Bitcoin Forum

   I have been reading all I can find on wattage ratings for gpu's, there is a wide variety of opinions. Ratings for 3  7950's range from 535 to over 1000 watts. AMD says 7950 is

limited at 200 watts which I would say is probably about right. what I'm getting at 2 different power supply calculators rated 3  7950 system at 1015 watts. seems kind of high

to me. I have 2  7950's on a 750 watt psu no problem. Does anyone have 3  7950's on a 1000 watt psu? I have a Rosewill RBR1000 Bronze. I hate frying psu's. Ran 3 5830's on

a 750 watt HEC for 6 months, changed it to 2  6870's and a 5830...Lasted almost 5 minutes. 1000 watt psu's are to expensive to waste.

 Sorry for posting this, I just read on this forum someone with 3  7950's shows 1080 with a kil-a-watt meter, maybe I'll through my 7870 in with them and run 2 smaller psu's.

I always like a "safety buffer" for several reasons. I have used 2 PSU's many times in the recent past but 1 large PSU is better for me.

200 watts per card plus 200 for mobo cpu, etc = 800 watts + 15% breathing room = 920watts.  I'd get a 950watt Platinum, Silver, or Gold for that rig.  

150 watts higher if you plan to do excessive overvolting.

Higher if you want more cards in the future.  

He could have been doing extreme overclocking or using a very inefficient cheap PSU or both.  It also depends on his CPU and socket type. lga1366 & lga2011 are power hungry

As an example; I have 4 of my 7970s,mobo,ivy bridge cpu,etc hooked up to a silverstone 1200watts and it sucks 1000+/- from the wall.

I do undervolt 10-12% though

I run 3x 7950s per rig and this is the only power supply I use.
http://www.newegg.com/Product/Product.aspx?Item=N82E16817207021&IsVirtualParent=1

I'm fairly certain I could do 4 cards per board, but I left that open for upgrade later. :D

One system has a low power APU and the other has a low power AMD x4 either pulls like 65w.

I've got 3x 7950's on a XFX Pro 1000W Plat.  No problems.   Not sure about usage, I should check that.

I am running 3 7950 on a antec hcp 1000
there was a 7850 in the system before I pull it out.
I don't oc the card too much, only about 40 above stock core and keep stock memory clock @ 1.013v hashing @ 550-560 each

so basically I thing I am not pushing the PSU at all, and I am thing to swap in a hx850 instead....but not sure if that's safe

I run 800w with undervolt and slight overclock, full power and overclock you will hit 1200w, i have a gold 1300w psu

I am running 3x Gigabyte 7950 on a ThermalTake 850 Gold.

No powered risers.

Rosewill LIGHTNING-1300 1300W
http://www.newegg.com/Product/Product.aspx?Item=N82E16817182063

Running 4 7950's with monitor and box fax to around 810KW.

Same

I have 5 7950 on 1200 W PSU (Enermax MaxRevo 1200W)

I am building a 3x 7950 rig without risers, do you mind to provide some info about your motherboard?

Sure, don't laugh, but this has worked wonders and I have purchased another cpu/mb to get another rig made.

Gigabyte GA-H61MA-D3V with Celeron G1610 processor.  Used the unpowered PCIe x16 to x1 at the $3AU pricing with free shipping from ebay (bought 18 as I have plans that I hope my wife ignores  ;D ).

hahah!  Good luck!  My wife has officially shut down my mining rig expansion :(

.... for now!

Life lesson: If you plan to GPU mining at home, think twice. You will get a lot of heat and an angry wife  ;D

990FX MB, FX6100 AMD(stock clocks), 16GB RAM, SATA HD, 4-7950 (Stock clocks, slightly undervolted), 4 - 120mm fans. 4 CPU cores loaded on Boinc, pulling 1140 watts at the wall. 1089 watts with CPUs idle. OCZ 1250 Gold PSU.

      How do you measure consumption (which instrument - the software)?

Kill-A-Watt meter.