By my observation:
An astute currency trader can make a lot more than you can mining. But you have to watch it like there is nothing else. Its not a 10m / day business.
Mining is sort of set and forget currently for me, so less income, but less hassle (maybe 1h a day of tinkering)
I have 290 cards that are mining away, say 10 or so.
They each use exactly 300w per card (measured with a kill-a-watt equivalent meter) and deliver 900hash / card
My electricity is R1,24/kwh
So my math is fairly rosy CURRENTLY, but is half the profit it would have been a month ago.
The setup cost for 10x 290 cards was R55k just for the gpu's add in PSU,MB,etc and your touching R70k
To see what I'll make in a month, remains a bit of a speculation.
In a perfect world, I would make make us$1400 profit this month from it.
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.
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We will wait and see, but I can tell you now I'll be happy if I hit half that, I don't believe in easy money, and so far I've had incredible amount of **** with my miners
Amongst other things
My 1 motherboard won't detect cards linked with 1x risers (asus maximus extreme z77)
Two of my motherboards won't boot off a Win 8 Go stick, so I had to add SSD and win8.1 copies
The 290 cards are different PER card , so lots of custom settings, no one size fits all setting
Risers - these things are the BANE of my existence. I WISH I could get 16-16 risers powered by USB. That would literally solve about 90% of my problems.
HEAT - the 290s generate 300w of heat per card. The fans are LOUD - at 80% fanspeed my cards are hitting 80 degrees easily, since its bloody 35 degrees in dbn.
Did I mention I hate customs? My risers have been stuck in customs for almost 2 weeks.
CGWatcher stalls out Win8 if cgminer closes a 290 while mining. Known bug. FUN
So 1phase home supply kinda caps around 20 gpus. Anything more and you start having fun with breakers etc.
It costs R13k in dbn to switch to 3-phase....
3phase needs special powerleads etc.... they are quite expensive
COOLING - ask @
roligov how that little garage area of his feels. These things are like heaters on steroids.
Normal aircons aren't meant to operate 24/7, so essentially you are looking at 2 units, probably 18000btu or more, running constantly.
This DOUBLES your power cost!!!
So all in all, its been a very painful learning experience.
In an ideal world I want to
Add another 40 gpus
Rise them all on USB risers
Get non reference cards for more effective cooling
Repaste most of them
Get motherboards that don't give me **** with 1x risers in 16x slots