Hi guys,
Sorry if this ends up a totally noob question, but I just can grasp what's going on.
I started using Claymore's miner 10.0, mining only ethereum on ethermine.org.
The machine has 3x rx570 4gb and 1x rx470 4gb.
Everything was going fine, and it actually increased my average hashrate from 67Mh to 78Mh (reported around 83)
But then, all of a sudden, after 3 or 4 days of great use, the thing started lagging substantially. To the point of dropping connection and verry chopy hashrate chart in ethermine. A few times, I even had to hard reset the rig, because I couldn't access it via teamviewer. I tried mining with -ethi 4, and it kind of works, but hashrate is shit, and it still isn't no where near as stable as before on standard ethi setting.
What can I do to get my hashrates back?

You initial hashrate is not very good you should be getting 28+ per card so well over 100mhs
How much memory does your system have
How big is your PSU
Did you set 16 gig minimum of virtual memory
What is your operating system win 7/ win 10
Not enough information here to go on
Hi, thank you for your reply. The moment I went to bed, the problem occurred to me. The rig is in a room without ethernet installation, so it uses a Wifi dongle. I found out that the moment the graphic cards started working, they must have increased the emitted EM crap so much that the wifi became just too unstable.
So I ran down to the basement in the middle of the night with a 1m usb extension cable, and I am a happy miner ever since. Or at least until I saw today's ether price charts:)
Maybe my low hashrate has something to do with the fact that it is a headless rig, and I didn't receive the DVI dummy plug yet. Now the rx570 are giving ~24MH and the RX460 (I mistakenly wrote RX470 in my initial post) ~12MH. If I understand things right, once I plug in the dummy, the AMD drivers will load properly, and the 570s should get into the 28MH territory.
Or is there anything else I could do?