1Kw PSU apparently not enough juice for 2x7970's Ghz Editions...

[Joori]

Recently built a mining rig and slapped in 2x7970's Ghz editions with the 1100/6000 clocks backed by what I thought would be ample power with a bargain buy Powercooler 1050w PSU. I almost shit myself when I fired up cgminer and seeing the top card's temp rocket within seconds to 99C before a loud pop and massive bright spark spewed it's way out of the exhaust of the PSU. The system switched off and isn't turning back on anymore. I'm worried that I might have fried something else aside from the PSU namely a card or two.... I tried the paper clip test on the PSU and yep she's dead as a door nail, wont turn on. Problem is my current desktop rig's PSU only has 2x6pin power plugs so I can't test the cards on it to see if they are still ok as they are 1x6pin and 1x8pin plugs each.

Definitely need another PSU that's for sure but what I failed to read was the correct wattage specification for these cards.. I stupidly led myself to believe I'd be looking at between 250-300w per card when in actual fact it's 600w per card! I really hope they are ok, they're only 2 days old, heck I could have even blown the mobo for all I know at this point - Woe Is Me!

[1714021020]

1714021020

[ontoguzzi]

I think you had enough power, just PSU was bad...I had 2X7970s on 800/850W PSU running without any problems. Hope your vidcards are OK.

[Sophokles]

Definitely need another PSU that's for sure but what I failed to read was the correct wattage specification for these cards.. I stupidly led myself to believe I'd be looking at between 250-300w per card when in actual fact it's 600w per card!

Correct, you'll need another PSU. Sorry to hear about your experience. Better go for a brand name next time. But 1000W is more than enough for 2*7970. Powerdraw is 250W per card at stock settings on my rig, what gave you the idea that it's 600W per card?

[-ck]

Not all PSUs are created equal. There is WILD variation in claims of what power they can produce and they don't measure them at meaningful operating temperatures, and they have multiple rails etc... I have an OCZ gold 1250W PSU and ran 4x7970s at average clocks of 1175 and it drew ~1100 watts at the wall and never skipped a beat.

[Joori]

Card #1 and Card #2 are the two I bought. Specifications list 600w for power requirement. I thought this was a mistake so went looking at the gigabyte website and it too lists the power requirement at 600w... Mind you AMD website states slightly different for the Ghz Editions listed below;

Code:

500W (or greater) power supply with one 150W 8-pin and one 75W 6-pin PCI Express power connector recommended8
850W power supply (or greater) with two 150W 8-pin and two 75W 6-pin PCI Express power connectors recommended for AMD CrossFire™ technology.

They did have another page which I can't seem to find now that stated 300w or so, which was kind of in line with the mining hardware comparison wiki chart. Tho I'm inclined to believe they were listing cards with lower clocks? Either way, I'm hoping I've just lost $89 in equipment rather than over 1K....

TBH, I almost always go for brand names, especially with PSU's. I really don't know what the hell I was thinking buying something that seemed suspect. One thing's for sure, I'm going to have a hard time explaining my stupidity to the sales team at the store when I go there tomorrow 

[kevinm]

Con,
Would that be OK for scrypt mining also?
I have 4 Sapphire 7970 OC with Boost and the only PSU available at the mo is a Seasonic X-1250W 80 Gold.
Dont want to knacker anything up, I would rather run 3 cards and be safe than risk it with 4 on LTC.

cheers,
Kev

[Lethos]

Just to clear things up.

The Graphics card uses around 250 Watts.
There are other things in the system, that also use power, like the processor (CPU), ram, hard drives, motherboard etc.

So when they say power requirement, it's talking as a total of your system, not what is needed just for the graphics card.
It was technically suitable to get a 1000W PSU, the problem is that since it was an PSU from an unreliable source, it couldn't really cope with doing anywhere close to 1000W (lies on specifications). That is why you always make sure you get a quality PSU.

kevinm - Seasonic is a good PSU, so it should be fine to cope with 4 of those beasts, as long as you are not going over the top on the other components used with it. You bigger problem will be cooling them all, they'll generate a lot of heat.

[ISAWHIM]

What are your AMPS for the 12v...

I see many crappy PSU's that "max" at 1000w, but 30% of that is on the 3.3v and 5v rails... Totaly useless power.

EG, your 12v rails might only be 18-20a each... 2 of them... Thus, you only have 240w max, per rail... If you put one rail on BOTH cards, and the other was on your hard-drive... you tried to draw about 500W through one of the 240w rails, and fried the "rail-regulator" as it attempted to divert power from the other rail.

Always get mono-rails... It is useless getting split-rails, unless you exactly match the rails to the loads, which is impossible to actually do.

The cards pull 250w each, CONSTANT, and up to 300w peak, at 100% load. (Clock and voltage dependent.) That is at a constant 12v source... at 11.5v, it draws up to 350w peak.

I would be willing to bet your rails fell below 11v, due to load, and the amps fried it up good.

Find a good 48amp 12v rail for two cards... and 68amp 12v rail for three cards. Respectively (576w and 816w maxes, on JUST the 12v supply... thus a 650w and 1000w PSU.) Just to be, "Safe".

Or underclock, and use a kill-o-watt meter to "see" your actual at-wall-wattage, so you can use a cheaper PSU and run it under 200w each card, with a 500w PSU for two, and a 750w PSU for three cards.

NOTE: If you get a cheap PSU to operate the fans separately at 100%, you can remove them from the power-draw of your computer PSU, and use a real cheap PSU to power the cards. Because about 25w is just for the fans, on each card... up to 35w on the three-fan models. (2.08a to 2.91a, when fans run 100% through the controller and regulator, which lowers the boards available voltage also.) Save more money by using 120vAC fans, not 12vDC fans, which consume more power to do a lot less... EG, a bathroom exhaust blower fan.

You could use 2x 500w PSU's to power the whole system. $25 for each PSU... as opposed to 1x overpriced $250 1500w PSU.

[Joori]

Just to clear things up.

The Graphics card uses around 250 Watts.
There are other things in the system, that also use power, like the processor (CPU), ram, hard drives, motherboard etc.

I figured it was total of the card itself but ofc I could be wrong.. None the less, it's hard to imagine I'd reach even close to 1Kw with the current mining rig.

AMD AM3 FX-8350 Black Edition (Eight -Core 4.0 GHz)
Gigabyte 990FXA-UD3
16GB G.Skill 1600Mhz
2*7970's
1*SATA 160GB
1*Pioneer DVD Burner
1*Wireless Netgear WG311 Card
Sharkoon T9 Value Case with 3*120mm LED Fans that came with it.
Powercooler CoolerPower 1050w Extreme Power (Dodgy) PSU

I'm leaning towards it not being able to draw nearly close to what it's advertised as being able to output... My desktop rig has been rock solid for a good year now and it's got a considerably less rated PSU tho somewhat decent and running enough devices/apps to keep a small nerd farm happy for a while...

Core i7 950
Gigabyte X58A-UD3R
12GB Corsair XMS 2133Mhz
1*Nvidia GTX570
6*SATA Drives 500GB-2TB (Non-Raid)
1*USB3.0 2TB External
1*USB3.0 micro usb cable charging my S3 as we speak
1*Pioneer DVD Burner
Logitec 1080p USB webcam
Canon MP970 Printer
Audio Jacks in use
Sexy Coolermaster Inferno USB mouse flashing it's sexy LEDS at me
Bog standard USB K/B
3*120mm LED case fans
Lian-Li Extreme Power 650w PSU

It's been mining for 3 months straight and is doing so as I type this reply... I game with this machine while mining on occasion too with little effort. I can quite comfortably max out all settings while gaming and mine at the same time. Most of the time I forget I'm mining but am reminded as soon as I focus on the insanely loud fans on the GTX570 lol

Interestingly, the AMD's stock HSF is stupidly louder... I watched it rev upto 8K RPM while i was playing with fan speeds... the two 7970's were drowned out by this little jet engine and they both had their fans full blast

What are your AMPS for the 12v...

I couldn't say what the rails were reporting when I began mining on the AMD rig, but while idle installing windows updates, MSI afterburner, Catalyst and other shit before I tried mining, all the rails and voltage readings were on par. That is to say the 12v rail was steady.. Tho I just ripped the PSU out to take an image of the specs. It was a pain in the arse to install and hide the cables, even more of a pain in the arse to remove!!  My apologies it's a CoolerPower not PowerCooler! Still dodgy to f... heh.

Image of PSU Infos

[-ck]

Con,
Would that be OK for scrypt mining also?
I have 4 Sapphire 7970 OC with Boost and the only PSU available at the mo is a Seasonic X-1250W 80 Gold.
Dont want to knacker anything up, I would rather run 3 cards and be safe than risk it with 4 on LTC.

Yes it was ok for scrypt as well, though the power went up by another 80W. Single rail is vital. I was worried since they were all mounted directly on the motherboard instead of powered risers that the motherboard would fry, but I never really mined scrypt for very long except for testing (since I only believe in bitcoin). The PSU was fine though. Seasonic PSUs are excellent.

[HellDiverUK]

I figured it was total of the card itself but ofc I could be wrong.. None the less, it's hard to imagine I'd reach even close to 1Kw with the current mining rig.

AMD AM3 FX-8350 Black Edition (Eight -Core 4.0 GHz)
Gigabyte 990FXA-UD3
16GB G.Skill 1600Mhz
2*7970's
1*SATA 160GB
1*Pioneer DVD Burner
1*Wireless Netgear WG311 Card
Sharkoon T9 Value Case with 3*120mm LED Fans that came with it.
Powercooler CoolerPower 1050w Extreme Power (Dodgy) PSU

I run similar - FX8320@4.4GHz, 16GB RAM, 256GB SSD, 6x120mm fans (Scythe Gentle Typhoon), HD7950, HD6970, HD5870, HD7770 all off a 1000W Zalman PSU that I got used off eBay for basically nothing.  The Zalman's fan barely spins, and it runs cool.  It's drawing 800W from the mains doing BTC, about 900W doing LTC.

I think your PSU was just a bit crap to blow up like that.

[kevinm]

Lots of really good info on this thread for a relative noob like myself,
Thanks very much fellas.

Kev

[Joori]

Lots of really good info on this thread for a relative noob like myself,
Thanks very much fellas.

Kev

I agree totally, just don't blow your shit up like I did on account of not fully checking what you're buying!

I run similar - FX8320@4.4GHz, 16GB RAM, 256GB SSD, 6x120mm fans (Scythe Gentle Typhoon), HD7950, HD6970, HD5870, HD7770 all off a 1000W Zalman PSU that I got used off eBay for basically nothing.  The Zalman's fan barely spins, and it runs cool.  It's drawing 800W from the mains doing BTC, about 900W doing LTC.

I think your PSU was just a bit crap to blow up like that.

Right, well at least I have some reassurance that what I thought I was buying should have been ample for the rig. I just really, really, REALLY hope the PSU was all that went... I'll take my cards with me when going to the store and see if they can chuck them in a system to test for me while I hunt down a new PSU. If they are toast, then I can deal with that problem while I'm there rather than finding out later on that they're foobar'd.

[DBG]

Without actually testing the hardware itself I couldn't tell you, but this really sounds like a capacitor blowing (which if the rest of the components did their job correctly, saved any hardware aside from the PSU from getting fried).  Just to throw my hat in the ring, I would personally recommend checking out Antec's lines of PSUs.  I have a PSU from their "TruePower" line in my main desktop, but that's just because it runs quiet (I designed my whole system to run silent under full load without any acoustic padding or water cooling, so this was a must).

As far as projects though, I am using one of their higher-end models.  It might be overkill (for both my purposes and yours) but I would suggest at least checking it out - HCP-1000 Platinum.  This particular PSU actually has 4 dedicated 12v rails in case you ever want to get crazy with more cards.  A great thing too is it really is an investment product.  All of Antec's PSUs come with a modular cable design, but this unit and a few others are actually future proof when it comes to the needs of motherboards and other hardware that has yet to be released.  I've really thrown a lot at mine (more than I should to be honest, but I figure with a 7-year replacement warranty, why not? =p).  Also since you'll likely be running your system 24/7, it's nice that it's 80 PLUS Platinum certified (that basically means that there is very little power that goes to waste due to heat or power leaks).  Again, we're looking at an extreme version; but I would never buy a PSU that wasn't at least 80 PLUS Bronze certified.  If you decide you need less power they have lots of different models with various features (what everyone recommended above is golden info).

For a more cost effective model that should do by you just as well, I'd go with EVGA's SuperNOVA 1000 G2.  We actually use these PSUs inside the workstations in the rendering lab (dual nVidia Quadro 6000s setup in SLI; it's actually pretty cool because you can make the system think you just have one powerful GPU - bleh forgot, this is BCT, no one cares about nVidia  ); anyway they are rock-solid, solid Japanese capacitors just like Antec uses, 10 year replacement warranty and is 80 PLUS Gold rated.  Hope that helps some!

[dimke_yu]

I have 4 x 7950 and when they mine bitcoin consumption from wall is around 850-900W depending on clocks, but when I tried scrypt on semi aggresive settings it pulled over 1000W from wall. So be careful when mining scrypt as it drains more power.

[shiv]

I'm running three 7950's on a 750w PSU.
These cards (or the 70's) don't use that much power at all.
Your PSU was bad.

[cp1]

Recently built a mining rig and slapped in 2x7970's Ghz editions with the 1100/6000 clocks backed by what I thought would be ample power with a bargain buy Powercooler 1050w PSU. I almost shit myself when I fired up cgminer and seeing the top card's temp rocket within seconds to 99C before a loud pop and massive bright spark spewed it's way out of the exhaust of the PSU.

It sounds like that card's the problem.  I don't think it should hit 99C within seconds.  I doubt the PS would cause that.

[GenTarkin]

dude, NEVER FUCKING BUY a bargain priced PSU thats of no brand, especially a cheapass highwattage PSU..
Their a flatout lie, and yes they can get away w/ it for some reason legally...no fucking idea why, it should be fucking outlawed to lie that much to a customer.
But yes, manufactures often can fake the logos for many of the certifications they have to pass to be 'safe'
Such as UL etc...
There are cheap high watt PSUs all over the place that make me fucking pissed off. They can handle most like maybe 200watts when they are labeled 600+ watts.
On top of that .. the shit PSUs feed horrible quality DC to your PC components...causing all sorts of stress on their VRMs ... its a sad situation.

[MysteryX]

I don't buy a PSU unless Jonny Guru has tested it, if you buy a garbage one it can damage all your hardware.
I usually stick to Corsair / Seasonic / Lepa / Enermax models.

[Littleshop]

A PSU also should not be light.  If you pick up a 900W power supply and it feels light it is probably crap.  Pushing out high power takes serious components that have weight to em.  I have found some off brand supplies that have done well, like Rocketfish.  I get Rocketfish 900W supplies and treat them like 700W units.  Out of 6, not have died over two years.