26M - 28M 2^58
 

keeping other CPUs busy

Some statistics. All results for completed subranges have been sent to George
[code:1]
Range (M) Exponents Factors
26.0-26.1 2660 42
26.1-26.2 2597 31
26.2-26.3 2712 47
26.3-26.4 2640 54
26.4-26.5 2721 57
26.5-26.6 2727 44
26.6-26.7 2665 54
26.7-26.8 2651 45
26.8-26.9 2757 48
26.9-27.0 2737(*) 47
27.0-27.1 2736 54
27.1-27.2 2605 50
27.2-27.3 2735 33
27.3-27.4 2659 39
27.4-27.5 2697 37
27.5-27.6 2701 58
27.6-27.7 2586 44
27.7-27.8 2694 39
27.8-27.9 2665 40
27.9-28.0 2611 43
[/code:1]

(*) One additional exponent was already factored to 2^67

On your stats, by "Primes" you mean... factors :exclaim: :)

... oops

half of the subranges completed. See table above. Some results are already in nofactor

It's done. All results have been sent to George. A lot of them are in nofactor already (I believe 26.0-26.9 and 27.0-27.6)