Low hashrate on one of 8 GTX GeForce 3GB cards

I am mining RVN on a rig with 8 GTX GeForce 3GB cards. 7-th card has low hashrate, see miner log:

20210228 17:03:54 Mining at rvn.2miners.com:6060, diff: 4.29 G
20210228 17:03:54 GPU #0: MSI GTX 1060 3GB      - 9596.40 kH/s, [T:55C, P:100W, F:100%, E:97kH/W], 1/1 R:0%
20210228 17:03:54 GPU #1: MSI GTX 1060 3GB      - 9568.10 kH/s, [T:49C, P:101W, F: 98%, E:97kH/W], 6/6 R:0%
20210228 17:03:54 GPU #2: MSI GTX 1060 3GB      - 9831.48 kH/s, [T:49C, P: 96W, F:101%, E:100kH/W], 7/7 R:0%
20210228 17:03:54 GPU #3: MSI GTX 1060 3GB      - 9659.21 kH/s, [T:57C, P:100W, F:100%, E:98kH/W], 7/7 R:0%
20210228 17:03:54 GPU #4: MSI GTX 1060 3GB      - 9888.79 kH/s, [T:56C, P: 97W, F:100%, E:101kH/W], 6/6 R:0%
20210228 17:03:54 GPU #5: Gigabyte GTX 1060 3GB - 9714.99 kH/s, [T:61C, P: 99W, F:100%, E:98kH/W], 6/6 R:0%
20210228 17:03:54 GPU #6: MSI GTX 1060 3GB      - 9573.44 kH/s, [T:50C, P: 99W, F: 99%, E:97kH/W], 6/6 R:0%
20210228 17:03:54 GPU #7: Gigabyte GTX 1060 3GB - 4020.69 kH/s, [T:44C, P: 68W, F:100%, E:59kH/W], 4/4 R:0%
20210228 17:03:54 Hashrate: 71.85 MH/s, Shares/min: 1.185 (Avr. 1.089), Avr.P: 759W, Avr.E: 95kH/W
20210228 17:03:54 Uptime: 42 mins 31 secs | Algo: kawpow | T-Rex v0.19.11

it also consumes lesser power.

How to check what can cause this? What diagnostics tool can I use? How to check if the power supply is enough?

Switching to another RVN minter (t-rex, cc-enemy) and switching the cards between different PCI slots do not have a result.

root@rig0:/# nvidia-smi
Sun Feb 28 17:19:17 2021
+-----------------------------------------------------------------------------+
| NVIDIA-SMI 460.56       Driver Version: 460.56       CUDA Version: 11.2     |
|-------------------------------+----------------------+----------------------+
| GPU  Name        Persistence-M| Bus-Id        Disp.A | Volatile Uncorr. ECC |
| Fan  Temp  Perf  Pwr:Usage/Cap|         Memory-Usage | GPU-Util  Compute M. |
|                               |                      |               MIG M. |
|===============================+======================+======================|
|   0  GeForce GTX 106...  On   | 00000000:01:00.0 Off |                  N/A |
|100%   55C    P2    99W / 100W |   2850MiB /  3019MiB |    100%      Default |
|                               |                      |                  N/A |
+-------------------------------+----------------------+----------------------+
|   1  GeForce GTX 106...  On   | 00000000:02:00.0 Off |                  N/A |
| 98%   48C    P2   101W / 100W |   2850MiB /  3019MiB |    100%      Default |
|                               |                      |                  N/A |
+-------------------------------+----------------------+----------------------+
|   2  GeForce GTX 106...  On   | 00000000:03:00.0 Off |                  N/A |
|100%   49C    P2    95W / 100W |   2850MiB /  3019MiB |    100%      Default |
|                               |                      |                  N/A |
+-------------------------------+----------------------+----------------------+
|   3  GeForce GTX 106...  On   | 00000000:05:00.0 Off |                  N/A |
|100%   57C    P2   100W / 100W |   2850MiB /  3019MiB |    100%      Default |
|                               |                      |                  N/A |
+-------------------------------+----------------------+----------------------+
|   4  GeForce GTX 106...  On   | 00000000:06:00.0 Off |                  N/A |
|101%   56C    P2    99W / 100W |   2850MiB /  3019MiB |    100%      Default |
|                               |                      |                  N/A |
+-------------------------------+----------------------+----------------------+
|   5  GeForce GTX 106...  On   | 00000000:07:00.0 Off |                  N/A |
|100%   60C    P2    98W / 100W |   2850MiB /  3019MiB |    100%      Default |
|                               |                      |                  N/A |
+-------------------------------+----------------------+----------------------+
|   6  GeForce GTX 106...  On   | 00000000:08:00.0 Off |                  N/A |
| 99%   50C    P2    97W / 100W |   2850MiB /  3019MiB |    100%      Default |
|                               |                      |                  N/A |
+-------------------------------+----------------------+----------------------+
|   7  GeForce GTX 106...  On   | 00000000:0A:00.0 Off |                  N/A |
|100%   44C    P2    68W / 100W |   2850MiB /  3019MiB |    100%      Default |
|                               |                      |                  N/A |
+-------------------------------+----------------------+----------------------+

+-----------------------------------------------------------------------------+
| Processes:                                                                  |
|  GPU   GI   CI        PID   Type   Process name                  GPU Memory |
|        ID   ID                                                   Usage      |
|=============================================================================|
|    0   N/A  N/A      2181      G   /usr/lib/xorg/Xorg                  6MiB |
|    0   N/A  N/A      5352      C   t-rex                            2839MiB |
|    1   N/A  N/A      2181      G   /usr/lib/xorg/Xorg                  6MiB |
|    1   N/A  N/A      5352      C   t-rex                            2839MiB |
|    2   N/A  N/A      2181      G   /usr/lib/xorg/Xorg                  6MiB |
|    2   N/A  N/A      5352      C   t-rex                            2839MiB |
|    3   N/A  N/A      2181      G   /usr/lib/xorg/Xorg                  6MiB |
|    3   N/A  N/A      5352      C   t-rex                            2839MiB |
|    4   N/A  N/A      2181      G   /usr/lib/xorg/Xorg                  6MiB |
|    4   N/A  N/A      5352      C   t-rex                            2839MiB |
|    5   N/A  N/A      2181      G   /usr/lib/xorg/Xorg                  6MiB |
|    5   N/A  N/A      5352      C   t-rex                            2839MiB |
|    6   N/A  N/A      2181      G   /usr/lib/xorg/Xorg                  6MiB |
|    6   N/A  N/A      5352      C   t-rex                            2839MiB |
|    7   N/A  N/A      2181      G   /usr/lib/xorg/Xorg                  6MiB |
|    7   N/A  N/A      5352      C   t-rex                            2839MiB |
+-----------------------------------------------------------------------------+

I did apt dist-upgrade and nvidia-driver-update, but with no result.