Single gpu works fine, two of them dont

[Herculius]

Hello,

so im kinda new to mining and i have build a rig with a single gpu (as a start). I have a ASROCK H110 PRO BTC+, celeron G4900, 4gb ddr4, 240GB sdd and a vega 56 8gb.
I was mining for about a week and the hash was good (almost 1800(xmr)). Then i decided to add another vega 56 and when i did both cards were mining at 250mhs or 500mhs or even 0, sometimes one card had 0 hash and the other had a very low hash rate. I tried using different pcie lanes, some of them were like kinda laggy on the monitor. Both cards are working fine when other is disabled.

Would appreciate any help

[nordmann666]

disable CrossFire at registry AND look at Radeon Settings

and you should get more HS with other miner like SRB or JCE

[chrisbfrpky]

If you've made some changes the first thing is to make certain your hardware is still correct, especially your risers (if using risers) and your PCIE power cables. Make certain you have a power supply that will support the watts needed to run your Vega cards. There are a lot of the cheap PCIE 6+2 pin power cables on the market that are simply trash too, if your cables are yellow and black, throw them out and buy some factory type replacements from EVGA or SEASONIC. Use a multimeter and make sure your risers (again if using) are receiving power and it's also a good idea to check the power readings on your PCIE cables too. You will soon find that replacing risers (if using) becomes an all too common thing. (you probably already know all this stuff so I'm just pointing it out for anyone that doesn't)

Once you have your hardware checked out and you are sure everything is good, then look at the mining software you are using, remember when you add or remove cards you will need to edit your config file. Depending on what software you are using the method and even the name of the file you need to edit varies. You might try to add what miner you are using here or in the mining software thread with a copy/paste of your current config for a few opinions. If it's wrong for your hardware setup, I'd bet somebody would be nice enough to fix it for you and copy paste the new correct config for you.

Good Luck! Chris B.

[Herculius]

Apparently just turning of the crossfire at the radeon settings fixed it.. thanks for the help