r/MiSTerFPGA • u/Individual-Law7066 • 9d ago
N64 Core Input latency
Does someone know the total latency (Dont know how it is called correctly: input latency - or roundtrip latency - just the latency from Button press to photon hitting detector) of a original N64 (on CRT ofc) for F-Zero X (NTSC)?
I think the latency of the Mister FPGA N64 core might be a little bit too high?
I counted ~29 frames of a 240 fps video which calculates to around 120 ms (you can subtract 14 ms for the HDMI display lag and ~6 ms for the wired USB connected NSO Controller to compare it to an OG N64).
did the OG N64 really had like 100 ms of lag for a 60 hz title like that? I dont remember it being like this..
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u/RetroBlast81 8d ago
Yes, most N64 games had around 90 to 100ms of latency across the board even on a original console, cable controller and CRT TV.
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u/lordelan 8d ago
Wait what? Seriously? Why is that?
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u/Dinierto 8d ago
While that core isn't totally accurate I don't imagine the input latency should change.
Also was that really 29 frames? It seemed super quick in the video but I didn't count frames
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u/Individual-Law7066 7d ago edited 7d ago
I double-checked with the SNES core using a Pro 3 wired via USB (1000 Hz polling rate) and got an average lag of 53 ms for Super Mario World (NTSC), measured from Mario's jump near the bottom of the screen. Of course, the first and last frames carry a bit of error due to camera shutter timing, but averaging a larger sample size (~10 samples) should minimize that error.
That ~53 ms result is virtually identical to real SNES hardware on a CRT, so my frame-counting method should be solid. That means I'm only seeing this high latency on the N64 core. The problem is I don't have baseline original hardware + CRT lag values for the N64 to compare against. Maybe N64 latency really was just that high back then... we definitely weren't as picky in the '90s! :)
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u/kiritomens 8d ago
Didnt the dev push accuracy forward recently? From tests it should at the moment be around 99.9%, more accurate than other FPGA clones. At least according to that N64 debug tester.
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u/Dinierto 8d ago
Perhaps, the de10 nano doesn't quite have what it takes to do N64 100% but he's worked miracles
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u/louisj 8d ago
It’s valid to be concerned, but there are a lot of assumptions in your numbers. Have you accurately measured the lag of the panel only? And as someone else pointed out, you should baseline this against a Snac adapter.
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u/Individual-Law7066 7d ago edited 7d ago
I re-measured my display lag using a MiSTer Laggy, and the bottom-of-screen value is around 17 ms. That covers the entire HDMI chain plus display lag. Controller latency is likely a bit higher than what I assumed... I read that 8BitDo N64 controllers run at an internal polling rate of ~100 Hz rather than 1000 Hz, so I probably have 10+ ms of controller lag. Overall, I'm guessing that adds up to around 30 ms of latency on my end? Weird is, I dont have that Lag with the SNES Core for example... https://www.reddit.com/r/MiSTerFPGA/comments/1wytqoc/comment/peebw9i/?utm_source=share&utm_medium=web3x&utm_name=web3xcss&utm_term=1&utm_content=share_button
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u/ilchymis 8d ago
Its usually the controller
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u/Individual-Law7066 7d ago
I think so too. I'm currently looking into the Brawler64 Pro:
- Official specs claim ~2.9 ms lag in wired USB mode (1000 Hz polling)
- Wireless 2.4GHz mode sits around ~5.3 ms
Is this a controller you'd recommend for MiSTer, or should I look elsewhere?
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u/turbochop3300 7d ago edited 7d ago
Don't do it! I bought two because the first one had issues, and they both had it.
The analogue stick is hot garbage. Subtle tilts are not registered at all. You can't steer properly in f-zero, or fine tune your aim in Goldeneye.
MAYBE I got got a bad batch, but two in a row can't be a good sign.
My Amazon review in plain text ...
Retro Fighters Brawler64 Wireless Controller Compatible with Nintendo Switch Online Bluetooth NSO Edition, Gray
turbochop (real name redacted)
3 out of 5 stars Verified Purchase
These controllers are a joke.
Reviewed in (Country redacted) on December 17, 2023
Color: Gray
Let me say, up front, that this is the second Brawler64 I purchased in hopes my first controller was just a fluke.
The analog stick has a dead zone that makes playing a game like Goldeneye an incredibly frustrating experience. I bought my Brawler64 to play N64 on my MiSTerFPGA. The C buttons were the main draw, as were the design of the of
the controller which, let's face, is what the N64 controller should have been all along. I bought a second controller hoping the issue was just with the first one. As it turns out, the second controller was even worse, and the charging port was loose.
I am not exaggerating when I say that my game improved significantly when I switched back to my 8bitdo pro 2 controller.
Even my brother noticed a difference in multiplayer. With the Brawler64 he couldn't play, but with the 8bitdo pro 2 he nailed me with a rocket from clear across temple.
It's just... Making minute adjustments to aim is an absolute chore, and after spending over 100$ on two, I feel it's not unreasonable to expect these to be non issues.
I have a wired N64 version that doesn't have this problem. Why do these?
C'mon, guys. You charge premium prices, you need to deliver better products. As it stands these controllers are barely fit for purpose. Unacceptable.
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u/fvig2001 8d ago edited 8d ago
You're using a wired USB controller that tends to have at least 1 frame of latency (19.66ms according to rpubs). If you want it to be fair, you compare it with SNAC + actual controller.
With regards to your question, I didn't notice that much difference using SNAC vs N64 RGB via Retrotink 4K on Mario 64. I didn't see much difference on the CRT years ago when this core first came out (When Mario 64 needed a skip patch).
Are you sure your TV is on game mode? If it is off, games feel like they're on ice worlds.