[SOLVED] issues with running 2 gpus at the same time (Not SLI)

[Notyett]

i got 2 gpus in my pc
1660 super overclocked for gaming
3060ti heavily underclocked for mining
my 1660 super loses 30%+ fps if i put power limit at anything higher than 60, so i unplugged my 3060ti and my main gpu is now working well (did a lot of troubleshooting before i realized the issue)


so im assuming this is a power delievery issue, and i already have 3 suspects:

1-(unlikely) my motherboard is asus z390 prime a
2- my old 620 cooler master psu, even tho i did look online calculators on seasonic/newegg/coolermaster and other websites and they all suggested 550-600 watts
3- prime suspect imo is the SINGLE pci 8 pin cable coming from the psu and powering BOTH of my gpus , i did my research before doing that and i found out that pci 8 pin holds up to 150 watts and since the gpus gets 75 watts from the slot itself it shouldve been fine (1 cable out of PSU plugged into 2 gpus)

maybe none of my guesses are correct and its just some toggle in the bios, hopefully
id like any inputs honestly, since i wasnt able to find anything online


Specs:
Motherboard: Asus Z390 Prime A
Ram: 8x2GB 3200MHZ CL16
CPU: 9600k
PSU: Cooler master 620W
GPU: 1660 super , 3060 ti secondary

Done complete reinstall of drivers using DDU

 

[Historical Fidelity]

Definitely it’s your power supply and I wouldn’t use the same pciexpress power cable for 2 different gpu’s, given the different power requirements and power modulation differences I can definitely see electrical interference being a possibility. At any rate 620 watts is definitely not enough as transient power requirements for both your gpu’s is much greater than the average power requirements listed on the gpu specs page. I’d recommend an 850-1000 watt power supply and use different power cables for each.

 

[Karadjgne]

2- my old 620 cooler master psu, even tho i did look online calculators on seasonic/newegg/coolermaster and other websites and they all suggested 550-600 watts

3 strikes and you are out of luck.

1. That's an Old group regulated psu, not exactly a shining example of decent, had very mediocre outputs and wasn't really a 620w psu.
2. Faith in online calculators.
3. Suggestion of 550w - 600w apples to only the 3060ti.

3060ti suggested is 575w. Power consumption for 1660ti FE is right at 120w, so figure upto 150w for aftermarket OC cards.

You need a very decent 650w like Corsair RMx at a very minimum, with preference being a Platinum rated psu since your mining is a constant load.

The only way you'd get away with a lesser psu is if you gamed OR mined, not gamaed AND mined. But you'd still require a solid, reliable psu.

 

[Notyett]

3 strikes and you are out of luck.

1. That's an Old group regulated psu, not exactly a shining example of decent, had very mediocre outputs and wasn't really a 620w psu.
2. Faith in online calculators.
3. Suggestion of 550w - 600w apples to only the 3060ti.

3060ti suggested is 575w. Power consumption for 1660ti FE is right at 120w, so figure upto 150w for aftermarket OC cards.

You need a very decent 650w like Corsair RMx at a very minimum, with preference being a Platinum rated psu since your mining is a constant load.

The only way you'd get away with a lesser psu is if you gamed OR mined, not gamaed AND mined. But you'd still require a solid, reliable psu.

i wouldnt have thought a PSU manufacturer would sell you a less powerful PSU, im sure i put both gpus in those calculators,
my 1660 super tops up on the highest overclcok i can get at 140W no matter how many gpus in the system
my 3060ti is always underclocked, been like that since i installed it, it draws 140W max when its mining, but during these tests it maxed at 50W and usually idles at around 20W

i dont see why i should look at the tdp of 3060ti, since im not running it on stock settings, i never do, i dont even use it to output video

" The only way you'd get away with a lesser psu is if you gamed OR mined, not gamaed AND mined. But you'd still require a solid, reliable psu. "
thats exactly what im doing with these tests, and i still face this issue

heres something i did:

1- With both gpus installed i ran the benchmark on stock clock and got 39 fps
2- With only one gpu installed i ran the benchmark on stock clock and got 56 fps
3- With both gpus installed AGAIN i ran the benchmark on stock clock and got 49 fps
so somehow its now not as bad but still clearly limited

 

[Karadjgne]

i wouldnt have thought a PSU manufacturer would sell you a less powerful PSU,

View: https://m.youtube.com/watch?v=f6snWfd1v7M


They do it All the time. If you look, watch the 'rated' wattage vs the wattage at failure. You'll also find this isn't strictly limited to 'off brand' psus.

There's multiple instances where a manufacturer puts a claim on a psu, just to make it sound good 'bigger is better after all' attitude, but the platform itself and the component choices simply do Not support the claims. A good 620w psu should have at least 600w on the 12v rails, have at least a 6+2 and 6pin pcie with the better units having 2x 6+2pin pcie. I've seen (as have many others) upto 750w units with a single 6pin or 6+2pin, which just shows exactly how much faith in the 12v rail the manufacturer has, a 6pin good for 75w and 6+2pin at 150w, on a 750w rated psu.

 

[Notyett]

no i meant why would seasonic advise me to get 600 watts, when its supposed to say 700+ and they make more money ? thats what happened

either way my 8 years old PSU have never had any issues, i overclocked on it 2-3 generations of CPUS and GPUS, this is the first time i had a real issue with it and im still not sure its the problem (ive been running the 2 gpus like this for over a year now never seen any sparks whatsoever)

But i just ordered an xpg core reactor 850W because ill do that sooner or later, ill try to update this once i get it and test everything again

 

[Karadjgne]

Anything electronic has 1 of 2 states. It either works or it's broke. There really isn't anything inbetween. If a TV had a glorious picture but absolutely no sound, it's broke. It does not work. (discounting the deaf). Same goes for a psu. It can work great for years, then technology surpasses it, things like low voltage states being below what's necessary to wake from sleep (non Haswell ready psus), degrading to the point where it no longer supports the OC or values stated (caps do degrade with time, heat, use, just like a florescent bulb will turn purple at the tips). It technically might still work, same as the TV technically works, and it'd be ok for some, but realistically it's a hairs breadth away from complete failure.

That psu had a 1 year warranty when it was new.

Take the source into consideration. Using a Seasonic psu calculator, the expectation would be the use of a new Seasonic based psu, not a 8 year old group regulated CM value psu that's seen use with OC, still sees use with OC, has definitely suffered from degradation over 8 years of heavy usage, was never intended to be built with high grade components such as Japanese solid aluminium caps etc.

Right now, you'd be lucky to see 450w out of it, and thats right about where having both cards puts you, the cards do use power at idle, even if not in active use. Most cards run @ 15w, but OC versions or ones set to higher power plans by user OC or stupid motherboard software like Dragon Center or Asus Gpu Tweak, can see as much as 40w at idle. And that's assuming the second card isn't being used as a physX render etc.

DirectX 12 (native to Win10+) is mgpu based, not sli based. It could be nothing more than DX settings guaranteeing the 2nd card has 100w reserved, and leaving you short changed on the 1660ti as a result.

 

[Historical Fidelity]

+ using the same pcie power cable on 2 separate gpu’s is just asking for trouble

 

[Karadjgne]

+ using the same pcie power cable on 2 separate gpu’s is just asking for trouble

True. 75w/150w is an industry standard, but not an actual limit. A 6pin has 2x 12v wires, rated at 5A. Technically a 6pin is good for 120w, a 6+2pin is good for upto 180w.

Modular connectors use a 9A rated pin. Not all psu manufacturers use common sense with wiring, figuring on over compensation, but it's possible to have 120w from the gpu to try and pull through a single pin rated at 108w, and that can lead to issues.

 

[spentshells]

What will get you by will not offer you proper function.
I ran a 3060ti on a 550 watt psu using a 130 watt cpu.
It can be done and worked fine.

As mentioned above your pay is older.

Just get a new psu. If ya wanna be cheap a 750 watt superflower should work out.
Seasonic of the same size should work as well.

If I were doing g this I'd use an 850 watt psu, Silverstone or FSP