Topic: PSU not powerful enough or am I just stupid? (Read 281 times)

you need to set aside 20% headroom plus 150w for mobo/cpu/ram/etc.  then one should be lowering the power setting on their cards.  60-80% is typical.

Just attaching some pictures to your post , its from the same article you mentioned

@nc50lc: amazing that you have the photos of both my power supply labels! I am impressed

Thanks for all your explanations. Makes sense.

What hit me was the notion of "spikes". Even if my watt meter reads 200W / card, there are spikes and these are what causes the shutdown.

Thanks again.

Did you even read my post, the stated power was for the 12v rail. 80% is the safest load because the Processor, SSD/HDD, Fans and others are also using that rail.

It doesn't even requires a thorough (long, agree to this and disagree to that) explanation to tell the OP author: Get a Bigger Power Supply.
38A / 456W in the 12v Rail.

62A / 744W in the 12v Rail.

Yes absolutely agree with the server PSUs used. It's durability designed for running 24/7 but so far as I know the server PSUs prices more expensive. It may that make some miners choose to use non-server PSU. And the solution is to give our RIG more a spare power.

Like the above says... consumer grade hardware isn't designed for 24/7 usage - which is one of the reasons I chose a server PSU (with a mod card that takes it's 12V rail and delivers it to up to 12 PCIe 6/8 pin cable/plugs). The mod card has an LED display that shows output voltage and if I have only 1 rig running it's at 12.6, but when I run both it drops to 12.5 or even 12.4 if I'm mining a power intensive algorithm like neoscrypt. That is a 1200W PSU running at about 800-900W. I wouldn't add any more load to it. It could take at least another gtx1060 but I don't want it delivering any more than it is.

If you look at the graphs that PSU manufacturers publish for the "gold" rated devices, they seem to run most efficiently when they are at around 60-70% load. "Platinum" rated PSUs are most efficient even higher than that, but I don't think the extra $ is really worth it. I'm lucky to live in a country where we have 240V AC power so everything is a bit more efficient, but unfortunately electricity is VERY expensive here (Australia).

why some member suggests using Power PSUs a bit the rest power after calculating the TDP GPUs or their never calculated how many power consumption need. I often saw some member suggest the PSUs has the rest power 100-200 W. and their say enough.

come on, the best  power PSUs has the rest 300-400 W because power PSU can be influenced by the downhill rise of your home power voltage. if the rest that, keep the other parts not short of power and longer service life.

You are somehow not accurately measuring true power power consumption. The Nano can pull up to 250 watts each under full load. Anandtech measured 327 watts for full system load playing Crysis 3. TDP is not the same as peak, especially when mining. Your Celeron, MB, and HDD can pull 75 watts on mild load easily. That's 575 watts peak for 2 cards and 825 watts with 3. You are underpowered.

I'm quoting you just to register that what you are saying  is nonsense.
The PSU, a good one, will always be capable of deliver exactly as advertise.

Said that, if you check what is wrote on the psu, you'll see that not all of its power is dedicated to the 12v rails.
So OF COURSE you can't use all of its power to feed GPU simply because part of it it's dedicated to the 5v and 3.3v rails.
And that is the OP  problem.

Another thing is those PSUS were not made to work 24/7.
So a headroom is always a good idea.

20% as the user above said is just the minimum and it us usually used to get from the psu the best performance  (eficiency ).

But remember,  it's not made to work 24/7....

Pick some 850w  and you'll very fine.
I'm feeding my Vegas with 2...

In name of JESUS, read the spec of what you are buying!

I always give myself at least 20% headroom, so If I expect a rig to use 700W I buy and 850W or 1000W PSU. Or use dual PSUs,

Like for example I have one rig which is 4 x gtx1070 plus 1 x gtx1080 which uses 1 850W PSU for the motherboard, ssd, fans, all 5 risers, etc plus the 1st 2 GPUs. That 850W PSU is on a watt meter and it's generally using 500-700W, then the other 3 GPUs are attached to a modded 1200W server PSU on which the only outputs are the PCIe 6/8 pin 12V plugs.

I am also running another rig in a similar setup, but it is 4 gtx1060s plus 1 x gtx1080 so the primary PSU is a 750W PSU. Again the primary PSU powers everything except 3 of the 5 GPUs - and those 3 are also receiving PCIe power from the modded server PSU.

So.. I have 3 PSUs but one of them - rated at 1200W which has only PCIe 12v outputs - is powering 2 x 1060s 2 x 1070s and 2 x 1080, across 2 different rigs.

Everything has a common ground (I have connected all the PSU cases with a thick jumper wire).

This is all just an example to show that I have A LOT of extra power capacity. In your 1st example where you say:


I would say that the 460W PSU is WAY too small. A Nano may be rated at needing 200W continuous power, but it's likely to have spikes where it needs much more than that for a fraction of a second, probably especially when a miner starts up. If you get 2 of them both needing extra current at the same time - the PSU would shut itself down to protect itself (and the rest of your system) from heat, or component failure.

If I were running a rig which used 2 GPUs which specify that they need 200W, I would use AT LEAST a 600W PSU. Like in your second example - where you used the 750W PSU and 2 Nanos were OK, but 3 were not - for 3 x 200W GPUs I would probably use AT LEAST an 850W PSU, or preferably a 1000W PSU.  

Seasonic Platinum 460W delivers 38A (456W) of current to its 12v Rail.
Its Stable 80% is 364.8W which is way below 400W, equals instability.

Seasonic Seasonic X Series 750W has 62A (744W).
80% is 595.2W, just 4.8W below 600W, still not enough juice.

This online tool may help you http://www.coolermaster.com/power-supply-calculator/, that is PSU online calculator, you just need to input any device you are using and the system will give you PSU wattage recommendations.

You must always monitor how much electricity your power supply is using, if not then you are doing a huge mistake, remember than you can't overload your power supply by 20% of its maximum output.

I checked the Seasonic X 750: it's a monorail 12V / 63 A.

Hi,

Seasonic 460 Platinum
Seasonic 750W Gold: X series SS 750 KM

make and model of psus  please

Hi,

My PSU don't seem to be able to hold the power on the label. When I put some wattage in them they STOP.

Test 1: 460W Platinum PSU.
- 1x Nano at 200W : OK
- 2x Nano at 400W: immediate stop of the PSU

Test 2: 750W Gold
- 2x Nano at 400W: OK
- 3x Nano at 600W: immediate stop the of the PSU after 5 seconds

Watts measured at the wall plug. Running with a Celeron G3930, idle power consumption 20W (included in the data above)

Setup: all GPUs on risers. Each riser is powered by an individual Molex cable or individual PCI-e 6 pin cable.

Question: what's happening? I tried changing risers and this did not fix the problem.
Thanks