Litecoin build for noobs: 3x 7950s (1.8 MH/s) in a $10 crate case

[kokojie]

Ok, bought 12 sapphires, and 3 of everything else. Going to add another mobo and fixing asap. So I will start running 3 rigs with 4 cards each, and will thin them to 4 rigs ASAP.
Noob questions begin here.
1. How do I run the 4 gpus off the mobo listed? Can anyone provide a link to the required extra gear or cables needed. I did upgrade the psu to 1000's already btw

2. How do I clone the harddrives for mining?

3. I got long risers which will space the gpu's no less than 6" apart in a fan like set up, space is not a concern for me. Will this provide adequate cooling space for the 4 gpu on 1 mobo set up in the beginning?

Any tips and suggestions would be great.
Thanks!

iam not sure if 4x 7950 will work stable with a 1000psu. it will depend on the corevoltage of each card.

i got 2x gigabyte7950, this version is overclocked out of the box with a locked corevoltage of 1,25. each card pulls about 320W, so 4x them would be too much for a 1000w psu

Which gigabyte GPU? I'm running 4x gigabyte 7950 windforce, on a 1200W PSU with no problem, I didn't under-volt. They each only pull 200W barely, probably less. How can a 7950 pull 320W? I hope your 7950 better mine at 1000kh or something. Though you are right, 4x7950 on a 1000W most likely will not work, since PSU only work at 80% efficiency. So that 1000W is only capable of giving you 800W actual power, 4x7950 will eat that up, leaving nearly zero power for other components.

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[GForce]

I wish I had some money to buy graphics cards

[mrspencer]

The cynic part of me think BTC is there to sell AMD GPU. 

[Starlightbreaker]

Ok, bought 12 sapphires, and 3 of everything else. Going to add another mobo and fixing asap. So I will start running 3 rigs with 4 cards each, and will thin them to 4 rigs ASAP.
Noob questions begin here.
1. How do I run the 4 gpus off the mobo listed? Can anyone provide a link to the required extra gear or cables needed. I did upgrade the psu to 1000's already btw

2. How do I clone the harddrives for mining?

3. I got long risers which will space the gpu's no less than 6" apart in a fan like set up, space is not a concern for me. Will this provide adequate cooling space for the 4 gpu on 1 mobo set up in the beginning?

Any tips and suggestions would be great.
Thanks!

iam not sure if 4x 7950 will work stable with a 1000psu. it will depend on the corevoltage of each card.

i got 2x gigabyte7950, this version is overclocked out of the box with a locked corevoltage of 1,25. each card pulls about 320W, so 4x them would be too much for a 1000w psu

Which gigabyte GPU? I'm running 4x gigabyte 7950 windforce, on a 1200W PSU with no problem, I didn't under-volt. They each only pull 200W barely, probably less. How can a 7950 pull 320W? I hope your 7950 better mine at 1000kh or something. Though you are right, 4x7950 on a 1000W most likely will not work, since PSU only work at 80% efficiency. So that 1000W is only capable of giving you 800W actual power, 4x7950 will eat that up, leaving nearly zero power for other components.

my 850w psu pulled 1100 from the wall.

still not burnt out yet, which is good. i'm looking forward for my new psu.

in the mean time, i need to find the most efficient setting.

[kokojie]

The cynic part of me think BTC is there to sell AMD GPU.  

naw, look at AMD stock, it's crash and burn. Believe it or not, mining is only tiny portion of AMD profits, plus most of the profit is earned by the manufacturers (msi, sapphire, gigabyte etc...). AMD makes shit margins on the chip.

[destruct]

Anyone figure out the sweet spot for good kh/s rate for Sapphire 7950's ?

I've got 5 cards running at 1025/1480 -- default voltage with +10% power (won't stay in high performance mode if I don't add the 10%) but my overall hash rate is only 2.6 Mh/s but many are saying they get 700kh/s(3.5Mh/s) with their 7950's

Any help is greatly appreciated.

[pro]

Ok, bought 12 sapphires, and 3 of everything else. Going to add another mobo and fixing asap. So I will start running 3 rigs with 4 cards each, and will thin them to 4 rigs ASAP.
Noob questions begin here.
1. How do I run the 4 gpus off the mobo listed? Can anyone provide a link to the required extra gear or cables needed. I did upgrade the psu to 1000's already btw

2. How do I clone the harddrives for mining?

3. I got long risers which will space the gpu's no less than 6" apart in a fan like set up, space is not a concern for me. Will this provide adequate cooling space for the 4 gpu on 1 mobo set up in the beginning?

Any tips and suggestions would be great.
Thanks!

iam not sure if 4x 7950 will work stable with a 1000psu. it will depend on the corevoltage of each card.

i got 2x gigabyte7950, this version is overclocked out of the box with a locked corevoltage of 1,25. each card pulls about 320W, so 4x them would be too much for a 1000w psu

Which gigabyte GPU? I'm running 4x gigabyte 7950 windforce, on a 1200W PSU with no problem, I didn't under-volt. They each only pull 200W barely, probably less. How can a 7950 pull 320W? I hope your 7950 better mine at 1000kh or something. Though you are right, 4x7950 on a 1000W most likely will not work, since PSU only work at 80% efficiency. So that 1000W is only capable of giving you 800W actual power, 4x7950 will eat that up, leaving nearly zero power for other components.

i got this one: http://geizhals.at/eu/gigabyte-radeon-hd-7950-gv-r795wf3-3gd-a732249.html. i got 2 of it + an i5 + 1 ssd . this setup takes 580W under full load, according to my wattmeter. so my guessing of 320W was bit overrated. cpu+ ssd cant take more than 50W. so each card pull about 260W.

as u said 4 would be too much, 3 will work fine with a 1000W

[ronaldinho_07]

here's one of my rig 4x5850 
Used case ~ 2.5$
4 riser 1x->16x ~ 20$
Giga P31+2GB ddr2+Dual E3300 ~ 50$ (all used)
Corsair TX750 new ~ 120$
4x 5850 ~  440$,all of them are under warranty

all cost ~ 630$
with this rig,i can get about 1.5-1.6Mhash when mining ltc 

[Marrs]

my 850w psu pulled 1100 from the wall.

still not burnt out yet, which is good. i'm looking forward for my new psu.

in the mean time, i need to find the most efficient setting.

An 850W pulling 1100W from the wall is about right for an 80% efficiency power supply running at full capacity.

850 / 0.8 = 1062.5

What that means is, your system is drawing 850 watts, and your power supply is losing 20% of it to heat. Replacing your PSU with  an 80+ platinum would reduce your at-the-wall draw to around 950W.

[kokojie]

here's one of my rig 4x5850 
Used case ~ 2.5$
4 riser 1x->16x ~ 20$
Giga P31+2GB ddr2+Dual E3300 ~ 50$ (all used)
Corsair TX750 new ~ 120$
4x 5850 ~  440$,all of them are under warranty

all cost ~ 630$
with this rig,i can get about 1.5-1.6Mhash when mining ltc 

I like the dangling hard drive. Though I find it hard to believe a 750W PSU can power 4x 5850, must be terribly overloaded, I think it's pretty risky.

[ronaldinho_07]

nope,it's all ok  .it has been running for a month without restarting or hanging
with stock voltage,i set 900/1000mhz(core/mem) ~ 380Khash each
or lower clock,at 850/800 ~ 360Khash
you can undervoltage by using "--gpu-vddc" in cgminer

[AmDD]

I wish I could get the hash rates I see from some of you out of my rigs!

Ive got two rigs with 5850's, each getting about 320kh/s.
I also just built a rig similar to what this thread talks about, 3 7950's, each getting 500-520kh/s.

Either Im doing something wrong or just unlucky :/

[Starlightbreaker]

my 850w psu pulled 1100 from the wall.

still not burnt out yet, which is good. i'm looking forward for my new psu.

in the mean time, i need to find the most efficient setting.

An 850W pulling 1100W from the wall is about right for an 80% efficiency power supply running at full capacity.

850 / 0.8 = 1062.5

What that means is, your system is drawing 850 watts, and your power supply is losing 20% of it to heat. Replacing your PSU with  an 80+ platinum would reduce your at-the-wall draw to around 950W.

...aaaand i forgot about the efficiency & power factor.

i got nervous when it spiked to 1300, but eh.

[ronaldinho_07]

I wish I could get the hash rates I see from some of you out of my rigs!

Ive got two rigs with 5850's, each getting about 320kh/s.
I also just built a rig similar to what this thread talks about, 3 7950's, each getting 500-520kh/s.

Either Im doing something wrong or just unlucky :/

here's my setting with 5850 rig : cgminer --scrypt --thread-concurrency 5760 -I 18 -g 1 -w 256
windows 7 32 or 64b,ccc 12.6 (you may install only amd driver without ccc) and sdk 2.6

[BaghdadSteve]

Considering picking up two 7950s next week.  Would it be better to run them in Crossfire or no?

[TheAce]

again pls can yanyone share software setup ? is important to have 64bit win? or just any win and guiminner and u can mine?

[the_crown]

any alternatives for the vinyl pads? are all of you putting something under your mobo at the bottom of the crate?

[AmDD]

I wish I could get the hash rates I see from some of you out of my rigs!

Ive got two rigs with 5850's, each getting about 320kh/s.
I also just built a rig similar to what this thread talks about, 3 7950's, each getting 500-520kh/s.

Either Im doing something wrong or just unlucky :/

here's my setting with 5850 rig : cgminer --scrypt --thread-concurrency 5760 -I 18 -g 1 -w 256
windows 7 32 or 64b,ccc 12.6 (you may install only amd driver without ccc) and sdk 2.6

My 5850's run linux (BAMT with updated drivers for 7xxx cards, unsure exactly what drivers tho) so those settings did not give me any boost.

[tacotime]

Hey, trying to stay out of here for a bit, but someone brought these cards to my attention and I thought you guys might want to know about them if you're still building rigs

http://www.newegg.com/Product/Product.aspx?Item=N82E16814202030
http://www.newegg.com/Product/Product.aspx?Item=N82E16814202031

They are AMD 7970 reference boards and thus have really solid voltage regulation and RAM, VRMs are all really well cooled.  As such they should all also have voltage control.  Once these go out of stock they will likely not be replaced, so grab them while they're still around.

edit: voltage control confirmed with sapphire trixx http://www.overclock.net/t/1378557/sapphire-100352-4l-and-21196-00-20ghd-7950-the-final-holy-grail-of-hd7950s

[offbyone]

Hey, trying to stay out of here for a bit, but someone brought these cards to my attention and I thought you guys might want to know about them if you're still building rigs

http://www.newegg.com/Product/Product.aspx?Item=N82E16814202030
http://www.newegg.com/Product/Product.aspx?Item=N82E16814202031

They are AMD 7970 reference boards and thus have really solid voltage regulation and RAM, VRMs are all really well cooled.  As such they should all also have voltage control.  Once these go out of stock they will likely not be replaced, so grab them while they're still around.

edit: voltage control confirmed with sapphire trixx http://www.overclock.net/t/1378557/sapphire-100352-4l-and-21196-00-20ghd-7950-the-final-holy-grail-of-hd7950s

I picked up one N82E16814202030 and it does have proper voltage control and beastly capability. I paid $299 for it. If pushed, it can do 600 kH/s or 580 comfortably.