So I have been mining for only a DAY or so now. But I have been studying up on this topic of mining all day as I was waiting for my parts. I have 2 GPU's: RX 470 4 GB Samsung memory and R9 390 8GB. I am using Claymore's miner with the recommended drivers on Nanopool. It only isn't until now, after I have been mining for a short amount of time that I am realizing a few things.
GPU stability matters more than hash rate. I learned this when I immediately flashed my RX 470 BIOS using a few tutorials on YouTube. Stock rate was ~20-22 mh/s. After flashing and clocking, I got 28 mh/s. However, the card wasn't stable. Often I'd get prompts on Claymore's miner that my RX 470 received an incorrect allocation of shares (or something to that nature). It happened once or twice every five minutes or so, and I noticed that as it happened, it seemed to slow down my mining. Also, the Claymore miner would go down every while or so (not sure why). Long story short, I re-flashed stock BIOS, bricked it, used the "8 plus 1" (look it up) to short circuit the GPU chip and re-flash the stock BIOS. Now I am mining at a stable ~20-22 mh/s again and the card is very stable. I left the 2 GPU rig on overnight and woke up to it still going. The RX 470 finds a share every so often.
My R9 390 8GB is a beast. Even though its old, has a relatively low stock hash rate (28-31 mh/s), eats up a gang of wattage, it's finding a lot of accepted shares. I'd say 3x what the RX 470 is finding. Again, running stock BIOS and nearly stock clocking. It is pretty unstable on my rig with any type of overclocking, it might be the driver and the fact that I'm running my monitor off it.
In all, I am hashing at a combined rate of ~49-52 mh/s and according to the 2 hour simple moving average (SMA) on Nanopool, I have an calculated hash rate of ~49-50 mh/s. Note that calculated hash rate is what matters, not your reported hash rate. You may be hashing along at 50 mh/s, but due to your rig's instability, you may not have many accepted shares and have low mining efficiency.
I'd like to know your experiences with hashing, BIOS flashing and clocking. Are you achieving stability? Is your rig unstable and still finding accepted shares? Did you flash the crap out of your BIOS and still achieving a high calculated hash rate? Please share. Thanks!
