Is it normal to have 600H then drops to 30H then back to 600? The hashrate refreshes only about twice/minute so I'm not sure for how long those drops actually happen. Anyone share their scores ? I have i5 2500k 4.4ghz 535h 3core, 680h 4core but bigger drops.
When blocks come in or threads handoff speed can drop for a few seconds or so. UI updates every 30 seconds so it can seem longer but isn't. Look at your processor usage to confirm.