Zwift To Release Important Performance Bug Patch

Zwift To Release Important Performance Bug Patch

Traditionally, Zwifter complaints about riderless bikes, low framerates, and other goofy behavior have been chalked up to underpowered hardware. But that all changed in the past few weeks…

A Double-Edged Sword

Since early days, Zwift has been compatible with a wide range of devices including budget laptops, Android phones, 4th gen AppleTVs, and some older iOS devices.

That compatibility makes it easier (and more affordable) for people to begin Zwifting, since many people will already own a compatible device.

But it’s a double-edged sword.

Maintaining compatibility with a wide range of devices requires an investment of developer and artist time to optimize the experience across various platforms. When done right, this optimization delivers a lower-quality (but functional) experience on low-end devices and a high-quality experience on high-end hardware.

That optimization has never been perfect – there’s just no way to dial it in perfectly across the universe of devices Zwift supports. So there are times when hardware slips through the cracks, and an underpowered device struggles on Zwift, or a high-powered device delivers a “basic” experience because the game doesn’t know it can run at higher quality settings.

New Peaks, New Problems

While a smattering of complaints from low-powered “potato” users has become a daily expectation in Zwift forums, complaints of system crashes, riderless bikes, framerate drops, and slow ride clocks began to surface in much higher numbers last week. This major uptick coincided with the start of Tour de Zwift 2021 and its unprecedentedly huge events.

Riderless bikes from a recent Tour de Zwift event (taken on a high-end gaming PC)

And some of these reports were different from the usual “my potato has a low framerate in a 2,000-person event” complaints. Zwifters on high-powered PC’s were describing problems typically only seen on low-powered hardware. And some of the issues were different than typical large-event issues: many users complained that, after riding for 20 minutes, their elapsed time clock in Zwift only showed 5-10 minutes!

Something else was wrong… but nobody knew what. And we all hoped Zwift could figure it out, because it’s no fun celebrating Peak Zwift if it means more people are having Zwift problems.

Patch News

Then yesterday, Zwift CEO Eric Min posted a reply to our latest Peak Zwift post on Facebook:

This was great news! After poking around a bit, we discovered two posts from co-founder Jon Mayfield over on this Zwift Runners Facebook thread which shine a little light on the problem:

Interesting! Jon’s description of the bug certainly explains the recent uptick in complaints, and it also explains why even high-powered hardware users are experiencing problems.

It also explains why we saw the problem after participating in a large TdZ event recently, and it persisted in free rides afterward. Only a reboot returned our Windows gaming PC to typical performance.

Get the Update

Our sources in Zwift tell us the patch release should happen today or tomorrow, so be sure to check for Zwift updates when you boot up. Not sure how to check if your Zwift version is current? See this post.

About The Author

Eric Schlange

Eric runs Zwift Insider in his spare time when he isn't on the bike or managing various business interests. He lives in Northern California with his beautiful wife, two kids and dog. Follow on Strava

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Mick Such
Mick Such
6 days ago

Great news Eric.

Keep up the good work.

Bruce Joseph Steele
Bruce Joseph Steele
6 days ago

Love Zwift Insider. I look at it almost every day. I Zwifted 260 days last year and it is helping me stay connected with guys I used to race with IRL, and also fit and sane during this weird time. Remember Dr. Hunter S. Thompson’s paraphrased observation, “When the going gets weird, the wired turn pro!”

JayDee
JayDee
6 days ago

As I said. It’s not a HW problem when cpu utilization is low and gpu utilization is non-existent, even though you run Zwift on a potato and normally have higher cpu utilization and gpu utilization at 100 %.

Hugh
Hugh
5 days ago
Reply to  JayDee

I agree with this. I did an 8000 people event on an old MacBook 2015 with integrated graphic @1080p and it was running fine. Other with recent “gaming” machines were complaining. It seems like people forget that what they are running is just a client that renders 100 closest riders. So if there are 100 or 8000 riders it’s the same load on your computer. But on the server-side, that’s way more data points to manage. If a shard in their cluster has a problem, then those riders might be affected as their client don’t receive the data. If there… Read more »

Mattia
Mattia (@matthewmattia)
5 days ago
Reply to  JayDee

Exactly, I have a GTX 1060 GPU and it’s used only around 30% whether it’s going at 60 FPS (normally riding around) or 20/30 FPS (riding in a group). Also the CPU never goes above 50%…

JayDee
JayDee
4 days ago
Reply to  Eric Schlange

That is true Erik, but I don’t really see a reason why Zwift shouldn’t use at least 2 threads and I think that developers could relatively easily find how to use at least 3 threads efficiently. That is bad design at the beginning that the app is single threaded.
Gpu works in a completely different manner and is always able to work at 100 % regardless of application if it is given enough work.

Hugh
Hugh
21 hours ago
Reply to  Eric Schlange

Just did the test and the process was going above 100% (>200%) of CPU usage, so it’s not single threaded.

A zwifter
A zwifter
6 days ago

Do you know if anything else might be in this update? Or just the bug fix.

Jimmie Richey
Jimmie Richey
6 days ago

I am so happy to read this. Not the fix but the recognition that there is a problem with Zwift, and not because I’m down on Zwift but, because I was wondering what was wrong with my system! I run Zwift on a gaming PC I bought just for Zwift. Use a gaming monitor have Cat 6 cable to my router and have fiber internet. In the past week I have had failures I never experienced. For example, I logged in to Zwift to lead my weekly #slowtwitchindoors Hilly Vanilli ride and I was the only one there, I logged… Read more »

Ole
Ole
6 days ago
Reply to  Jimmie Richey

It does not seem like the problems you are describing are related to the bug fix Jon Mayfield is describing. He describes a bug that is triggered by _many users_ in the same event with either a “potato” machine or a random machine and bad luck. I guess none of the Hilli Vanilli ride or the PRL ride had the number of riders as seen in the TDZ rides.

Bracken
Bracken (@bracken)
5 days ago
Reply to  Ole

Based on the description of the bug in the article, participation in an event with enough users would trigger the bug, which would continue to cause problems on other rides, until a reboot. So perhaps Jimmie rode in a TdZ event some time before the other rides he describes.

Ole
Ole
5 days ago
Reply to  Bracken

Yeah, I really hope you are right and that this bug fix fixes the issues he describes.

Scott 12345
Scott 12345
5 days ago
Reply to  Jimmie Richey

Hi Jimmie – The same (yet possibly unrelated to the bug Eric is writing about) issue hit me Sunday (Jan10). 1Gpbs internet working fine on the same PC, it’s a suped up, brand new gaming PC, and I’d try to go to meetups, or any random world, and be the only one there. I rebooted the PC, reinstalled zwift, reset routers and modems, all of it – still all alone. I could see sprint/route jersey times and rider names but no graphics. Really weird is that my wife’s account logged into the PC had no issues. I even tried logging… Read more »

Scott 12345
Scott 12345
5 days ago
Reply to  Scott 12345

PS – Zwift Tech support must actively monitor this page because after 4 days of silence I just heard back on my ticket, about 5 minutes (literally) after I posted here. And guess what they said…it’s my fault for having a potato PC with no internet. See above: brand new PC (i7/GTX1660super) with hard wired internet that gave me a 900mbps speed test result while having the issue. Happy to see a bug fix of some sort coming to Zwift, but in my case I wish they’d try a litter harder in their support responses.

Simon
Simon
6 days ago

I wonder when or if Zwift will switch to a cloud model (like Google Stadia) so hardware stops being an issue?

Fossegrimen
Fossegrimen
6 days ago
Reply to  Simon

Zwift allready runs on aws afaik

Colin Peerman
Colin Peerman
5 days ago
Reply to  Fossegrimen

you misunderstand what Google Stadia is. Google Stadia renders the graphcs for you and delivers them to your device, it’s like having a RTX3090 machine in the cloud, and you can play on a chromebook (almost no cpu/gpu)

Jan Dvořák
Jan Dvořák
5 days ago
Reply to  Simon

HW stops being an issue, but you add a much higher constraint in form of a very fast and stable internet connection. Plus you get compressed video…

John D
5 days ago
Reply to  Simon

One big issue here is the fact that Zwift depends 100% on other devices than the one running Zwift. Adding the latency of your internet connection so Zwift can receive and process data from your powermeter/cadence/powermeter (other devices to come..) and more importantly adding latency in the transmission of incline variation so that your trainer can simulate it; I’m not sure it’s a good idea… On Watopia short climbs like in Titans Grove, it could mean that your trainer will only receive the incline update to add x% when at the screen your avatar will actually already be on the… Read more »

JayDee
JayDee
4 days ago
Reply to  John D

That would be a non-issue for sure. You get sampling from sensors at 1 second intervals, which is more than 10 times what the ping to the Zwift server should ideally be. The latency for gradient changes would probably increase by less than 100 ms, which is irrelevant for this use. That is if it’s actually being sent from the server in the first place.

Trekjocky
Trekjocky (@trekjocky)
6 days ago

So we go from belittling people on inexpensive bikes to belittling people on inexpensive computers riding bikes. Is it now an outside “Fred” without the full kit and wearing underwear turns into an iFred without the wizbang rig that can see the rain or a bear more clearly? Take away all the superfluous graphics waste such as the rain and birds and dolphins that have no affect on my usage or fitness levels.

rdcyclist (Mark Crane)
rdcyclist (Mark Crane) (@rdcyclist)
5 days ago
Reply to  Trekjocky

My brother Fred, who scoffs at all this Zwift shit, will find the post NON-amusing… 😂

The iFred one especially!

Trekjocky
Trekjocky (@trekjocky)
5 days ago

I for one have always felt for the Fred’s, Karen’s, and Pat’s of the world that have been surreptitiously labeled by lazy labelers. Apologies to your brother if iFred becomes a trend but at least it wasnt lazy.

Mark C
Mark C (@rdcyclist)
5 days ago
Reply to  Trekjocky

Oh no, you don’t need to apologize for the “iFred”. I hope it becomes a label. Years ago, there was a column in the humor part of the local newspaper about “Freds” and how they’re labeled the clueless dude in ads and so on. For some reason my brother didn’t find it funny. He’s a serious cyclist and has to hear about being a Fred even though the label is completely inaccurate in his case. But he is an iFred…

John Dunn
John Dunn
3 days ago
Reply to  Trekjocky

iFred I love it!

Gil_SantaMaria
Gil_SantaMaria
5 days ago

Zwift is one of the few platforms that runs on old OS and low performance computers. Blessed be Zwift

Brenton
Brenton
5 days ago

I experienced frame rate drop outs and choppy graphics yesterday in a race event of 262 with only 70 riders in my category. For reference, I run Zwift on a high-powered desktop computer with the latest GPU.

Carolyn Audilet
Carolyn Audilet (@caudilet)
5 days ago

Jon’s comment suggests we “swipe-kill the app on iOS”. Is this also necessary for other systems? I am running on MacOS, similar but not. If I do need to “swipe-kill”, any ideas on how? As always, thanks for all of your help!

Joanna Rhodes
Joanna Rhodes
5 days ago

Very welcome news! However I spent nearly an hour of my life I will never get back trying to persuade Zwift I knew it was their end based on the fact we run high end hardware on two identical turbos simultaneously and clearly on the same internet connection but it was pot luck which device achieved a persistent connection on a TdZ ride. Got fed up of being told I must be riding a potato! Maybe an apology from Zwift to everyone who tried to raise a ticket only to be fobbed off and hardware shamed?

BikePower
Super Member
BikePower (@bikepower)
5 days ago

I still remember the Zwiftcast podcast when they told listeners who were experiencing problems that the cause of the problems was their “potato” computers (when in actuality it was a bug that Zwift was aware of). That was the point when I stopped paying attention to “technical advice” from the Zwiftcast.

Joanna Rhodes
Joanna Rhodes
5 days ago
Reply to  BikePower

Me to the tech support chat “are you aware of the difficulties users are experiencing in TdZ rides?”

Tech support chat replies “me personally, no I’m not”

Me to tech support “do you need me to describe the issues?”

Tech support chat “you are probably riding a potato in a field with no internet”

Ben Pitt
Ben Pitt (@benjamin_pitt)
5 days ago
Reply to  BikePower

Well to be fair, the people with the issues were running potatoes, and a better system didn’t have the issues. But yes, it’s great to see Zwift has found a bug that is causing these weird issues.

Jan Dvořák
Jan Dvořák
5 days ago
Reply to  Ben Pitt

It doesn’t matter whether you use the latest and most powerful HW possible or 5+ years old potato when the SW is garbage.

Joanna Rhodes
Joanna Rhodes
5 days ago
Reply to  Ben Pitt

That’s not actually the case Ben, Zwift has acknowledged this because people NOT riding potatoes are experiencing it too.

Allen Day
Allen Day
5 days ago

Interesting how the tune has changed. I’m glad to hear after more than two years of this they are finally going to stop pointing the finger back at every user, even the savvy ones and one with exceptional hardware and bandwidth and fix the problem. Hopefully they can leverage what they have.learned for the future, about optimizations and about trending customer service complaints. It was never the potatoes.

Mholden
Mholden (@holdenadventures)
5 days ago

Will be sad to lose these game elements. Part of the charm of Zwift 🤣
I think they should bring it back as an April fools day event in a couple of years! All bikes and no riders! Or reverse 🤣

rdcyclist (Mark Crane)
rdcyclist (Mark Crane) (@rdcyclist)
5 days ago
Reply to  Mholden

Exactly Mari! If Zwift fixes all of these eff-ups we’re going to lose the element of surprise we have every time we ride! It’ll be such a sanitized experience AND what will we have to complain about on these forums. I’ll probably have to switch over to Rouvy or something to get the uncertainty we cherish here…

Steve Newell
Steve Newell
5 days ago

I’ve only been using Zwift since 30th December 2020, but have used it every day. This bug has hit 2 of my 14 rides. At least, I hope it’s this bug, because if Zwift is usually this unstable, then I probably won’t continue using it. I’ve been a computer programmer for more than 30 years. I tried everything I knew to rescue my rides, but couldn’t manage it. It seems to me that something causes the Zwift client software that runs on your computer to go into an unintended infinite loop and consequently consumes as much CPU as your computer… Read more »

Razz
Razz
4 days ago

Well, let’s make it clear. Swift graphics is really poor.
And it runs very slow on my old notebook, which can run many games (up to 2012 year) with much more details and effects …

Squbel
Squbel
4 days ago

Got the update today (around 1600 NZST). Not sure if it’s the patch or the fact that I have also moved from laptop (gtx965m) to PC with GeForce 970gtx but I just had solid 60fps during 10min test on Ultra settings. Previously this was around 30fps on High setting. I think there is a massive difference 👍

Jerry Anderson Sr
Jerry Anderson Sr
4 days ago

I just made a complaint Wednesday about this same problem to zwift. This been happening off and on for a while. I hope they can really solve this problem for good.

Simon Collins
Simon Collins
4 days ago

So pleased to hear this has finally been admitted by Zwift. I had so many issues with season 1 ZRL. I wrote to Zwift and was told this was because I had Zwift running on another device!!

Matt
Matt
3 days ago

I had this issue just doing a workout on my own using a computer that was only a few years old. However the issue always occurred when there were more than 30,000 riders on the system. After a couple of crashes I just decided to using ZwiftPrefs and riding in a different world and had no issues. However, I am glad that this issue is finally being fixed!

Toni
Toni
2 days ago

Any rumors of a new course or new tarmac in Watopia???

JoBar
JoBar
1 day ago

Updated on my ipad with the latest release. Did twice Stage 3 of the tour both crashed at the same point when just crossing the finish line. So still something there which is not right.

Erlendur
Erlendur
6 hours ago

“low-powered “potato” users” — exactly how much potato are people using? I use an old gaming PC as my Zwift computer. It was top-of-the-line stuff but 10 years ago; Intel i3 quad-core, 4 GB RAM, NVIDIA GeForce GTS 450 with 1 GB VRAM with the latest available drive from March 2018. Never have any problems. Does Zwift publish OS, hardware, GFX stats?

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