Power Req. 4 x 5970.

[Electricbees]

I am currently building a new rig which consists of:

890FXA-GD70
Sempron 140
Cheap-o DDR3 ram sticks
Linux on flash drive (No HDD)
And 4 5970's

No extra fans will draw power from the power supply

I know some members have tried the 4x5970 set up, so I am here to ask: What sort of power requirements would I need to complete this build?
I have not purchased a power supply yet, so I would like to know what I need.

I also plan to:

Underclock memory on the cards
Disable unnecessary bios settings
Anything else to get the non-GPU components down to a minimum stable power draw.

Suggestions? Personal experiences? I'll take anything you have...

[1714061929]

1714061929

[1714061929]

1714061929

[Mousepotato]

Just get an AX1200 and call it a day, especially if you're going to UC and UV.

[rjk]

Just get an AX1200 and call it a day, especially if you're going to UC and UV.

Hm. Four 300 watt cards on a 1200 watt PSU? Sounds legit.

[DeathAndTaxes]

Just get an AX1200 and call it a day, especially if you're going to UC and UV.

Hm. Four 300 watt cards on a 1200 watt PSU? Sounds legit.

5970 don't pull 300W while mining especially not with memclock down <300 (I run 150).

For OP:
3x 5970 (820/150) w/ sempron, usb linux, 2GB of ram = 870W AC (at the wall).  If we back out 10% for PSU inefficiency (likely is more like 13% but we will say 10% to be safe) it is ~800W DC load.  4x5970 in similar rig would likely be 1000W DC to 1050W DC.  Measured at the wall it will be 10% to 15% higher but remember PSU are rated in DC wattage not AC wattage.

1200 watts is likely sufficient bu you are going to be 80% loaded.
Alternative you could look into 1350W PSU (75% loaded) or a pair of PSU totalling 1600W (62% loaded).

A lot really depends on how efficient you want it.  1200W will work but it will be running a little heavy and likely 3% to 5% less efficient.  

1200W - simplest & cheapest, lower efficiency, make sure to buy a good brand 80-Plus Gold w/ good warranty.
1350W/1500W - significantly more expensive than 1200W PSU (that last 150W must be powered by pure gold pressed Bitcoins).
Dual PSU (1600W total) - more complicated, one extra component to fail.

[Proofer]

I am currently building a new rig which consists of:

890FXA-GD70
Sempron 140
Cheap-o DDR3 ram sticks
Linux on flash drive (No HDD)
And 4 5970's

No extra fans will draw power from the power supply
...

I have three 5970s on a 890FXA-GD70 with two 120mm fans sitting on top of the cards. I don't see how you can fit four and get adequate cooling, but I'm not really a hardware guy.

I would stick to sticks that are listed on MSI's compatibility sheet.  I had to replace the first ones I bought.

Sorry I can't help with your main question.  I am using the AX1200, but as mentioned with only three 5970s.

[DeathAndTaxes]

I have three 5970s on a 890FXA-GD70 with two 120mm fans sitting on top of the cards. I don't see how you can fit four and get adequate cooling, but I'm not really a hardware guy.

That is the setup I use.  To use 4x5970 will REQUIRE extenders.  Period.

[Electricbees]

*Extenders will be involved.*
There is no way I would be trying to cram all four onto that board with such a tight clearance. The airflow would be next to none...

@Proofer

One of my current rigs uses an MSI board with one stick of incompatible ram, and is incapable of anything beyond mining and browsing the web without getting BSOD. I didn't wasn't aware of compatibility issues with the boards until now... Thank you for bringing this to my attention.

@D&T

You've stated an estimated draw for my theoretical rig somewhere in the threshold of 1000-1100W.
So, to increase actual efficiency of my rig as a whole, I should get a PSU which powers well beyond that?
Efficiency increases as total load percentage decreases, correct?

According to this, a 1500w Gold-rated PSU would supply the same DC current to my rig as a 1200W PSU, but would draw less Wattage AC at the wall?
Important should this rig find a place on my only free power source, consisting of one 20amp circuit.

Lastly, an AX1200 would definitely suffice for this set up?

[DeathAndTaxes]

Yeah generally peak efficiency is around 50% to 60% of PSU rating. 

That being said for high end 80-Plus Gold PSU the curve tends to be very flat.  So while 80% loaded may be less efficient it may only be 3% or so less.

Some PSU provide the efficiency curve.  The bad news is most don't.

According to this, a 1500w Gold-rated PSU would supply the same DC current to my rig as a 1200W PSU, but would draw less Wattage AC at the wall?

Yes a larger PSU isn't going to use more power it likely will use less power because it is operating at a higher efficiency for a given load. 

Important should this rig find a place on my only free power source, consisting of one 20amp circuit.

A dedicated circuit is always best but you can use other circuits depending on what is on it.
A 120V, 15A circuit shouldn't be loaded more than 80% for continual loads.  That is ~1400W.  If you have 1100W DC @ 88% inefficiency you are looking at 1250W AC.  That is going to use up most of a 15A circuit. 

Lastly, an AX1200 would definitely suffice for this set up?

AX1200 should be fine if it is a DEDICATED mining rig going w/ the concepts above (sempron, usb linux, underclocked memory, etc).  A larger or dual PSU would increase efficiency slightly.

[jjiimm_64]

I might as well chime in, I just built another one like this last night.

when I originally built my first 4x5970 rig, the psu was a silverstone 1200. it would run stable at 775/420, but NOT at 800/420. I then went with 2 seasonic  1 750 and 1 650 for each of the next 4.

My latest build is 4x5970 with a seasonic 1250.  it has been at 820/300 for about 12 hours.

Code:

cgminer version 2.1.2 - Started: [1326773438]    Rig: miner16
(5s):?  (avg): 2963.21 Mh/s  |    Q:11222   A:22530   R:167   HW:0   E:?%   U:39.36/m
TQ:?   ST:17   SS:?   DW:730   NB:57   LW:51007   GF:3   RF:62
Connected to http://192.168.1.100:8332 without LP as user ?
GPU 0:	54.5C	3084RPM 	50% | 	374.9/374.5Mh/s | 	820Mhz 	1.05V 	A:2841	R:20	HW:0	U:4.96/m 	I: 7
GPU 1:	57.0C	  	             | 	368.0/372.2Mh/s | 	820Mhz 	1.05V 	A:2790	R:25	HW:0	U:4.87/m 	I: 7
GPU 2:	53.5C	3101RPM 	50% | 	373.4/372.1Mh/s | 	820Mhz 	1.05V 	A:2777	R:22	HW:0	U:4.85/m 	I: 7
GPU 3:	54.0C	  	             | 	372.9/372.2Mh/s | 	820Mhz 	1.05V 	A:2759	R:19	HW:0	U:4.82/m 	I: 7
GPU 4:	60.0C	2906RPM 	50% | 	373.5/355.8Mh/s | 	820Mhz 	1.05V 	A:2758	R:25	HW:0	U:4.82/m 	I: 7
GPU 5:	61.5C	  	             | 	372.9/372.3Mh/s | 	820Mhz 	1.05V 	A:2866	R:19	HW:0	U:5.01/m 	I: 7
GPU 6:	60.0C	3081RPM 	50% | 	372.7/372.0Mh/s | 	820Mhz 	1.05V 	A:2880	R:15	HW:0	U:5.03/m 	I: 7
GPU 7:	61.0C	  	             | 	376.9/372.0Mh/s | 	820Mhz 	1.05V 	A:2859	R:22	HW:0	U:4.99/m 	I: 7

[Chefnet]

just use 800/150 with intensity 9 (750mh/s): my rig needs 550W (with 2x5970 = 2,72 MH / W), AMD X2 240e, 2 GB Ram, 160 GB Hdd, GA-770... AM 3 Board. if you count the system (cpu, board, hdd, 1 extra fan with 50W) one 5970 pulls about 250W so normally the AX1200 should do well (but like discussed a bigger psu or 2 with adapter will be a little bit more efficient).

[Chefnet]

or this one

http://www.ocztechnology.com/ocz-zx-series-1250w-power-supply.html
http://www.tweakpc.de/hardware/tests/netzteile/ocz_zx_1250/i/imgE.png

[DeathAndTaxes]

or this one

http://www.ocztechnology.com/ocz-zx-series-1250w-power-supply.html
http://www.tweakpc.de/hardware/tests/netzteile/ocz_zx_1250/i/imgE.png

Yeah that is a nice PSU.  It has everything I look for

1) A single MASSIVE 12V rail  (not that multiple 12V can't work but you need to do a little more homework)
2) 1248W of the 1250W are available as 12V.  For mining 12V is really all we care about.  The 3.3V and 5V are used only in token amounts.   The -12V isn't used by any modern system and can likely be dropped from the spec.
3) Up to 90% efficiency and very flat across broad range of likely usage loads.



Another nice unit is the 1350W MaxRevo by Enermax.  It is pretty expensive for a dedicated miner but I use it in by 4x5970 watercooled workstation that also has 16GB of ram, high end -7 CPU, RAID, etc.  Other than the price it is the single best PSU I have every used. 


A side note.  I agree with google that the ATX spec likely could and should be simplified to simplified to be 12V only.  Technically 24V would be better but that would make it incompatible w/ all current ATX components.  Having everything run at 12V would mean cheaper, higher efficiency PSU.  95%+ efficiency is likely possible and economical.

[jjiimm_64]

I tried unsuccessfully to find the efficiency curve chart....  seasonic

http://www.newegg.com/Product/Product.aspx?Item=N82E16817151109

[DeathAndTaxes]

I tried unsuccessfully to find the efficiency curve chart....  seasonic

http://www.newegg.com/Product/Product.aspx?Item=N82E16817151109

I have seen it claimed that the XFX Pro 1250W is simply an OEM rebrand of the Seasonic 1250

http://www.hardwareheaven.com/reviews/1325/pg5/xfx-pro-1250w-black-edition-full-modular-power-supply-review-synthetic-testing.html

If it is the same unit then it looks to be 91.5% efficient @ 50% load, 91% efficient at 75% load, and 88.5% efficient at 100% load.

[MiningBuddy]

I might as well chime in, I just built another one like this last night.

when I originally built my first 4x5970 rig, the psu was a silverstone 1200. it would run stable at 775/420, but NOT at 800/420. I then went with 2 seasonic  1 750 and 1 650 for each of the next 4.

My latest build is 4x5970 with a seasonic 1250.  it has been at 820/300 for about 12 hours.

Code:

cgminer version 2.1.2 - Started: [1326773438]    Rig: miner16
(5s):?  (avg): 2963.21 Mh/s  |    Q:11222   A:22530   R:167   HW:0   E:?%   U:39.36/m
TQ:?   ST:17   SS:?   DW:730   NB:57   LW:51007   GF:3   RF:62
Connected to http://192.168.1.100:8332 without LP as user ?
GPU 0:	54.5C	3084RPM 	50% | 	374.9/374.5Mh/s | 	820Mhz 	1.05V 	A:2841	R:20	HW:0	U:4.96/m 	I: 7
GPU 1:	57.0C	  	             | 	368.0/372.2Mh/s | 	820Mhz 	1.05V 	A:2790	R:25	HW:0	U:4.87/m 	I: 7
GPU 2:	53.5C	3101RPM 	50% | 	373.4/372.1Mh/s | 	820Mhz 	1.05V 	A:2777	R:22	HW:0	U:4.85/m 	I: 7
GPU 3:	54.0C	  	             | 	372.9/372.2Mh/s | 	820Mhz 	1.05V 	A:2759	R:19	HW:0	U:4.82/m 	I: 7
GPU 4:	60.0C	2906RPM 	50% | 	373.5/355.8Mh/s | 	820Mhz 	1.05V 	A:2758	R:25	HW:0	U:4.82/m 	I: 7
GPU 5:	61.5C	  	             | 	372.9/372.3Mh/s | 	820Mhz 	1.05V 	A:2866	R:19	HW:0	U:5.01/m 	I: 7
GPU 6:	60.0C	3081RPM 	50% | 	372.7/372.0Mh/s | 	820Mhz 	1.05V 	A:2880	R:15	HW:0	U:5.03/m 	I: 7
GPU 7:	61.0C	  	             | 	376.9/372.0Mh/s | 	820Mhz 	1.05V 	A:2859	R:22	HW:0	U:4.99/m 	I: 7

I've been told that 5970s and 6990s draw the full 75w from your pcie slot, how, with 4 on 1 single board do you not melt your 24pin atx plug on your motherboard? Apparently that plug is only rated for 150w total.
I also read the same here: http://blog.zorinaq.com/?e=44

I would like to know as I have some 5970s coming in soon and want to put 3 on a single board without having to mess around making powered risers.

[DeathAndTaxes]

I've been told that 5970s and 6990s draw the full 75w from your pcie slot, how, with 4 on 1 single board do you not melt your 24pin atx plug on your motherboard? Apparently that plug is only rated for 150w total.
I also read the same here: http://blog.zorinaq.com/?e=44

They don't and the link you provided states the same thing.

Each HD 5970 draws 3.7A@12V from the slot alone, excluding the 6-pin and 8-pin power connectors.

3.7 * 12 = 44W  That is running at full memclock.  When mining @ 820/150 I measured ~35W using a clampmeter.

More info from the author of whitepixel

http://blog.zorinaq.com/?e=42

Designing for 1000+ Watt

Power was of course the other tricky part. Four HD 5970 cross the 1000 Watt mark. I chose to split the load on two (relatively) low-powered, but less expensive power supplies. In order to know how to best spread the load I first had to measure the current drawn by a card under my workload from its three 12 Volt power sources: PCIe connector, 6-pin, and 8-pin power connectors. I used a clamp meter for this purpose. This is where another advantage of the flexible PCIe extenders becomes apparent: the 12V wires can be physically isolated from the others on the ribbon cable to clamp the meter around them. In my experiments with whitepixel, the current drawn by an HD 5970 is (maximum allowed by PCIe spec in parentheses):

PCIe connector (idle/load): 1.1 / 3.7 Amp (PCIe max: 6.25)
6-pin connector (idle/load): 0.9 / 6.7 Amp (PCIe max: 6.25, the card is slightly over spec)
8-pin connector (idle/load): 2.2 / 11.4 Amp (PCIe max: 12.5)
Total (idle/load): 4.2 / 21.8 Amp (PCIe max: 25.0)

[MiningBuddy]

I've been told that 5970s and 6990s draw the full 75w from your pcie slot, how, with 4 on 1 single board do you not melt your 24pin atx plug on your motherboard? Apparently that plug is only rated for 150w total.
I also read the same here: http://blog.zorinaq.com/?e=44

They don't and the link you provided states the same thing.

Each HD 5970 draws 3.7A@12V from the slot alone, excluding the 6-pin and 8-pin power connectors.

3.7 * 12 = 44W

When mining (which has reduced memclock) I measured ~35W using a clampmeter.

That's good to know, thank you for the correction.

[ArtForz]

I tried unsuccessfully to find the efficiency curve chart....  seasonic

http://www.newegg.com/Product/Product.aspx?Item=N82E16817151109

I have seen it claimed that the XFX Pro 1250W is simply an OEM rebrand of the Seasonic 1250

http://www.hardwareheaven.com/reviews/1325/pg5/xfx-pro-1250w-black-edition-full-modular-power-supply-review-synthetic-testing.html

If it is the same unit then it looks to be 91.5% efficient @ 50% load, 91% efficient at 75% load, and 88.5% efficient at 100% load.

It is. And here's the X1250 (aka SS-1250XM) 80+ test report: http://www.plugloadsolutions.com/psu_reports/SEA%20SONIC_SS-1250XM_ECOS%202811_1250W_Report.pdf

[DeathAndTaxes]

It is. And here's the X1250 (aka SS-1250XM) 80+ test report: http://www.plugloadsolutions.com/psu_reports/SEA%20SONIC_SS-1250XM_ECOS%202811_1250W_Report.pdf

PSU have gotten so much better.  80Plus may be an imperfect standard but the curves have gotten a lot flatter recently.

I mean 50% load 91.4%, 100% load 88.7%. I love it.

Thanks for the link  Nice to know that my Enermax MaxRevo 1.35KW is rated @ 88.5% even at 1350W.  I wish they also tested them @ 240V.

[Mousepotato]

Hm. Four 300 watt cards on a 1200 watt PSU? Sounds legit.

I run a single 5970 and my entire rig pulls 235W while mining, 138W while idle.  So the card itself is pulling around 97W.  Add another 3 of them and I might break 700W for the whole system.

I run mine undervolted to 950mV, 605/166MHz, 550 MH/s.  In that config it's more than 1 MH/watt more efficient than the most efficient config on a 7970.