Well, you don't really explain anything, I'm fine with that. I'm not sure what you mean by "at least looked at that one line of code". Yes it depends on chip clock, yes it depends on number of chips, yes, it depends on time per something that's coming from chip info structure (I assume live value) and some constant defined elsewhere. So what? Doesn't GPU calculation do essentially the same (GPU clock * number of calc units * some constant * variable time per calc) (I'm sorry I'm too lazy to dig up the actual line of code)?
I don't think I mentioned anything about GPUs, but I'm sure that the inaccuracy in Gridseed hashrate calculation can account for the difference you were seeing. You think that doesn't explain it - ok, let's leave it at that.
Maybe you can do the same experiment and report your results?
You didn't think I would make claims without actually having tested and understood the concept, did you? :-)
There you go - pool, diff, A:, R:
WafflePool 512 941568 17408
CleverMining 512 968704 22016
Middlecoin 1024 952144 16384
ScryptGuild 128 953600 4480
CoinShift VARDIFF 960448 10240
TradeMyBit VARDIFF 933632 7872
Hashco.ws VARDIFF 943440 20944
DogeP2P VARDIFF 958411 10220
Uptime approximately 12 hours 20 minutes. Four 5-chip Gridseeds for each pool. Scryptguild claims to be VARDIFF, but it never switched away from 128. TMB is low because it actually disconnects on coin switch, most other pools have figured out switching without disconnecting.