Hi I have a Rig with 8 cards. One of them is AMD and the others are NVidia. I have 3 3090 cards, one of them is MSI, other Zotac Trinity and the other is Gigabyte.
The MSI card is reporting 106 MH/s withouth overclocking but the other 2 have a lower Hashrate. Zotac is reporting 74 MH/S and Gigabyte is reporting 59 MH/s.
I made some changes on overclocking in this cards but it never goes up. These cards are new maybe i bought them 1 or 2 months ago.
I am using phoenix miner and i was using this with windows 10 and cards were reporting a better hashrate but lower than 100 MH.
Running cards without proper clocks is just going to kill the cards sooner and waste power.
Find the highest memory that is stable for each card, and the lowest core clock that maintains full hashrate. Use locked core clocks on the 30 series cards, that will help reduce power draw to only what is needed. On the 10 series you can only use offsets for core clock and if you want to reduce power beyond that set a power limit.
Target hashrates for your 6800 would be 62mh around 115w and for the 3090s 125mh at 300w. Some cards will take a little more and some will take a little less.
Default clocks are good for gaming, terrible for mining.
