PCIe +12v Input Voltage Droop- How Much is Too Much for GPU?

[LeSandwich]

I have a Gigabyte RTX 3070 with a Phanteks Revolt Pro 1000w; more than enough for everything in my PC. anyway, I've monitored my GPU Rail Voltages and their behaviors, and noticed something with the PCIe 12v Input Rail Voltage (with HWInfo of course) while playing Destiny 2


normally my PCIe 12v Voltage is 12.050v; however, once my Power Consumption exceeds 100 watts, the GPU Voltage will increase above 1v, which will then cause the PCIe 12v Input Rail Voltage to droop down to 11.86-11.89v (the exact number can vary but that's the range it always falls to once the GPU Voltage is greater than 1v)


the lowest number I have seen while gaming (Destiny 2) is 11.856v, but 9 times out of 10, the voltage of the PCIe rail will be 11.887-11.89v; sometimes it drops briefly or sometimes it will linger there for a few seconds, depends on how long the voltage remains above 1v, which usually isn't too long



it's absolutely within ATX spec for sure, and yes "software can be inaccurate", but let's assume it's telling the 100% truth right now about these GPU Rail Voltages. is this voltage droop too much on the PCIe 12v Input Rail? 12.05v to 11.86-11.89 (with an absolute minimum of 11.856) after exceeding 100 watts...I've heard you should never drop more than 0.2v on the line under load and 12.05 - 0.2 is 11.85, so I'm confused and concerned?


under benchmarks with highest settings, at 230w, the PCIe line has always been observed at 11.80-11.85v during the benchmark, for further context. so I haven't really universally gone below 11.80, or at least below 11.879 on the PCIe even at max wattage on the card, and that's not really my realistic gaming power consumption. also the 8-pin and 6-pin voltages never sag that far in my games either; they're always fairly stagnant at 12.0v and 12.1v

 

[DR4G00N]

"software can be inaccurate"

This is likely your answer, you really have to check it with a multimeter to be sure.

I remember when I was running my pair of 780 Ti's my current 1300 G2 would apparently drop from 12.15 to 11.8V under load according to software but in reality it just went from 12.10 to 12.05V.

 

[Vya Domus]

It's fine. If it was an issue you'd know because it would crash your system.

 

[Frick]

Where did you read a 0.2V drop under load was really bad?

 

[freeagent]

Maybe jiggle the 24pin a little with the system loaded, sometimes that plug can wear, and needs a little pressure for a good connection.

 

[ir_cow]

Dropping to 11.8 underlaod is pretty normal. I've found 11.6 is when the voltsge it too low and crashes the computer.

 

[LeSandwich]

Where did you read a 0.2V drop under load was really bad?

that’s why I don’t want to worry about it, I think it was on some kind of support forum or a reddit tech post?

considering I’ve never found that kind of statement again, I question its legitimacy but it just floats around in my head

 

[R-T-B]

that’s why I don’t want to worry about it, I think it was on some kind of support forum or a reddit tech post?

considering I’ve never found that kind of statement again, I question its legitimacy but it just floats around in my head

Well it's nothing to worry about anyways. Likely just "internet experts" doing their finest (not really lol).

 

[freeagent]

Likely just "internet experts"

Aren't we all

 

[LeSandwich]

l

Well it's nothing to worry about anyways. Likely just "internet experts" doing their finest (not really lol).

lol thanks, it just gets confusing with so many conflicting reports and stuff

someone else (not here) stated that they only really see a problem once the voltage drops below 11.75v while pulling large wattage so idk, maybe 11.85-11.89v really isn’t as big a deal as I’m thinking

I play Destiny 2 with pretty Medium settings and vanity options set to Low or turned off entirely yet it can send my wattage higher and drop my voltage lower than games I’m playing with High settings lol, that’s why I got worried

 

[R-T-B]

Aren't we all

I mean, some of us have careers to back it up. And github profiles. But yeah, I do spend a lot of time on the internet.

 

[LeSandwich]

It's fine. If it was an issue you'd know because it would crash your system.

I was mainly concerned about the value being too close to a “danger zone” or a voltage that can start causing problems

aside from the ATX spec I mean; like how the other person stated that 11.6 is where they’ve found the stability to start going wonky for example

 

[ir_cow]

aside from the ATX spec I mean; like how the other person stated that 11.6 is where they’ve found the stability to start going wonky for example

I found out 11.6 was the problem zone when I was having crashes a while back. Probing the PCIe cables relieved the issue. Yeah, not talked about often, but extension cables can have a nice voltage drop on them. Took them out and it went back up to 11.9~.

 

[LeSandwich]

I found out 11.6 was the problem zone when I was having crashes a while back. Probing the PCIe cables relieved the issue. Yeah, not talked about often, but extension cables can have a nice voltage drop on them. Took them out and it went back up to 11.9~.

yeah typically my PCIe voltage is ~12.05v but on fair occasions, when the GPU rises to 0.8v or 0.9v, the PCIe will droop to 11.9v

in some games it’s more common than others, but Destiny 2 is really the only game I’ve encountered where the GPU voltage rises fairly often above 1v and the PCIe droops to 11.8v

as mentioned above, I really only play Destiny 2 on Medium graphics with vanity settings switched to Low, but it insists on taking a good bite of power occasionally.

just gonna keep hoping that my lowest drop of 11.856v is nothing to worry about

Maybe jiggle the 24pin a little with the system loaded, sometimes that plug can wear, and needs a little pressure for a good connection.

it’s in pretty good; the rig is fairly new (built in February), and I do remember that in Destiny 2 and benchmarks, the PCIe has always kind of drooped to the 11.8v ranges once the GPU voltage hits 1v and the Power Draws goes over 100 watts

I didn’t instantly put it all together, I just saw the 11.8v values and freaked out back then but now I see the connections. I guess my main concern is that I’ve never seen the minimum of 11.856 before yesterday and I’m just not sure if it’s placebo or if the PCIe drops/voltage spikes more often now

might be placebo idk, since Destiny 2 is the only game that causes this behaviour as far as I can tell. and benchmark results/behaviors are all the same

 

[LabRat 891]

AFAIK, the little Vdroop isn't a concern.
If you had an oscilloscope, you could see what the jitter, noise, and transients are like; which, would be where concern may lie.

 

[LeSandwich]

AFAIK, the little Vdroop isn't a concern.
If you had an oscilloscope, you could see what the jitter, noise, and transients are like; which, would be where concern may lie.

so reaffirming that 12.05v to 11.85v isn’t a ‘big’ drop of voltage? not enough to cause concern at all?

 

[freeagent]

so reaffirming that 12.05v to 11.85v isn’t a ‘big’ drop of voltage? not enough to cause concern at all?

You should be ok. I have had problems between 11.4-11.6.

If your 3.3 is down in the 2.8-2.9 area you will also have problems. The 5v doesn't like to be down in the 4.6 range too.

 

[LeSandwich]

You should be ok. I have had problems between 11.4-11.6.

If your 3.3 is down in the 2.8-2.9 area you will also have problems. The 5v doesn't like to be down in the 4.6 range too.

yeah 3.3v according to HWInfo (and Bios) is pretty much always 3.32v and the 5v is a constant 4.980v, taken with a grain of software salt

the 12v on HWInfo fluctuates between 11.884 and 11.980, no other value

then of course there’s the main topic of conversation which is the PCIe 12v Input Rail, which behaves as described. 8-pin and 6-pin voltages rarely ever drop below 12v as well, only doing so if I’m benchmarking like over 180-200w

 

[LabRat 891]

so reaffirming that 12.05v to 11.85v isn’t a ‘big’ drop of voltage? not enough to cause concern at all?

Depending on other details/circumstances, it's totally fine.
(Also, I'd like to reinforce: never 'trust' software voltage readouts. I had a 5600 degrade in an Asus board; suspect underreported voltage.)

If I had a 'snappy' DMM and it was reading rapid swings under sustained load (with noticeable stuttering on-screen), I might try and investigate further.

You could do some pedantic things to try and reduce impedance/resistance on the line... But, seriously not worth it. It'd be a potentially risky exercise in 'self-enrichment', with little to no payoff.

 

[freeagent]

I had a 5600 degrade in an Asus board; suspect underreported voltage.

I beat the piss out of my CPUs on Asus boards, no problems to report

I think something else is/was amiss

 

[OneMoar]

11.8 is FINE but I would question the LLC capablity of a psu that is droping 0.2v on a 100W load

but check it with a meter could be the sensors on card are way out of wack or there is something funky happening on the cards vrm stages

 

[LeSandwich]

Depending on other details/circumstances, it's totally fine.
(Also, I'd like to reinforce: never 'trust' software voltage readouts. I had a 5600 degrade in an Asus board; suspect underreported voltage.)

If I had a 'snappy' DMM and it was reading rapid swings under sustained load (with noticeable stuttering on-screen), I might try and investigate further.

You could do some pedantic things to try and reduce impedance/resistance on the line... But, seriously not worth it. It'd be a potentially risky exercise in 'self-enrichment', with little to no payoff.

I have no consistent or prominent stutters, and yeah I’d rather not bother with the resistance reduction stuff

wdym by “depending on other circumstances”, I’ve monitored the software and behavior in games, on idle, and in benchmarks an embarrassing amount, I can probably provide whatever context is necessary

but in general, to restate what I’ve said in random responses: I play Destiny 2 on Medium-Low settings which is where this voltage droop happens. on Higher settings and refresh rates, instead of occasionally drooping down to 11.86-11.89 it’s pretty much always on a ‘default’ of 11.87

in Heaven Benchmark, with Highest settings, it will obviously pull max wattage and I’ll look at 11.80-11.85v; same results when tested with uncapped fps

8-pin and 6-pin voltages pretty much never drop below 12v under gaming loads; 3.3v line is always at 3.3 and 5v line is always at 4.980v (these 2 are most likely to be inaccurate with software though I imagine)

11.8 is FINE but I would question the LLC capablity of a psu that is droping 0.2v on a 100W load

but check it with a meter could be the sensors on card are way out of wack or there is something funky happening on the cards vrm stages

I usually don’t play games that draw over 100w, it’s just that Destiny 2 sometimes does and the GPU Voltage will increase and the PCIe line will droop, etc.

even Elden Ring doesn’t really go near 100w draw, hovers around 60-80w

under a max settings Ultra/Extreme/x8 Heaven Benchmark with uncapped fps, the PCIe will sag by around 0.25; lowest I’ve ever seen is ~0.26 to 11.794 but that was a massive power draw for the card

under max settings Heaven Benchmark with 120fps cap, the PCIe droops typically to 11.80-11.85v; these HB results aren’t really indicative of my gaming loads but Destiny 2 may sometimes draw 120w and cause the 11.87-11.89v sags

I believe my biggest gaming droop of 11.856 was caused by the wattage going up to around 132w before falling back to normal

 

[LabRat 891]

I beat the piss out of my CPUs on Asus boards, no problems to report

I think something else is/was amiss

Sorry for expanding on further off-topic'ness but...

You may well be correct.
While I was troubleshooting my 5600, I stumbled upon reports of 'early batch' Zen 3 SoCs having an inexplicable and higher-than-normal failure rate.
It either wasn't terribly widespread, or AMD+partners did a dang good job on PR control.

Another odd thing (that maybe someone else that's RMA'd w/ AMD can expound on): My CPU's Serial was totally unrecognized by AMD. Only after providing extreme detail and proof of purchase and ownership, was I able to get my RMA authorized.
Dunno if I can really say that's a 'bad thing' towards AMD, but it was 'odd' to me.

 

[LeSandwich]

11.8 is FINE but I would question the LLC capablity of a psu that is droping 0.2v on a 100W load

but check it with a meter could be the sensors on card are way out of wack or there is something funky happening on the cards vrm stages

btw, sorry to return to this YET again, but are you insinuating a fault with the PSU or the VRMs? or could it just be harmless bad luck with my exact power supply and motherboard’s capabilities

 

[LabRat 891]

btw, sorry to return to this YET again, but are you insinuating a fault with the PSU or the VRMs? or could it just be harmless bad luck with my exact power supply and motherboard’s capabilities

Not exactly a 'fault', but he was speaking to the PSUs ability/quality to 'load compensate'.
It's mere physics that Voltage droops more, the more current is being demanded; the PSU is supposed to have "Load Line Calibration" or a feedback-mechanism to proportionally 'up' the voltage it is supplying (in compensation for load).

what do you mean by “depending on other circumstances”, I’ve monitored the software and behavior in games, on idle, and in benchmarks an embarrassing amount, I can probably provide whatever context is necessary

Honestly... I only will say that there 'can be' unseen, unexpected and/or otherwise, (commonly-considered) 'Pedantic' factors.

Spoiler: Mini-rant/whining Warning

Whenever I delve into those details of electrical engineering, I get flamed and torn to shreds by experts. My under-experience and under-education leaves me utterly incapable of communicating constructively with elitists (which, I don't even 'blame', as idiocy and purposeful spread of dis/mis-info is rampant)