3080 FE overclocking memory fail + actual hashrates

[channie]

Hi all,
Didnt want to track 2 topics as theyre kind of linked.
I’m new to mining and been up and running for 3 days.

On the first day I tried overclocking, but everytime I would set the memory clock to anything other than default it would cause CUDA errors saying to change the overclocking (something along those lines) on TRex and Phoenix miners (havent tried others) I was setting the core to -200 and memory at variations between 2000 and 2600
Can the 3080 actually be overclocked? Every video I’ve seen indicates yes, but using any of those settings seems to cause an error.

I left the overclocking alone apart from fixing the core speed to save power and was happy with the apparently consistent 87.7 MH/s reported by TRex and HiveOS

But then I went onto https://ethermine.org/ and it seems to tell a different story

[channie]

As you can see its all over the place, the miner is constantly reporting a hasrate but its largely different to what ethermine is actually seeing. Is this normal behaviour?

Cheers in advance (had to doubled post as only one image allowed for a noob)