Author Topic: Old cards and hash rates  (Read 174 times)

NilMag

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Old cards and hash rates
« on: August 30, 2017, 09:16:19 pm »
Hi all
Started mining again today after a couple years absence.

Mining with 2x 780 on water. cards at 36C with 22C inlet temp for the radiators and 26 on the water.
Getting 2,445-2,500 on both cards, is that what i can expect, I'am at -x 24 any higher and the rates drop 0,1. Anything to gain with using more of mem?
x24 puts me at 68% gpu mem usage, x32 86% Its a bit weird also, only 75%tdp with 99% gpu load ?

Also, wil I find anything with those rates?

/NilMag

moonstruck

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Re: Old cards and hash rates
« Reply #1 on: September 01, 2017, 10:44:14 am »
You'll have to play a bit with intensity, I see local maximums when searching for the actual maximum, it's easier when you make a graph with the results. 2500MH/s sounds about right though. I don't know how memory usage or clocks play a role in older cards, you'll have to tweak and see.

A 780 uses about 190W at 75% tdp.
calculating at 0,20$/kWh:
1 block/minute x 60 minutes/hour x 24 hours/day x ~4coins per block x (your hashrate / global hashrate) = X coins per day per card
60x24x~4x(2,5/35000)=0,41 coins per day per card = 0,82 coins per day for 2 cards.
This will amount to $2,28 per day on average at current prices.
It will take however on average 4,75 days to find a block, it is even very well possible to not mine anything for 2 weeks!
On the other hand you might get lucky and mine 5 blocks in a day but it is unlikely.

Your energy will cost:
(((power of cards + power of other hardware)/efficiency)/1000 [W -> kW])*24 hours*energy cost
(((190+190+120)/0,85)/1000)*24*0,20=2,82$ per day.

So you'd be running a loss of $0,54 per day on average. If you pay less for energy you might hit break even or even make a little profit.
Your profits will depend greatly on your luck though if you don't join a pool. Joining a pool will result in even less income on average but will even out profits.
Price is also at a high point right now, if it lowers your loss will increase as well.