CPU Selection can a i3 handle group rides

I been experiencing CPU bottle neck on group rides when disconnected form the internet I get 70-100 FPS in a sparsely populated area of the map I get 30-50FPS and a group ride I get 10-20FPS on 1440 high.

I’ve been looking in to various around the £200-300 bracket and from some staggering results from the smaller i3 CPU’s can anyone back up the performance of the little I3 processors in group rides.

Below are some screen shots from Zwift analyser i chose the GTX1060 and there is loads of logs and it should not be GPU bound at 1080 ultra.



The i3-8100 worked great for me. It would sit around 70% usage on all 4 cores in a group ride scenario.

That said, if I were upgrading my CPU now I’d probably go with the i5-9400F. Super cheap for 6 cores that can boost to 4.1Ghz.

With RTX Nvidia cards out in abundance now and crypto mining dead, there’s also a lot of great deals on GTX 1070’s and the like. So my 2 cents is new CPU’s are great and so are one Gen old Nvidia GPU’s.

Adding, my old 1060 3GB was also a little high on usage at 1080 Ultra Res in group rides, around 85%. This is why I’d go for a 1070 or above.

I have a i5-3470 and the CPU isn’t the bottleneck, it’s my old AMD HD7850.
You should have a Quadcore. i3 in the 8000s is Quad, below (2000-7000) is dualcore.

With a several year old i3, I’ve consistently seen sub-50% usage running Zwift 1080p Ultra plus streaming hi-def video on a second 1080p screen. The GTX 960 is the bottleneck on big group rides, particularly in the dust, or in the starting pen, where frame rate drops for some reason. Otherwise 60 FPS is easy.

I’ve played with using RivaTuner to cap FPS at 30 since it looks fine, the GPU usage remains low in most situations, I don’t care about the visual difference, and it doesn’t affect “game play.”

edit: to specify, my experience is that an Intel Core i3-6100 CPU @ 3.70GHz is plenty of CPU to run Zwift at Ultra 1080p plus a second 1080p stream at the same time.

Thanks for the reply I have a i5-4690k in the house I tried my rx570 in and it was poor. I even tried a clean install of windows 10 and got 10 fps in the pen and averaged 20fps. It picked up to 30 -50fps as the group split up.
Slightly better than my phenom cpu

Thanks for the reply I’d be more than happy with a minimum of 30fps and a average of 50fps. The more I dig the more I wish I’d bought a nvidia gpu

Yes. Also look at Pentium G4560 and G3258 dual cores performing well with 9xx and 10xx Nvidia CPUs. A Geekbench 4 single core score of 4000 is a good baseline for whether or not the CPU will bottleneck a modern GPU. For example, https://browser.geekbench.com/v4/cpu/search?q=G4560

With your rx570 and phenom II, shadows might be killing performance because of those lame AMD OpenGL drivers (I read there’s literally nobody there anymore who knows how any of that code works, so no one dares touch it). Have you tried editing your configs\high.txt to turn down shadow resolution and turn on simple reflections?

set gSimpleReflections=1
sres 512x512

or even
sres 256x256

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i’ve tried 720 with medium detail up to 1440 with the ultra config copied into the high with sres 2048x2048 on a group ride the no noticeable difference in fps maybe it goes from 12 to 15 FPS. if I disconnect from the internet it runs between 60+120 fps reconnect and it drops back to 10-20FPS.

I see what you mean now. I have an older Xeon 5672 CPU (4 core, 8 threads) with an AMD Radeon 7870 1GB and if I disconnect from the internet the FPS goes from 40 up to to 60. I reconnect and it drops back down to 40 as soon as the rider list reappears. Every time. When the rider list came back, there was never more than 4 or 5 other riders nearby to render, so it is definitely not the overhead of having to draw the other riders. I was just stationary at the side of the road. There does not appear to be any difference in CPU load with or without networking, so I have no idea why it blocks the rendering, but obviously it does. Maybe it’s the overhead of trying to figure out everybody else’s position in time for the next render. When I put an Nvidia GTX 960 2GB in the exact same machine, it holds a solid 60 fps. I can’t explain it. My guess is maybe Nvidia’s physx helps out with the positional calculations ¯_(ツ)_/¯

Also, zwiftalizer looks like it needs an update to better report those deliberate networking disconnects. They appear as network delays, when they should really be errors.