Bitcoin Forum

Hi guys, i finally ordered all the parts! Everything should get here by friday, havent built a pc in years now so i am a bit rusty and need some help specifically with bitcoin tuning.  (i tried to buy pre-built from cyberpowerpc but it turned into an epic saga, story for another time).

Anyway here is what i ordered:

2x refurbished Visiontek HD 5970
Cooler Master Silent Pro Modular 1000W 80 PLUS Bronze Certified Power Supply
AMD Phenom II X2 555 Black Edition Callisto 3.2 GHz (yes i know waste of money but it's the cheapest cpu amazon has)
ASRock AM3 processors AMD 770-140W 4DDR3/ATI CrossFireX motherboard M3A770DE
2GB ddr3 value ram and some cheap hdd.
MYOPENPC BENCH King Transparent Black Acrylic Test Bench Case

This will be a dedicated bitcoin rig running windows 7 with gui miner.

1) I understand i need to disable crossfire and run the gfx cards separately, how do i do that after plug the cards into the mobo slot?
2) Based on my hardware do you see any problems with this setup? am i missing anything?
3) Can someone explain in baby steps how to overclock the 5970 specifically for bitcoin mining? From my search MSI afterburner seem to be the weapon of choice and memory overclock is not needed. But what settings should change for the 5970, i want to remain on the conservative safe side and prefer not to mess with the voltage core.

I have a completely open case(if you call it that) and plan to put a room fan blowing directly at it. Hopefully it will not turn into the next chernobyl incident...

thanks!

Where did you find two 5970s?!?

what you mean? they are everywhere on ebay...

I am curious to see how you calculated mining profitability. Assuming an average 50% increase in difficulty every 10 days, and 15 cents per kWh electricity cost, you would make about $130 the first 10 days, $77 the second, $40 the third, and down from there (before exchange fees, and assuming $15/BTC, and OC'd to 750 Mh/s per GPU, which is on the higher end).

i didnt mean this thread to go into a p&l analysis  :D but yeah you are right it's a money loser unless bitcoin gaps up.  Not really doing this purely to make money. I just like the whole concept of p2p currency and mining. ( i am a miner in eve online too, and also wow although that sucked).  So instead of going to mtgox and get hacked to buy coins, i will just mine them myself and keep it for 10+ years and see what happens.

anyway can someone answer my original questions :/  dont worry i won't quit my day job.

EDIT: forgot to mention once i get the rig stable, will just dump it in my buddy's warehouse and remote into it, there is no way i can leave this vacuum heater on 24/7 at my apt. So electricity used is really not a factor.

1) I understand i need to disable crossfire and run the gfx cards separately, how do i do that after plug the cards into the mobo slot?

Dont connect the bridge. It will want you to hook up a monitor to each card. Either do that, or slap a dummy plug into card number 2. Either will work. You dont have to disable crossfire, just dont connect the xfire bridge.


2) Based on my hardware do you see any problems with this setup? am i missing anything?

Looks OK to me. Case might not get you enough airflow though, you may run into some temperature issues. Leave it as open as you can without the hardware being uneccesarily prone to dust/damage/exposure dending on the environment in the warehouse. You could have gone with a less expensive CPU as well, but you're fine with that one.


3) Can someone explain in baby steps how to overclock the 5970 specifically for bitcoin mining? From my search MSI afterburner seem to be the weapon of choice and memory overclock is not needed. But what settings should change for the 5970, i want to remain on the conservative safe side and prefer not to mess with the voltage core.

Easy. Install afterburner (free from MSI's website). Clock the memory all the way down right off the bat. SLowly increase your core clock on the first card and test for stability. Rinse and repeat till youre comfortable. Do the same for card 2.

Walk in the park.

Oh, one more thing. Before you leave, check cpu usage in task manager (assuming youre using Windows). You'll probably wanna set affinity all to one core for your miners, since when using dual cards it likes to eat up CPU power. Unnecessary electricity, right there. Setting the affinity all to one core seems to be the only way around that. Annoying, but no big deal.

Given that you accept that mining will not have a pay-back at current bitcoin exchange prices, I offer that you might enjoy learning about Linux with your mining rig.  The linuxcoin OS boots from a 2GB USB memory stick and you do not need a hard drive.  The linuxcoin forum thread is very active - perhaps you can configure a dual-boot after you get Windows running to your satisfaction.

chihlidog, thanks! that was very helpful and to the point. I will give it a whirl this weekend.  Yeah i spent almost half hour trying to find the right case, the biggest problem is the length of those 5970 are too long for most mid tower, and those that will fit both all cost $200+ which doesnt make sense since i am just using it as a mining rig.  Full tower are just too big/heavy and also not cheap either. So this really seem to be the only option - cheap, light, fit boths cards and well ventilated. I will get a powerful table fan and just blow directly at the graphic cards. Only downside as you said is the hardware are exposed to dust, i will try to find a good place for it.


I really dont see much performance gain going linux though, with windows 7 i can be up and running literally in minutes with guiminer. Although i use redhat at work for java/j2ee development and got a few dedicated vps accounts to play around with (checkout linode.com very good vps with full root ), I am not a SA so the security aspect always seem to bother me simply because i dont know well enough. Although windows 7 is not as secure i am much more confident with its security.  

NP. It shouldnt give you any trouble at all. Good luck. Im a little jealous, thats a great mining rig.

Hi guys, I finally got everything up and running now, tried guiminer with fresh install of windows 7 64bit + AMD APP (formerly Stream) SDK

1) In the guiminer device dropdown I see: 0-0 cypress,  0-1 cypress, and 0-2 amd phenom.  Does 0-0 cypress and 0-1 cypress mean two cores on the SAME card, or does it mean two cards?  If it's 2 cores on the same card, that means my 2nd card isnt active (i used a dvi/vga without the resistor mod).  This is confusing, also how do i run both 0-0 and -01? do i need to start up two separate instances of guiminer?  Also once my 2nd card is found, that means i have to start up 4 instances of guiminer?

2) I am getting 250 mhash/sec right now lol, obviously something is horribly wrong.  Do i need to download the driver in addition to ADM APP SDK?  with the -v -w128 option it went up to 300mhash/sec  :-\

Hopefully it's just a driver issue.  What do you guys usually do after a fresh install of windows 7? install ADM APP SDK, install driver?

thanks

Hey 0-0 and 0-1 that means two cards, u need 2 workers (one worker for graphic card)
But tell me one thing u just connected two cards to dvi/vga monitor and worked?
I have the same board but i cant active the second card in orange slot X4.