claymore eth hashrate drop with multiple cards

[shadowhlohavec]

Hello, I have rig with 2x rx 480 1x 470 1x 570, I flashed anoraks moded bios to all cards, first I tried 1 card only in the system, it gave me 29+mhs, overclocked... I plugged in 4 cards and the hashrate for the 2x 480 started at 29 with miner restart it dropped to 25 and now I can get only 25max, I tried flashing it again and changing few settings with overclocking but it's the same, I don't think it's problem with psu because I have 2x 550W. I don' know whats the problem... (when I tried again only 1 card, eth solo hashrate was 31.5mhs which is a bit over i think (samsung memory) then again ony 25 with multiple cards....)  (the hashrate for monero is 740hs for each card) any help appreciated

[xxcsu]

- You might be flashed the wrong bios for your card(s)
ppl downloading bios files from internet , and they have no clue , those bios files version number is probably different than what they have on they card with the same model number ...
I hope you saved your original bios files ..
my suggestion will be , flash back the original bios files for each cards !!! you should saved the bios for each cards separetly ... so two saved bios for each 480 , one for the 470 nad for the 570 , and try mining, see how the cards working with original bios.... make sure you rsetting all overclocking , undervolting software u used

-or you just have no idea how properly overclock undervolt your cards if you have a modded bios  

-or your 2x550watts psu not enough ...
If you have your system on one psu , cpu-mobo-mem-hdd and the 2 rx480 on the same 550w psu , that can be a problem also ...
Read this topic about rx 480 power usage

full system spec would be great , can be helpful to estimate your rig power usage

[shadowhlohavec]

- no it's the bios from anorak vbios collection so it should be okay
- clocks 1150/2100 and some undervolt might be okay
- 550w is enough, system is only 50w , cards 200 each

specs

Intel Celeron G3930
ASUS PRIME H270-PLUS
60gb ssd
4gb ram

[Pekine]

did you downloaded the same BIOS to All cards? What is the memory of the cards?

You can not mix BIOS from differnet Cards and different Memory.