saphire nitro+ radeon rx 570

[shap00]

   i have a problem and i hope to get some guidance here. i made a new saphire nitro+ radeon rx570 rig and i got 20 mh/s per card. if i try to use msi burner or wattman i reach 22.2 but with enormous power consumption. so after 2 days of research i found out that i have to do some changes in the card bios. after i saved the initial bios of every card, i used polar bios editor to make changes (i modified the timing values from 2000 and 1850 to 1750 timing value) and after i flashed it it crashed. i brought two of the gpus to the initial state and is working fine but the third one isn't working anymore. if i connect it to the rig or i connect the gpu alone, the computer freezes when it tries to enter windows. I checked the connections and the energy and it looks good.
   Did i broke the card? if yes, why are the other two working fine, if no, how can i repair it?
   Can some one tell me what should i do to get more mh/s at with lower power consumption?
   hope i'll get answers. peace and love!

[1715408256]

1715408256

[1715408256]

1715408256

[blueflame]

Hey there I have some Nitro+ RX 570s 4gb too. Have you ran using the ATI Pixel Clock Patcher after flashing the bios? (heres the link -> https://www.monitortests.com/forum/Thread-AMD-ATI-Pixel-Clock-Patcher). Heres why you need to patch the bios https://www.reddit.com/r/EtherMining/comments/6mcwdm/noob_question_amdati_pixel_clock_patcher/dk0ojvt/?st=jbdqcjjx&sh=27faa4b7. Also have you disabled Windows from auto updating drivers, thats given me problems in the past. I'm getting 28mh/s ETH while dual mining on my rx 570s rn so hope you get yours working