Performance increasing relative to variation

[philsmd]

0.9:c0XXXX906aXXXXc1XXcdXX0bXXXXf4XX

This just confirms that you are not familiar with the very basics of oclHashcat/hashcat and are not willing to learn/read a little bit (as I suggested above). See for instance https://hashcat.net/wiki/doku.php?id=example_hashes it explains each and every hash format (for good reasons, to avoid questions like this).

No, to make oclHashcat not change the left-hand side most-frequently, you need to change attack modes, e.g. -a 6 which uses a wordlist + a mask, dict_on_left_side.txt, mask on right side. But for just one static string "0.9" instead of a wordlist it might not be the best solution, but you can still test it to see the speed differences.

Code:

oclHashcat64.exe -w 3 -m 10 -a 6 -1 56789 c0XXXX906aXXXXc1XXcdXX0bXXXXf4XX:56dbXXXXbababXXXXbe8d6XX dict_on_left_side_containing_0.9.txt ?1?d?d?d?d?d?d?d?d?d?d?d?d

btw: I still think that the -m 20 method will be the fastest of all variants mentioned within this thread (but I didn't actually test it), btw by looking through your -m 20 command I discovered another problem: the "?5" within your mask is of course not correct, maybe it should read ?1?d?d?d?d?d?d?d?d?d?d?d?d56dbXXXXbababXXXXbe8d6XX