Peculiar speed differences between two 11Cs

[Dave Britten]

I've got two 11Cs, both made in USA, one in 1982 and the other in 1985. The 1982 model has a somewhat more sluggish response in its LCD, most noticeable in the leftmost digit, where the segments tend to be a bit delayed in updating. Also, when "running" is flashing, the speed of flashing is slower than the 1985 unit.

But the weird thing is that, despite the faster display updating, the 1985 seems to run about 10% slower (very rough estimate based on just eyeballing the completion times of the 8-queens benchmark - it was a good few minutes' difference).

Is this a hardware design/revision difference, a manufacturing/tolerance difference, aging components, or something else?

Slightly unrelated, the 1982 has heavier but darker orange paint for the keyboard labels, whereas the 1985 is thinner but much brighter.