Please post your results, there are a lot of frequencies and setups, so please post the following in this format.
Batch: Batch#
Frequency: Freq#
Hashrate: Hashrate#
Power consumption: PowerConsumption# (If possible)
Fan Speed: FanSpeedPercentage#
Avg Blade Temperature: TempInCelcius#
Hardware Errors Per Day: HWerrors#
For example:
Batch: 6
Frequency: 575
Hashrate: 3.82TH/s
Power consumption: N/A
Fan Speed: 35%
Avg Blade Temperature: 54C
Hardware Errors Per Day: 3/day
Honestly for me every miner is a little different. With the exception of the 2 batch 7's the firmware is on those factory installed and on one of them I left it at 625 MHz and it mined at the advertised 5TH, the second batch 7 at 625 was performing poorly and I was only getting around 3.8TH so I dropped the freq to 600 and then is jumped up to 5TH. The 19 others I have are batch 2 (which were advertised to run at 4.66TH at 575 TH), I flashed them with the most recent Bitmain firmware that supports the 600Mhz setting. When I had the time I found that really going through them slowly and taking my time tweaking with the frequency (and not always up) making small changes has made an incredible difference. For instance, I have some of mine set at 606MHz and some set 593Mhz. I do not think I have anything set over 625 but you can certainly try. Just make sure you are monitoring it closely when you make changes like that. I guess the whole point I am getting at is there is not perfect setting for every single miner out there. You can have rough guidelines that work for most but if you are trying to dial in your farm, then you need to play with the settings to see what works with your farm. Also keep in mind not all miners are going to perform at the highest Th rating possible. Some of my miners no matter what settings I have changed and close I think I have dialed it in, I have had to settle for 4.5Th when I should be getting 4.8 and that ok, its just the way it goes. If you are interested you can check out my mining set up here
https://www.youtube.com/watch?v=K1C2LQnBr2Y If you like it, subscribe as I am always adding new content and I love audience feedback. I look at bitcoin as a group learning effort. In fact your thread has kinda of inspired me to create some kind of video addressing this very issue because I have seen this question or variations to this question come up before where people have had performance issues when dealing with several of the same type of bitmain products. They are frustrated why two or more of the exact same product do not operate the exact same way.
I hope this help!