Bitcoin Forum

Hi,

I just recently exchanged my 2x7970 to 3x7950 (http://www.tigerdirect.com/applications/SearchTools/item-details.asp?EdpNo=7542562&CatId=7387). I wanted to start LTC mining, so I did for like 15 minutes and my rig started rebooting itself.... so it rebooted like 4 times(it would reboot once one of the cards temp would hit 80C (http://gyazo.com/a82b8754b29c96eb5cd430d56598d560), so i kept modifying the clocks until i can find one which doesnt hit 80C temp, but suddenly it turned off and never turned back on. I tested PSU on other machine - it did not work, so I wonder is the 1000W PSU not enough for 3x7950?

How can it kill a PSU? the PSU is 2 weeks old.
PSU LINK: http://microcenter.com/product/407836/ZU-1000B_1000W_Modular_ATX_Power_Supply

I'm going to return this tomorrow or exchange it to a stronger one.

Any ideas what happened here? did 3x7950 needed more power than the PSU could give them?

Thanks

Coolmax are not known for quality psus.

this

shouldve spent the extra $50-100 for a quality psu. I have one for sale if you are interested.
https://bitcointalk.org/index.php?topic=188942

I agree with the others on the PSU bit.  FWIW I have 3x 7950s with a healthy overclock on a 1000W XFX Ltd Black and there hasn't been a single hiccup.  That aside, I've got another 3 5850's and a 5970 drawing on a Corsair HX1050.  Again, not a hiccup.

Oh god Coolmax, you're lucky it hasn't taken the rest of the computer with it.

Toss that PSU in the garbage and buy a decent quality one. Check out JonnyGuru's website for recommendations.

1KW PSU (of a decent brand) should be fine for those cards

And these days always buy 80+ gold power supplies, at least then you know they used somewhat decent components to reach the certification specifications. 80+ bronze simply doesn't imply the quality it did a few years back since building efficient PSUs becomes cheaper and cheaper.

thanks - will drive to microcenter and return this one!

It's also not a bad idea to get a slightly more powerful PSU if you're running a mining rig in a case because the farther away from your maximum rating you are, the cooler the PSU is going to be.  One of my buddies was running one of his no-name brand PSU's at about 90% for his first week of mining and it was overheating the bottom card in his rig.  I tried touching it to see how hot it was getting and I'm pretty sure I could have cooked an egg on it.  To say the least, it failed before his replacement came.

As for names, you can't go wrong with Channel Well Technologies or Seasonic branded PSU's.  You will pay a little bit extra premium for their name brand but there are tons of PSU's out that that are relabeled from those two brand that will be cheaper and made from the same exact components.  Here is a list if you want to research who makes your rebranded PSU: http://www.tomshardware.com/reviews/power-supply-oem-manufacturer,2913-4.html (http://www.tomshardware.com/reviews/power-supply-oem-manufacturer,2913-4.html)  I usually just skip looking at prices and researching to opt for a Corsair HX series in the power range I need since CWT or Seasonic always make them.

True.  One bit of advice though.  I do sometimes buy lower quality PSU's for my miners but I factor that in.  I have bought many Rocketfish 900W supplies for great prices and then treat them like 700W.  Not one has died over two years. 

You can do the same for coolmax though i would treat a coolmax 1000W as a 700W as well.  If a quality 700W is cheaper, buy the quality unit but if a coolmax 1000W is cheaper then a Antec 700W and all you need is 700W, go for the coolmax.   I would stay away from true generics and brands that have no reputation at all. 

The brand name itself is usually irrelevant. Its the oem manufacturer that's important. Use a website like johnny guru to research oem on the power supply your going to buy and buy one recommended by them

ended up going with
http://microcenter.com/product/316092/Z_Gold_1000_Watt_ATX_Modular_Power_Supply

hopefully that will work!

just in case bought 2 year warranty(20$ extra) - covers everything

Should be fine, I ran a HD6970, a HD5870 and a HD7770 all off an OCZ 500W.  Changed it as the leads were starting to melt. :)  Got a used Zalman 1000W off eBay, job done. :)

Coolmax has a 3 year warranty on their PSU's...

Which came in handy today. A RM-1000B and a ZU-1000B let out their magic smoke today... they're replacing them with ZU-1200's tho...

Not that I'm going to Buy Coolmax again.