the 2 S5+ have been connected close to 6 days the sp yukon 25 minutes,
Variance is a big part of, and always present in, bitcoin mining
Well the best way to see what you are being rewarded over a short time frame is:
Look at the cgminer API summary two numbers:
E: "Elapsed" and D: "Difficulty Accepted"
Paid GH/s = 2^32 * D / E
Now in case you didn't want to do that ...
Look at the Workers->Shifts page.
That's how it calculates the "Avg Hs" which will be over the time frame given "Length"
i.e. 2^32 * "Your Diff" / "Length" seconds
For my 2 A6s and sjc's S3 I see over the last 4 completed shifts:
5pcu3 paru Dec-14 23:49:21 45m 47s 7.71THs
5pcoq origami Dec-14 23:02:38 46m 43s 7.03THs (pool restart)
5pcha nodoka Dec-14 22:54:42 7m 55s 7.30THs
5pcgb mutsumi Dec-14 22:15:04 39m 38s 7.61THs
About a 10% difference from min to max
If you had failover during the pool restart you'd see that under "origami" since that was the shift that was created when ckpool restarted
Even a shift will have variance since it's only ~40min or in one case above, ~8min
Of course there's also the question of how much time your miners spent else where due to the failover or for any other reason.
You'd have to look at your miner's stats to see that.
