R9 280X drops in Hashrate after 4 GPU's

Mining Mining Support
1

Hello fellow miners …

I saw the other thread but the answer is not answered.

I have 8 R9 280X cards and an Asrock H110 PRO BTC.

I have 2 power supplies with 1800 watt in total.

With 4 cards i gor about 1100 Sols and after putting in the 5th card i got 150 sols per card.

tried overclock but there is no change.

I use simpleminingOS because this setup with Windows is giving problems.

Who can help me.

Thanks in advance

Greetings Justbitcoinz

2

The cards went from 250 - 270 a card with 4 and 130 - 150 with one card more … Somebody know ?

3

Are they all the same card or set to same clocks?

4

@Justbitcoinz

Can you detail what BIOS changes, if any, you have already made? My first suspicion is that you may need to adjust the PCI max speed to a lower generation setting, but I’d like to know what you’ve done already.