.
If he's getting that 0.03% per hour estimate at that part, the issue could be something more than just the hardware bottleneck.