Bad input lag/desync issue: Testing with AW2521H 360Hz monitor w/ Nvidia latency module

Separate area for niche lag issues including unexpected causes and/or electromagnetic interference (ECC = retransmits = lag). Interference (EMI, EMF) of all kinds (wired, wireless, external, internal, environment, bad component) can cause error-correction latencies like a bad modem connection. Troubleshooting may require university degree. Your lag issue is likely not EMI. Please read this before entering sub-forum.
Forum rules
IMPORTANT:
This subforum is for advanced users only. This separate area is for niche or unexpected lag issues such as electromagnetic interference (EMI, EMF, electrical, radiofrequency, etc). Interference of all kinds (wired, wireless, external, internal, environment, bad component) can cause error-correction (ECC) latencies like a bad modem connection, except internally in a circuit. ECC = retransmits = lag. Troubleshooting may require university degree. Your lag issue is likely not EMI.
🠚 You Must Read This First Before Submit Post or Submit Reply
spoidah
Posts: 27
Joined: 20 Feb 2021, 04:34

Re: Bad input lag/desync issue: Testing with AW2521H 360Hz monitor w/ Nvidia latency module

Post by spoidah » 06 Mar 2021, 02:21

I am now pretty certain I know what our issue is.

https://www.energynetworks.com.au/asset ... upply1.pdf
Read pages 35-51 if you want a comprehensive list of potential issues that arise from power, I'm gunna focus on 3 that I think are happening. Some people may not have electrical noise on top of the first 2 issues, but I certainly do.

1 is voltage imbalance.
2 is harmonic distortion.
3 is electrical noise.

The TL;DR version of it is:

Voltage imbalance - Poor balance between phases cause issues with power factor, which can mess with clock speeds, but poor phase balance also creates harmonic distortion.

Harmonic distortion - Leakage voltages, excessive heating for things like chargers and high power draw cables. What I'm EXTREMELY interested in here is inter-harmonics. Basically this can disrupt the functioning of ripple control devices, essentially sending harmonics into computers and networking equipment. It also creates slight light flickering in response to things turning on in the house, audible noise in audio equipment AND vibration in induction motors. This fits with my theory AND symptoms of the issue absolutely perfectly. I'm so, so certain this is the issue.

Electrical noise - little bit of distortion on the screen and some audible noise on audio equipment.

Anyway, I don't want to overload the thread with a massive wall of text here, but here's an article with very, VERY interesting implications.
https://ccaps.umn.edu/documents/CPE-Con ... monics.pdf

I'll drop in a few cliff notes:
"Interharmonics, like harmonics, add additional signals to the power system. These additional signals can cause a number of effects, particularly if they are magnified by resonance. The wider the range of frequencies present, the greater the risk of resonance. Many of the effects of interharmonics are similar to those of harmonics, but some are unique to interharmonics as a result of their non-periodic nature."

"Effects of interharmonics similar to those of harmonics caused by an additional signal superimposed on the fundamental can be separated into three categories: overloads, oscillations and distortion. The effects of overloads include additional energy losses that can contribute to heating, overloading filters or other system components and current transformer saturation. Depending on their frequency, these additional signals can cause oscillations in mechanical systems, acoustic disturbances, or interfere with telecommunication signals. Distortion of the fundamental frequency waveform can interfere with the operation of equipment synchronized with system zero-crossings or dependent on a consistent crest voltage, such as fluorescent lights, timing devices and some electronic equipment."

"The effects of interharmonic distortion can be mitigated using three methods that are also applicable to harmonic distortion: (1) reducing emission levels, (2) reducing load sensitivity and (3) reducing the coupling between distortion generating equipment and sensitive loads. The wide band nature and variability of the interharmonic distortion emitted from certain types of loads can make all three mitigation methods more difficult for interharmonics than for harmonics.

Reducing the coupling of interharmonic producing devices and sensitive loads is usually done with filters. Filtering can be practical when there is a single, or a minimal number of, interharmonic frequencies of concern. When there are multiple interharmonics of varying frequencies filtering may not be practical. Passive filters use low impedances at targeted interharmonic frequencies to shunt interharmonic currents to ground. Filters, especially lower loss undamped filters, can significantly amplify non-targeted frequencies"
Last edited by spoidah on 06 Mar 2021, 04:10, edited 1 time in total.

spoidah
Posts: 27
Joined: 20 Feb 2021, 04:34

Re: Bad input lag/desync issue: Testing with AW2521H 360Hz monitor w/ Nvidia latency module

Post by spoidah » 06 Mar 2021, 04:16

blackmagic wrote:
06 Mar 2021, 03:57

can these things mess with hitreg and affect the spray, accuracy in games ? causing low dmg and ghost bullet's ?
giving disadvantage in online games ? like messing with the peeking advantage and timings...?

if yes...

what exactly happen with the packets ? are they damaged through this or just delayed ?

i'm just curious and most interested in things what happens really between server and clients if someone experience this noises...
are this people get some kind of desync through this noises ? is this possible ?

sometimes i have this feel that the whole game engine is affected here and things are just like not running accurate or stable...that my feelings about my issue that i experience here.
Absolutely. I amended the post a little more. The effects of interharmonics are pretty severe. From smaller problems like introducing ripple into DC powered electronics (i.e. modems, routers, computers, computer monitors etc.), they can also be damaging if there's a wide spread of frequencies, it can cause harmonic resonance events https://onlinelibrary.wiley.com/doi/10. ... 887059.ch9

(more info on harmonic resonance here: https://www.ecmweb.com/archive/article/ ... latile-mix )

EMI has been the focus for a long time, but EMI is merely a symptom (of harmonics and interharmonics on AC power networks) that causes its own problems, it's not the cause of our problems in itself.

spoidah
Posts: 27
Joined: 20 Feb 2021, 04:34

Re: Bad input lag/desync issue: Testing with AW2521H 360Hz monitor w/ Nvidia latency module

Post by spoidah » 06 Mar 2021, 05:00

blackmagic wrote:
06 Mar 2021, 04:36
this all is interesting...
thanks for your input on all this and helping people.


i find many posts in different languages where people describe that rebooting or turn off/on there routers are making things better for some time...


same thing are happening here too but it don't works always and that what confuses me all the time but there clearly some effect and things getting really better by just a reboot pc/router or messing around with the power plans here...

i think this all can't be just placebo or coincidence.
Yeah, I strongly suspect that has something to do with the capacitors within the electronics initially being able to compensate for some of the ripple, but they become saturated and don't function properly after being on for a period of time. I'm not certain how long that would be, but my experience has been usually within 30 minutes.

One very big problem with interharmonics is that power companies do not have mandatory standards for keeping interharmonics under control, and methods for testing it are very difficult, while using oscilloscopes to look at waveforms is not super easy in itself, it's even harder than that. As the article says, testing for 'normal' harmonics requires "use a phase locked loop to synchronize the measurement... This accurately represents the waveform only if it does not contain any non-periodic (interharmonic) components ...The measurement of interharmonics, which are non-integer multiples of the fundamental frequency and may vary with time is more difficult"
Basically, normal testing equipment that electrical engineers use may not actually detect them, though you can detect them with an oscilloscope https://grouper.ieee.org/groups/harmoni ... hfinal.pdf.

Essentially, an electrical engineer will need to test with non-standard equipment in a non-standard way (though they or you can do a 'budget' test using an oscilloscope and by using the correct window functions - article on how to configure the oscope here https://scialert.net/fulltext/?doi=itj.2013.1004.1010 - and even then, you may not be able to get your power company to fix the issue (since they aren't obligated to fix it, no matter how bad it may be). It does look like you're able to filter harmonics, interharmonics and subharmonics through the use of specially designed active filters or through multistage passive harmonic filters with dampening. Don't commit to buying anything unless you're sure it can filter interharmonics.
More data on harmonics and interharmonics here if you want to do a bit more reading. https://www.dranetz.com/wp-content/uplo ... efacts.pdf

Either way, it's looking like this is an issue where you have to spend money getting an electrical engineer to check stuff out, or buy some very expensive oscope equipment yourself and test (though if you're not a licensed professional, power companies won't take you seriously), and still might not be able to get a solution. Another major issue is that it is not an easy thing to investigate if you're considering moving to a new property and want to avoid places with the same issue.
Last edited by spoidah on 07 Mar 2021, 05:50, edited 3 times in total.

spoidah
Posts: 27
Joined: 20 Feb 2021, 04:34

Re: Bad input lag/desync issue: Testing with AW2521H 360Hz monitor w/ Nvidia latency module

Post by spoidah » 06 Mar 2021, 05:45

Since we suspect we're dealing with interharmonics, and interharmonics can mess with ripple controllers (articles only mention ripple controllers from poco equipment, but I think we can safely say it affects ripple controllers in PSU's too, since they mention it causes electronics to misbehave), it means we're dealing with DC ripple current in our PC's.

Ripple current is a little different from ripple voltage, because it's essentially harmonic distortion inside your PC. It'll cause filtering components to saturate over time, which then increase emissions of things like EMI (which may cause issues with data corruption and retransmissions, increasing system latency), can cause overheating of components, and can trigger little voltage events that your mobo will AUTOMATICALLY try to throttle down to protect components. It doesn't matter how good your cooling is, if your mobo detects 1.8V (even for a split second) from your CPU it'll throttle down to protect it.

We can offset the issue and keep it manageable with extensive, across the board underclocking and reducing power draw to an absolute minimum. This may mean using only 1 SSD or 1 m.2 SSD, no extra stuff plugged into PCIe slots, e.g. NIC's or sound cards. Downclocking GPU as low as possible too. Maybe not with MSI afterburner, try to use your GPU manufacturers software, I tried using afterburner to downclock my AORUS GPU, and the voltages actually increased even though the clock speeds were slower...

Edit:
Alright, did some tests on my idea about using an 'ultra-minimalist setup', only ran PC on 1 m.2 SSD, unplugged extra USB devices, disabled XMP mode, disabled my motherboards sound controller, disabled my mobo's integrated GPU, disabled my mobo's integrated NIC and DAC USB hub, disabled CPU turbo boost and ran at factory 3.7GHz, downloaded my GPU's software and downclocked it, etc. I then tested using auto settings vs manual and a variety of LLC's.

At no point did the stutter alleviate when shooting at enemies. I couldn't figure out why I could play in a full server, shoot at empty walls and experience ZERO stutter, but the instant I attempted to shoot at enemies the game would stutter, and it wouldn't show anything wrong with loss, choke, ping, or issues with frametimes or frame rate drops.

I then realised what I had overlooked; this is a system-wide issue. I put 2 and 2 together, as I previously had an older PCIe NIC that overheated at stopped working when I was doing iperf3 UDP tests. NIC's have chips that process data going to the CPU, if there's voltage issues due to ripple, something low-key like shooting at a wall is only sending a bit of traffic and receiving some baseline traffic about player positions. Relatively little for an NIC to process there. BUT, if I'm shooting at an enemy, I'm sending and receiving a whole lot more data, while still receiving the baseline level of traffic the game sends. The poor little chip inside the NIC needs to process this data, which increases its power draw, it's not long before it's experiencing voltage events and throttling to prevent itself from burning out. Bottom line is disable ALL processing from within the NIC, disable interrupt steering, flow control, anything related to offloading, large send offload, jumbo packets, coalescing, etc. EVERYTHING and anything that requires the chip in the NIC to do processing of any kind.

This greatly reduced stutter, but I was still using a high-end 10Gbps PCIe NIC, and I think the amount of power required to keep it running was causing issues. Instead, I used a USB hub with a ethernet adaptor and plugged it into my front USB panels, and then disabled the processing. NO stutters. None. I'm going to make another video of this.

Inkd
Posts: 1
Joined: 04 Jul 2021, 20:07

Re: Bad input lag/desync issue: Testing with AW2521H 360Hz monitor w/ Nvidia latency module

Post by Inkd » 04 Jul 2021, 20:29

Hey mate, I'm getting similar issues with the same screen, Alienware 360hz. I recently purchased an i9-11900k with 3080 graphics card and don't understand why I am getting weird input lag and stutters in gun fights.. I would think on such a good pc i would never have these problems.. I am trying to understand what you did to fix it with what you have written. Any chance you can explain it further to me... sorry if i sound stupid lol

MegaMelmek
Posts: 235
Joined: 21 Jan 2021, 12:54

Re: Bad input lag/desync issue: Testing with AW2521H 360Hz monitor w/ Nvidia latency module

Post by MegaMelmek » 12 Jul 2021, 05:07

Just buy external LAN connect to the USB - 100% there is less inputlag but but still feel wierd. But is way more playble than before. What is next get external GPU…? These PC components are crap today. Can some one measure that?

Tin1017
Posts: 21
Joined: 06 Apr 2021, 20:51

Re: Bad input lag/desync issue: Testing with AW2521H 360Hz monitor w/ Nvidia latency module

Post by Tin1017 » 13 Jul 2021, 13:21

CPU overvoltage in bios? Would that help?

woodyfly
Posts: 91
Joined: 03 Jul 2020, 07:53

Re: Bad input lag/desync issue: Testing with AW2521H 360Hz monitor w/ Nvidia latency module

Post by woodyfly » 11 Nov 2021, 16:24

any updates on how that external usb to lan card worked out?

Eonds
Posts: 262
Joined: 29 Oct 2020, 10:34

Re: Bad input lag/desync issue: Testing with AW2521H 360Hz monitor w/ Nvidia latency module

Post by Eonds » 11 Nov 2021, 16:59

spoidah wrote:
21 Feb 2021, 16:00
EDIT2: I've completely overhauled the first post. I am now quite sure about what is causing our issues, it is a very sophisticated problem with power that causes EMI and various other issues we've all assumed is the cause of our problems. The long and short of it is we are dealing with harmonics, but not the 'normal' kind.

The issue may present itself as electrical noise from the 5KHz-20MHz range. The higher frequency noise in the MHz range likely isn't the cause of our problems, but it probably exacerbates it. I believe the main issue lies in the Hz and KHz range, and is caused by interharmonics and supraharmonics. It's normal to get some noise in those frequencies, but there's a threshold where they interfere in the power distribution and cause problems with electrical components (namely saturation of things like capacitors and transformer cores, which creates a snow-ball effect of larger and larger problems). Distortion of the fundamental frequency waveform can cause issues such as clock drift and ripple current inside your PC. Despite all the protective mechanisms inside a PSU, there are vulnerabilities to power quality issues, e.g. inductors and capacitors. These components are rated for a certain amount of current, and with harmonic distortion and subsequent low power factor, you can end up with saturation, and the components no longer do their 'job' of ensuring a stable flow of current. The same goes for things like online UPS's and power filters. Exceed certain thresholds and you'll end up with more distortion from those devices than you would directly plugging it into the wall (interharmonics are renouned for their difficult nature, they can easily overwhelm filters, AND incomplete filtering can result in the frequencies and effects being AMPLIFIED).

You can either read the journal article yourself (Interharmonics: What They Are, Where They Come From and What They Do) https://ccaps.umn.edu/documents/CPE-Con ... monics.pdf, or you can read my posts on page 4 where I post some of the TL;DR's and refer to other articles too.
.

Shoutout to nug, unixko, numberfive and a bunch of the others in the discord, we share journal articles and bounce ideas off each other to sorta educate ourselves and go down investigative pathways.

THE TL;DR is that interharmonics can mess with ripple control methods, meaning it'll INDUCE RIPPLE CURRENT inside household electronics, and can present itself alongside other issues like differential-mode noise, meaning it can't be filtered by conventional means, including isolation transformers and double conversion UPS's (unless the UPS's are medical grade and are engineered to keep the ripple controllers from being affected, though I'm not sure even those can stop it, options are quite limited, it seems harmonic filters are pretty much your only option, but they need to be multistage filters with dampening if they are passive harmonic filters, or you go the active harmonic filter route you need to be sure they are rated to deal with interharmonics and subharmonics).

Anyway, ripple current inside your PC means there's harmonic distortion inside your PC. Once the capacitors in the PSU and then the mobo are saturated, components inside the PC affected and saturated too, they'll emit much more EMI than normal, they'll emit more coil whine than usual, they'll overheat, they'll experience voltage overload events if there's harmonic resonance or slightly below resonance, depending on the mobo you'll either have damaged components or the mobo will throttle those components to protect them. It doesn't matter how good your cooling is, if you CPU gets a split-second of 1.8V the mobo will throttle.


phpBB [video]


(this is the original post)
Here we go folks, did some input lag testing with MSI afterburner and RTSS for your viewing pleasure.

As you can see, the lag/stutter/input lag issue doesn't seem linked to frametimes, going from 0.5 to 7.5ms isn't that big a deal immediately after killing a bot. The input lag also isn't 100% linked to mouse clicks, but pretty frequently I get unlucky and it corresponds perfectly with a lag spike, and I get values ranging from 100-400+ms. (when the monitor just shows x's, it means it was over 400ms input lag).

The issue also seems to vary in severity on different game engines. On games like aimlab and CS:GO (at least when offline) it's not too bad, but on games like Kovaak 2.0, PUBG, Battlefield etc. it's pretty terrible. When playing online on CS:GO, it'll start off relatively smoothly, but after about 40 minutes of playing, things get a lot more stuttery, and it ends up feeling like I'm dragging my mouse through mud and people are just warping around the place e.g. youtube com/watch?v=PcgOpLRh0do

Additionally, I know things are not right, because when I brought my mouse and mousepad to a friends house, with him using almost a carbon copy of my rig, I couldn't use my normal sensitivity - 2200eDPI, I had to use 1400eDPI, and the tracking and general gameplay felt so much better, much more crisp, and I was just bullying people with 1 taps.

EDIT: I have a potential method to help reduce these mouse tracking/input lag/stutter issues: Long story short, when you notice the issue is at it's peak crappiness, try underclocking, using a frequency about 300-400MHz below the 'intel turbo boost' default (e.g. i7 8700k is 4.7GHz, so I'm using 4.3GHz), with a medium to high LLC (e.g. level 5-6 ASUS, or 'high' to 'extreme' with gigabyte, but using your CPU VID as a point of reference for your vcore voltage instead of normal-style overclocking.

People usually ignore CPU VID because it's the value your mobo thinks the CPU needs to function, which is usually too high, but I'm thinking we can use the VID to get an idea of how the issue is affecting our CPU power draw, and approximate an underclock that allows 'additional capacity' for voltage for when we're being affected by this power issue - BUT with a twist, using CPU VID to figure out what vcore your mobo thinks the CPU needs, and aiming to keep the CPU VID lower than 85% of your CPU's 'safe upper limit' vcore voltage, by using low enough frequency, LLCs and vcore settings to facilitate this. (e.g. my 8700k's safe upper limit is 1.4V, 85% of that is 1.19V, I want my CPU VID to be lower than 1.19V, so I used a high LLC and lowered my frequency bit by bit until I saw the CPU VID was under 1.19V, I then set my 'maximum allowed vcore' to 1.19V)

If you want to try this yourself here's how:

  • 1. Set your CPU frequency/clock speed 300-400MHz lower, set a high-ish LLC, KEEP your vcore on auto, and then load up windows. Using a monitoring program like hwinfo, look at your CPU VID, spam a few clicks on desktop, play a game, then do like 5 minutes of stress testing with prime95.

  • 2. Look at the maximum CPU VID your CPU reached, and also the vcore, the highest value you see is your new baseline vcore voltage. Is it less than 85%? If no, use a lower CPU frequency/clock speed.

  • 3. Now that you're at a CPU frequency that's low enough for your VID to be less than 85% the safe upper limit, set your vcore to that limit. Enjoy smooth gameplay. You can try to increase your CPU frequency a little bit and get more performance out of your PC, but when the interharmonics are at 'peak awful' territory, you may not have left yourself enough 'overhead' to avoid having issues. Also, if you want to get rid of the stutters, you'll need to read the stuff on page 4 (control+f, search for ripple current).



Here's an early attempt at figuring out my ideal underclock. I wasn't doing p95 tests and looking at VID then, and the underclock wasn't quite right, but the difference is still very noticable. Look at the difference in mouse control from 1:40 and 2:17).


phpBB [video]

Why under lock the frequency when you can use techniques like spread spectrum clocking that modulate the frequency to reduce peak to peak emi spikes. There’s multiple spread spectrum settings in bios that can help. Most noticeably rfi 6% on a + prefix can help some. If not try a - prefix. You can also mess around with pll ssc but don’t go to 2% or 0.0%. Trial and error. There’s also things like vrm spread spectrum, SRIS, BCLK spread spectrum, disable bclk spread spectrum lol.

MontyTheAverage
Posts: 81
Joined: 11 Nov 2021, 06:39

Re: Bad input lag/desync issue: Testing with AW2521H 360Hz monitor w/ Nvidia latency module

Post by MontyTheAverage » 16 Feb 2023, 08:07

This is probably is the most likely cause of my issues. I have experienced similar instances described by OP. Feel like this thread has very important info that can be used to follow up on finding fixes. I haven't any yet besides the nuke option of buy everything new and moving.

Post Reply