Dual ATI Radeon HD 6990 setup

Gullanian · 7 Jun 2011 at 16:51

Hi guys,

I'm considering buying a setup for number crunching on the GPU, a bit of research shows me that HD 6990 are best for number crunching in my case.

The PC will not be used for anything else. Everything else has to be as small a cost as possible. Can anyone suggest parts for me? What bottlenecks do I need to watch out for?

So I'm building this a weird way round, I'm starting with 2 HD 6990's!

Thanks for your help

Tom

scrlk · 7 Jun 2011 at 16:56

Heat and noise will be a major problem. Thought about watercooling?

Gullanian · 7 Jun 2011 at 17:00

Never installed water cooling before, but I have a friend who does it a lot who could help.

Noise isn't a problem, I have a spare room to put it in. There is the possibility I might be running more of these machines as well.

At room temp with a decent case, how much of a risk is this cooling problem?

scrlk · 7 Jun 2011 at 18:12

Gullanian said:
Never installed water cooling before, but I have a friend who does it a lot who could help.

Noise isn't a problem, I have a spare room to put it in. There is the possibility I might be running more of these machines as well.

At room temp with a decent case, how much of a risk is this cooling problem?

This also depends on your board as ones with a slot between the 2 will have better temps. Even then, I'd presume it will still get pretty toasty. If you don't mind some maintenance, but want less noise and cooler cards, then watercooling is an option.

Tonester007 · 7 Jun 2011 at 20:36

Gullanian said:
... I'm starting with 2 HD 6990's!

My first thought was - you're going to need a beast of a PSU :eek:

This review of 6990 CF used a 1200 Watt Corsair.

Surveyor · 7 Jun 2011 at 20:45

Tonester007 said:
My first thought was - you're going to need a beast of a PSU
This review of 6990 CF used a 1200 Watt Corsair.

They would certainly use a lot of power:

HIS Radeon HD 6990 Crossfire review

At 900W it would cost over £3 a day in electricity if used for the full 24 hours.

At least you could turn the central heating off in winter.

Defunkt · 7 Jun 2011 at 21:06

i hope those numbers are worth crunching. G/L

raikesi · 7 Jun 2011 at 21:10

what number crunching are you doing?

Buchanan0204 · 7 Jun 2011 at 21:44

That's what I want to know. What's number crunching?

Gullanian · 7 Jun 2011 at 22:40

Hi guys thanks for the info, it's mining bitcoins, I've talked to a few more people, run some more numbers and unfortunately it's going to be too risky of an investment at this late stage in the difficulty. Unfortunately hardware prices in the UK are just too expensive comparatively, and the same with electricity. I was considering raising some capital really quickly and buying 3-4 of these machines to get set up this week.

http://www.alloscomp.com/bitcoin/calculator.php

With 1440 megahash p/s (roughly the rate of 2x6990) it would yield around $50 a day at current prices, minus $8 electricity (£3+other hw) would mean $42 a day. The setup is going to cost >£1k just for the cards, probably another £500 to get it going. So ~£25 a day would take 60 days to break even, if the BC to USD exchange rate of $20usd/bc remains relatively stable (no big drops).

Also the difficulty level is rising very fast. I've been told I've missed the boat pretty much. If I had one of these cards or a comparable one I'd be mining with it. My 5570 (I think!) can crunch 10% those speeds, = $5 daily, just not enough to be worth it. Requires serious GPU power.

m3sSh3aD · 16 Jun 2011 at 22:14

Gullanian said:
Hi guys thanks for the info, it's mining bitcoins, I've talked to a few more people, run some more numbers and unfortunately it's going to be too risky of an investment at this late stage in the difficulty. Unfortunately hardware prices in the UK are just too expensive comparatively, and the same with electricity. I was considering raising some capital really quickly and buying 3-4 of these machines to get set up this week.

http://www.alloscomp.com/bitcoin/calculator.php

With 1440 megahash p/s (roughly the rate of 2x6990) it would yield around $50 a day at current prices, minus $8 electricity (£3+other hw) would mean $42 a day. The setup is going to cost >£1k just for the cards, probably another £500 to get it going. So ~£25 a day would take 60 days to break even, if the BC to USD exchange rate of $20usd/bc remains relatively stable (no big drops).

Also the difficulty level is rising very fast. I've been told I've missed the boat pretty much. If I had one of these cards or a comparable one I'd be mining with it. My 5570 (I think!) can crunch 10% those speeds, = $5 daily, just not enough to be worth it. Requires serious GPU power.

I reccomend that you look into the 5 series as it is better for what you are on about and recalculate your numbers.

2x5870 @ £160 each = 1-2 coins per day, say 10 a week average. 10x $20=$200(£130) Cards payed for in roughly 2 weeks

A 4x system is 3 bit coins roughly. Water cool it and get 5+ per day, 35x$20=$700(£400) per week. For about a £2,000ish outlay....

Of cause its getting harder to mine and what will happen with bitcoin is unknown but theres risks to everything in life

You are insane looking at the inferior(for bit mining) 6 series

-=Vect0r=- · 16 Jun 2011 at 23:03

Hmm, never heard of this bitcoin mining malarkey.

I must admit I am a little sceptical on the matter.....

m3sSh3aD · 16 Jun 2011 at 23:17

-=Vect0r=- said:
Hmm, never heard of this bitcoin mining malarkey.

I must admit I am a little sceptical on the matter.....

I was until a good friend who knows his tech (beyond whats sensible) showed it and its potential. Im on it as we speak as i say with 2x5870's. 3 coins in less than 2 days so better than what i said above. Of cause, theres risk. Senite in america wants take it down cause of silk road etc etc, People have to believe in it like they do cash from THE BANK, which isnt worth the nylon its printed on!!!!! So why not bitcoin? it makes more sense than anything ibve heard or seen in the last 40 years!!!

And its open source, Its going no where.Ban it, it really does go to the dark side and it will be a criminal currency. Eitherway, Bit coin aint going nowhere quick

iviv · 17 Jun 2011 at 00:46

Personally I wouldn't be buying for BTC mining now. The value's leveled out at around £12/BTC, and its only going to get harder.
Though if you do have your heart set on it, as above go for the 5 series, more efficient, especially if you can overclock the core.

m3sSh3aD · 17 Jun 2011 at 00:54

iviv said:
Personally I wouldn't be buying for BTC mining now. The value's leveled out at around £12/BTC, and its only going to get harder.
Though if you do have your heart set on it, as above go for the 5 series, more efficient, especially if you can overclock the core.

Cant change voltage on this motherboard i have, Gigabyte p67A-D3-B3, But using shapphires trixx i got it stable at 930core/300 mem at 80C and 74C for the other card. Stock everything. 389mhash. 935 bit unstable but cant up the voltage as i say soo thats it for now for this comp

And as long as sites like "SR" are around, and theres plenty of them, thats just been the focal point for the news, Its only going up and up. Went 'SR' went down, BT's went to $8 from $20 haha. If you wanted know who uses bitcoins for what, there it is

Down with the banks

hehe

Buchanan0204 · 17 Jun 2011 at 00:55

I read briefly on Wikipedia what this BTC thing is. Can someone please explain to me how Graphics cards can earn you virtual money. According to Wikipedia no retailer accepts it as form of payment. So where do you spend this money?

It's all new to me, and I'm sure I'm not the only idiot who doesn't have a clue what all this is.

m3sSh3aD · 17 Jun 2011 at 01:04

Buchanan0204 said:
I read briefly on Wikipedia what this BTC thing is. Can someone please explain to me how Graphics cards can earn you virtual money. According to Wikipedia no retailer accepts it as form of payment. So where do you spend this money?

It's all new to me, and I'm sure I'm not the only idiot who doesn't have a clue what all this is.

Bit coins are basicallya way of getting rid o CENTRALIZATION that is in all currency today. THe banks/goverment have total controlof flow. Thats how they manipulate things. They can print it off at will though, ANd that devalues the currency (Although money as you know it isnt worth the nylon its printed on). So if you believe a bit coin can have the value as money, which is easy to do, you do it with the money in your pocket, its really worthless, its just that others AGREE that its worth what it says. With no centralisation there is no fees, noINFLATION dueto printing more off, It's limited to 21 million bitcoins. thats the key. No more will ever be produced AFTER that. Its very clever maths,. the program is open source and i dont believe anyones going be able make ikt disapear over night. The idea is out. Perople dont want banks/goverments/corperations and that sort controlling our lives and bitcoin is a possible first strike against fat cat bankers

weusebitcoins is the site which may help you out with the bit coin idea

and here is a list of sites and info that use bitcoin

https://en.bitcoin.it/wiki/Trade

The bitcoins need to be made and that takes processing powerto encode themall. Hense the software for 'mining'. Have a look from there and see what you think find