Bitcoin Forum

I didn't know much of anything about Bitcoins and crypto coin mining until about a week ago. Like most people, I'd heard the term thrown around a few times and stumbled across the occasional magazine or blog article, but never gave the subject much thought beyond the casual awareness I had of its existence. That all changed about a week ago when a segment on my evening news piqued my interest. The more I looked into Bitcoin (and other alt crypto currencies), the more fascinated I became.

Jump to a week later, and I've built myself about 10 Ghash/s of mining power. I built my first rig with 4x XFX 7970 Black editions, which I quickly learned were poor performers for Litecoin mining. I then decided to purchase 12x Sapphire HD7950 Boost cards to make three more rigs. I've been much happier with these cards, as they consistently produce 650 Mhash/s when Scrypt mining.

So my current setup consists of 4x 7970s and 12x 7950s. Fortunately, I manage a family-owned business, and I am able to put these rigs in our climate-controlled server room to keep them cool and avoid electricity costs.

I'm also currently working on upgrading a number of workstations at our business. I'm building about 20 new workstations, and I'm planning in incorporating a single Radeon graphics card in each workstation. I will then install a program that starts mining during hours when the office is closed or when idle. I'm looking for a video card that will run around 400 Mhash/s for the absolute lowest cost possible. Can anyone recommend me a cost-effective card to meet my goal? The 7870 seems like a good option but it's a little pricey. I'm trying to keep the cost per card < $150. Also, if anyone knows a better place than Newegg or that offers a volume discount for 20 cards, please let me know. I hope to add another 6 GHash/s to my capacity with these workstations mining overnight.

Here's a couple pictures of three of my mining rigs (the fourth is at home). I built them before I found this forum, so I didn't have the advantage of seeing all the awesome design ideas prior to putting these together. I simply used DIY-PC test benches from Newegg and I think they came out pretty well. Questions / comments / criticisms welcomed.

http://i799.photobucket.com/albums/yy271/cvalk/IMG_20130614_121002_158_zpsa2aae9c7.jpg (http://s799.photobucket.com/user/cvalk/media/IMG_20130614_121002_158_zpsa2aae9c7.jpg.html)

http://i799.photobucket.com/albums/yy271/cvalk/IMG_20130614_120944_519_zps0182af4f.jpg (http://s799.photobucket.com/user/cvalk/media/IMG_20130614_120944_519_zps0182af4f.jpg.html)

Here's how the 7950 rigs run at 1090/1625. BIOS flash to lock the voltage at 1.09v.
http://i799.photobucket.com/albums/yy271/cvalk/Untitled_zpse66a341e.jpg (http://s799.photobucket.com/user/cvalk/media/Untitled_zpse66a341e.jpg.html)

If anyone has any suggestions regarding strategies on what to mine and when, I'm all ears. I'm currently using all 4 rigs to mine Litecoin, but I'm thinking of switching the 7970's to Bitcoin since they suck with scrypt. Is it worth mining Bitcoin with just 2.8 Ghash/s? Another option I considered was using 3 rigs to mine a primary currency (Litecoin at the moment) and the 4th to switch between alt cryptos and mine new cryptos at low difficulty to accumulate a diverse portfolio. Anyone utilize a similar strategy?

I'm happy to have found this great resource and I've learned a ton on here already. Looking forward to being a part of the discussion and helping out others when I can.

Nice rigs you have there but i think you should start
buying asics instead of more gpus.  :P

4000+ rpm on fans? Not afraid of wearing them out?

Thanks. I'd love to get my hands on an ASIC but as you know the waiting lists are long at this point and many of them may be vaporware. I can't justify that kind of investment when I don't know if / when I'll receive my hardware and if it'll even be profitable by the time it's received. I could go buy a bunch of Block Eruptor USB ASICs but they're >=$1/Mhash and while a 7950 is <= $0.50/Mhash. Since I'm not paying for electricity, I still feel that GPUs are the way to go at the moment. I'm still very new to this, so if my logic is flawed, please let me know.


I haven't done enough research to know if that should be a concern. I figured if they wore out I could always replace them. Is there an RPM that is regarded as a safe limit? None of my GPUs use auto fan, voltage, or clockspeed control. All values are manually entered and run at those settings 24/7.

Efficiency: 1085%  ;D

Thanks for putting up the photos, it look impressive. Hope it goes well!

those are pretty impressive results and nice photos within a really short amount of time, I mean, having just learned about bitcoin mining a week ago, and seeing your rigs now - it seems that you could readily translate all the info into actions rather quickly, kudos - good job!

free electricity and cooling are obviously great assets, so I wouldn't worry about ASICS for now - if you have the power, cooling and space, you can certainly keep on adding GPU-based mining hardware. You may however want to look into using Linux instead of Windows, because that should allow you to more easily manage clusters of dedicated headless mining hardware, without necessarily requiring a screen, keyboard, mouse or even a full GUI - normally, you would only really need 1-2gb of RAM, because all the number-crunching should be handled through the GPU and its dedicated VRAM.

Great rig, Hope I could build like this soon.

I commend you on your rig.

join a pool and see for yourself after 3-4 weeks. Depending on how much hardware you'll be able to throw at this, people may even team-up with you - at least you seem to be legit, unlike most people/scammers here  :)

sweet

how much money u make

Nice rigs you have. But 20 new workstantion will warm the room.

awesome

Good  :)

I'd say you'd make about $12.00 a day at Slush's pool with 2.8 Ghash/s at the moment. A couple of weeks ago it would have been significantly higher but the new difficulty together with the growing ASIC presence and the recent decline in BTC to fiat price mean the numbers have been falling steadily. The graphics card mining era really is almost over for BTC, I think, unless the fiat exchange value of BTC climbs substantially - you never know. I'm not in this for fiat though.     :)

Nice rigs and a super first post, OP.

they look impressive mate

Thanks for the insight. I've been tempted to play around with Linux for years but never felt like starting over and learning a new OS. The reasons you mentioned are pretty strong incentives and I think I'll give it a try.


Thanks for the kind words. During the short time I've been browsing this forum, I've been absolutely amazed at the overwhelming number of bottom feeders and scam artitst on here. I guess it's inevitable when dealing with a digital currency. Thank you for not counting me as being among them. The idea of teaming up and pooling resources is certainly something to consider going forward.


Thank you. You're right, twenty workstations would turn that room into a sauna. Fortunately, they will be spread out and all in different offices, so it shouldn't be a problem.


Thank for for the kind words and the insight. The more I learn about crypto currencies and mining, the more I want to kick myself for not getting into it sooner! Still, $12/day is better than nothing and certainly worth doing. I'm bullish on Bitcoin and the potential for future growth is more appealing to me than a daily profit figure at this point. I'll give it a try.


Everyone else, thank you for the compliments.

note that you can start your own pool and even sell shares through bitfunder.com to get some funding for bootstrapping

purdy