Topic: Understanding hash rate metrics (Read 476 times)

Using sgminer, I see a number of different ways that the mining is measured, and even after reading through a few posts, I am not entirely sure what the difference between these calculations is.  Namely:
[from the sgminer-gm Readme](https://github.com/sgminer-dev/sgminer/blob/master/README.md)
Each column is as follows:
5s: A 5 second exponentially decaying average hash rate   
avg: An all time average hash rate   
A: The total difficulty of Accepted shares   
R: The total difficulty of Rejected shares   
HW: The number of HardWare errors   
WU: The Work Utility defined as the number of diff1 shares work / minute (accepted or rejected)   

It seems that miner output can be measured in number of accepted shares / minute (work utility) or in hash rate.  Which one of these should be tuned for optimal pool mining?  Are pools measuring accepted shares or hash rate or some variation of the two?   

As a concrete example, using sgminer, I am getting the following from my cards:   

GPU1                | (5s):652.4 (avg):652.2h/s | A:26316032 R:144000 HW:0 WU:26914.2 rI:1016   
GPU3                | (5s):652.3 (avg):652.3h/s | A:25902032 R:90000 HW:0 WU:27196.71 rI:1016   

GPU0                | (5s):741.5 (avg):741.0h/s | A:21024026 R:36000 HW:480 WU:22027. rI:1016     
GPU2                | (5s):744.7 (avg):744.8h/s | A:22500028 R:54000 HW:436 WU:22573. rI:1016   

GPU4                | (5s):723.0 (avg):723.1h/s | A:28782035 R:108000 HW:0 WU:29469.1 rI:1016   
GPU5                | (5s):723.0 (avg):723.0h/s | A:29196036 R:90000 HW:0 WU:30270.72 rI:1016   

uptime about 12 hours... 
I understand that we have to take electricity consumption into account to get a true metric, but ignoring that for now, what is the strongest card? 
GPU1 and 3 have noticeably low hash rates, but their work utility outperforms that of GPU0,2. 

GPU0,2 have the highest hashrate, but they have hardware errors (is that a lot for 12 hours?) and their work utility is the lowest of all cards. 

GPU4,5 have the highest work utility, however their hash rates are lower than GPU0,2.   

If anyone has insight, it would be appreciated. 

For the curious, I am using sgminer-gm, all Sapphire rx480 4gb Nitro+OC gpu's with custom roms on Ubuntu 16.04.  All ROM's are custom, but GPU1,3 had different ROM's to start with.