I have a RX 6600 XT running with PhoenixMiner on Ubuntu 20.04.3 with amdgpu-pro-driver-21.30.
*** 115:20 *** 12/30 20:13 **************************************
Eth: Mining ETH on ssl://eu1.ethermine.org:5555 for 95:03
Available GPUs for mining:
GPU1: ASRock Navi 23 [Radeon RX 6600/6600 XT/6600M] (pcie 45), OpenCL 2.0, 8 GB VRAM, 32 CUs
GPU1: 54C 7% 66W
GPU1: cclock 1190 MHz, cvddc 743 mV, mclock 1169 MHz, Tj 59C, Tmem 74C, 509 kH/J
GPUs power: 66.0 W; cost: 0.48 USD/day; 509 kH/J
Current -gt 15
Eth: Accepted shares 3070 (5 stales), rejected shares 0 (0 stales)
Eth: Incorrect shares 0 (0.00%), est. stales percentage 0.16%
Eth: Maximum difficulty of found share: 14.1 TH (!!!)
Eth: Average speed (5 min): 33.584 MH/s
Eth: Effective speed: 31.76 MH/s; at pool: 31.76 MH/s
At pool
Hashrate Current Average Reported Shares Valid Stale Invalid
40.6 MH/s 31.9 MH/s 33.6 MH/s 100% 34 0 0
So it seems that PM can measure up against TRM.
You show the PM stats, this are not important. And as you see - your average hashrate is 31.9, your effective pool hashrate is only 31.76!!!!! and the miner reports 33.6 = around 7% - 8% difference
Count the pool shares and compare it with TRM and you will see slightly more shares for TRM or the same, but TRM reports less but more accurated hashrate. Phönixminer inflates the reported hashrate up to 5%.
Your GPU use also to much power - reduce coreclock to 900 and vcore to 660mv and the card use 10w less.