s19 90th help

[lukamagic11]

I bought some s19 90th and I have some questions on them if anyone knows would appreciate it a lot..
1. What's the difference with 82, 86 models and what is with 95 that has a higher premium in price too.
2. What are these 88 chips models, for what s19 refer to?
3. Does the 90th model come with apw121417 psu, and what the differences between this and apw121215. Which is better and more trustworthy and what are their limitations in order to not overstress them.
4. I was thinking to use vnish firmware, but I heard that I can not even oc this model, because power supply will instantly die, it is already stressing too much at stock th
5. Is it recommended using external air cooler despite better temps, on the longevity of hasboards.. And also by removing stock fans I alleviate some psu wattage but on the 12v rail.. Does the 1417 psu model get any help with this?

[ZeusBtc.com]

You can check the specifications of the Antminer S19 model, APW12 1417, and APW12 1215.
https://support.bitmain.com/hc/en-us/articles/900000253583
https://support.bitmain.com/hc/en-us/articles/9325432472473-APW12-14V-17V-Specification
https://support.bitmain.com/hc/en-us/articles/900001205726-APW12-12V-15V-Specification
These power supplies are not compatible, APW12 1417 is suitable for S19, L7 and other models, APW12 1215 is suitable for E9, T19, S19j and other models.

[lukamagic11]

Thanks for the reply, I saw these articles in the past too, that's why I am asking because the 1215 model says max 240amps at 15v (3600w) but the 1417 says 182amps at 17volts!? (3094 watt) .. So is 1215 more reliable and delivers more amps or the articles in bitmain are misleading?