LCD and smooth scrolling (not a 50Hz or a vsync problem)

[aidenn]

Hello,

I'm having a problem getting silky-smooth scrolling with... well, anything that does Hz-synced emulation.

This is not a problem with Amiga emulation, but rather with emulation in general (old consoles, computers etc.). Nor is this a problem with getting 50Hz to work on a LCD monitor . And I'm asking here, because it's the most noticeable in WinUAE (since smooth scrolling was one of the most fantastic things about Amiga games) and I know that community here is quite knowledgeable.

Anyway, I've no problem with vsyncing my monitor to 50 or 60Hz. It's one of those rare LCDs that can do 50Hz natively - NEC 1980FXi, 5:4 ratio, fantastic colours (S-IPS) and response. Should be an emulation paradise. The problem is that even when I sync to 60Hz and play a NTSC game (or 50Hz and play a PAL game, it doesn't matter), be it in WinUAE, all the SNES emulators, Genesis and so on, I can't get smooth scrolling. It's not tearing or anything (so vsync works correctly), but, while scrolling, every second or so I get a microscopic jerk. It's very hard to notice, but it's there, constantly jerking at the set interval (can't tell you the exact timing, but it seems to be about one second). Triple buffering doesn't help either. I don't remember getting that with my old CRT and a P4, so it must have something to do with the monitor or my rig, which goes as follows:

C2D 2,8 GHz
4 GB RAM
GTX 260

Any ideas?

[meega]

Use real hardware instead of emulating it.

[aidenn]

Originally Posted by meega

Use real hardware instead of emulating it.

I had them at one time or another (Amiga 600 and a NES at least). Maybe someday I'll consider making a retro-gaming room when I get a bigger house, but for now emulation is all I get. And it should work, it's not a problem with emulation per se, since it worked on my old PC. Something odd is going on with my monitor or my graphic card or some settings somewhere and I'd like to know what it is.

[meega]

People are unreliable witnesses. That is not conjecture, it is fact. Research has been done, and it is evident that people remember wrongly. You might think you had no problems before, and you might in truth be correct, but it is quite possible that you are remembering wrongly.

Try the real version of whatever you are emulating - beg/borrow (do not steal) something from someone, and try that. If the problem remains then it's the monitor that needs to be examined (somehow).

If the problem goes away then you will know rather than merely believe that it's good for the purpose. Then you can concentrate on sorting the emulation out.

[aidenn]

Originally Posted by meega

People are unreliable witnesses. That is not conjecture, it is fact. Research has been done, and it is evident that people remember wrongly. You might think you had no problems before, and you might in truth be correct, but it is quite possible that you are remembering wrongly.

That's true, I might've remembered wrongly, but only that it was working fine on my P4. It was a slow system overall and I might've developed a perception filter to push all imperfections deep inside my subconscious.

Originally Posted by meega

Try the real version of whatever you are emulating - beg/borrow (do not steal) something from someone, and try that. If the problem remains then it's the monitor that needs to be examined (somehow).

Actually, that shouldn't be necessary, because smooth scrolling is something that's common knowledge to Amiga or 16-bit console users and everyone that used the real thing knows that smooth means smooth. Of course, not every game was smooth, but most of them (and especially the demoscene prods) were.

And I can't get anything to scroll smoothly, not one demo, not one game.

Originally Posted by meega

If the problem goes away then you will know rather than merely believe that it's good for the purpose. Then you can concentrate on sorting the emulation out.

I suppose I could do that, but... that monitor is all I have. No TV, no nothing. Anyway, really, it's not a question of remembering, unless you want to question the very existence of smooth scrolling.

[meega]

I have a 1.7GHz P4, 1GB RAM, 32MB Nvidia graphics card, and a 17" Iiyama CRT (a good one). I have tried WinUAE. It is grossly unsatisfactory at scrolling.

If I want the Amiga experience, I boot my A1200.


Ed: Note - I am not criticising WinUAE - it's my experience of the emulation in my system.

[aidenn]

well, 1,7GHz in P4 terms is like 1,2GHz in P3 terms, which means it isn't really enough for smooth WinUAE scrolling. It should eat 100% of your CPU and that's where your jerkiness comes from. WinUAE needs a lot of processing power and its doubly true for the newer releases which really need a dual core (not that they need two cores, it's just that the C2D architecture, even in a single core, is vastly superior to P4's).

Anyway, my issue is not that the scrolling is "grossly unsatisfactory", it's great, constant 50/60fps, no twitching at all... except for that one jerk. At first I thought it was because the game was running at 59.94Hz, which isn't exactly 60Hz. I pondered that for a bit, but then I tested PAL games, which run at exactly 50Hz (with the monitor set to 50Hz too, of course) and the issue remains the same. Anyway, the difference of 0.06Hz shouldn't be noticeable with the naked eye.

[meega]

Originally Posted by aidenn

It should eat 100% of your CPU

It doesn't.

Some people might be entirely happy, to me it's not good enough in some regards. If scrolling isn't relevant then WinUAE has some undeniable advantages, configurability, available or possible resources, huge power, etc. But it doesn't play pinball properly.

[aidenn]

Originally Posted by meega

It doesn't.

Really? It should. Weird. It would on my P4 2,4 GHz, unless I sacrificed some audio quality. And even then it was very high.

But maybe we're talking about different releases. I remember playing with the old DOS version of UAE on a 486 and it was "fine".

Anyway, it's not really a WinUAE problem. for example, ZSNES, Snes9x and bsnes all manifest the very same issue. And I've seen recordings (full 59.94fps captures, not the youtube crap) that don't. See tasvideos.org, it's full of them (and all are made with an emulator, since that's the whole point of a tool-assisted speedrun).

By the way, I tried to make a custom resolution with the nVidia control panel. Set it to 59.94 Hz and nada - still the same issue. I'm surprised that it worked though. That's one nice LCD I have. I wonder if the jerkiness is its fault... though it shouldn't, because when I watch 59.94 fps videos - they scroll smoothly. Although maybe it's the video player automatically compensating or something.

[meega]

Here, I'll politely ask you how old you are. You are currently trying to tell a 43-year-old who has 20 years experience of owning and using Amigas and 35 years experience of using computers in general what *should* happen on a system about which you know nothing other than what I have posted in this thread...

Again, I suggest that you try using the real hardware with your monitor. If the problem remains with the genuine article, then maybe your monitor can't do what you want it to do.

[prowler]

Originally Posted by aidenn

That's one nice LCD I have. I wonder if the jerkiness is its fault...

Hi aidenn,

For more info on LCD monitors and smooth scrolling with real hardware and WinUAE see this thread:
LCD monitor with 50 Hz pal games

[aidenn]

Originally Posted by meega

Here, I'll politely ask you how old you are. You are currently trying to tell a 43-year-old who has 20 years experience of owning and using Amigas and 35 years experience of using computers in general what *should* happen on a system about which you know nothing other than what I have posted in this thread...

I'm 26. Anyway, it really should. I mean, if I, who have a bit faster P4 than you, had speed troubles with WinUAE (IIRC, it was about the 1.6 release), then so should you. Though that was on highest compatibility settings and low audio latency as I hardly consider anything that has high latency or sub-optimal audio/video quality and/or compatibility a comfortable solution.

And then I though that about 1.0 release and earlier it all ran smoothly even with 450 MHz. So it just sounded plausible that we were talking about different releases, that's all.

Originally Posted by meega

Again, I suggest that you try using the real hardware with your monitor. If the problem remains with the genuine article, then maybe your monitor can't do what you want it to do.

Oh, that's what you meant. I'll try, though I don't know anyone around with an Amiga.

prowler, hello. I read that post before. It's about a different issue.

[cosmicfrog]

aiden your not comparing like with like meega might not have anything else in running in backgound or no drivers installed or what ever

how is that thread for a different use/issue ??

so whats it like at double. 100Hz or 120Hz ?

[aidenn]

Originally Posted by cosmicfrog

aiden your not comparing like with like meega might not have anything else in running in backgound or no drivers installed or what ever

I can't quite put that sentence together, but if you're wondering if my P4 2,4 was having background apps or something contributing to the speed problems with WinUAE - no, it wasn't. I'm a performance geek, I always tweak apps, strip them of unnecessary features and so on. That includes the OS.

Anyway, as I said, it was with highest compatibility settings and so on. If I turned the audio down a bit it was fine.

Oh, by the way, I've checked WinUAE on my P4 1,5 GHz at my parents' home (I exchanged my 2,4 for 1,5 after getting a C2D and left it in another city). Well, best compatibility settings were out of the question, but after tweaking things a bit I managed to get perfect scrolling in a few A500 demos and games (that's with a CRT, naturally).

So, with that (that is, settings or innate WinUAE inability of producing perfect scrolling or perception problems on my side) out of the question, it leaves either the monitor or the graphics card. I'm in a process of procuring someone with a real Amiga, but so far I've had no luck. If nothing comes up, I'll take the LCD to the P4, though that's a 100km train ride with a monitor that weights a tonne (it must be the heaviest LCD ever made).

Originally Posted by cosmicfrog

how is that thread for a different use/issue ??

That thread is about finding a suitable LCD monitor for playing PAL games. My monitor can display 50 Hz without problems. Specs-wise there shouldn't be any problem, so I want to troubleshoot further.

Also - since it happens in NTSC and 60 Hz too (which is the standard and the default mode of this monitor), and with anything besides native scrolling, not just WinUAE - it must be something entirely different.

Well, I'd suspect the monitor from the get go, but I've read that certain nVidia cards have trouble with this kind of emulation and Hz-syncing. Anyway, I'll just have to test one of them somehow, but it's kinda hard atm, I live in a godforsaken place with no one to turn to, so I though I'll ask, maybe someone here had the same issue or knows what's going on.

Originally Posted by cosmicfrog

so whats it like at double. 100Hz or 120Hz ?

This monitor can't do 100 or 120 Hz, 50-75 only. also, 100/120 Hz for emulation is quite rubbish, because most of the so called 100/120 Hz screens can't really do 100/120 Hz, not to mention they're mostly TN screens and that's completely out of the question if one cares about quality.

[cosmicfrog]

from what I gather lcd`s have problems doing smooth scrolling, anyway good luck

[meega]

http://www.tomshardware.com/reviews/...n,1233-15.html

NEC 1980Fxi: The Other Side Of The Coin
NEC has optimized their product for photography and pro image processing. And unfortunately, that's all the monitor can do well.
...
You can see clearly that the 1980Fxi is slow. Its latency readings peaked at 33 ms, and in the best case it logged 18 ms. So obviously, this monitor can't be recommended for playing recent computer games.

http://www.tomshardware.com/reviews/...n,1233-16.html

But forget about gaming, given the obvious latency drawbacks. This is a serious monitor, and games aren't what it's intended for.

[Retro-Nerd]

18-33ms response time? The motion blur must be awful with scrolling games.

[aidenn]

What latency has to do with my problem? Yes, I see a bit of smudging @ 60 fps, but that doesn't change the fact that native PC scrolling is smooth. Let's even drop the 50 Hz (on the assumption that maybe my monitor's 50 Hz is incorrect) out of the equation and concentrate on 60 Hz.

Anyway, I've google high and low and found out that some people with PC multimedia centers and videos @ 29.97 fps and 59,94 fps are having the very same issue. And it's not the monitor, but nVidia cards. Anyway, their solution is to override low-level display mode settings like front porch, polarity and so on + fine tune the refresh rate to something like 60.05 or 60.02 Hz. The problem is, their settings are made for different resolutions (which my monitor can't support) and different screens, I'd have to invent my own, but I've no clue on how to even start with it, there's so many possibilities it hurts my head. Though if that's really my issue too, I guess I'll have to move with this discussion elsewhere.

Originally Posted by Retro-Nerd

18-33ms response time? The motion blur must be awful with scrolling games.

It's not that bad, I only see it when I look for it. That hickup I came here with is far more annoying. All in all, I bought this monitor cheap and used because it's a fantastic piece of hardware for graphics design. Playing games on it is secondary.

[Retro-Nerd]

Even on CRTs you notice some "hickups" from time to time with nVidia cards+crappy drivers in emulators, if you look closely. Nothing is perfect.

[cosmicfrog]

creating custom resolutios is`nt to hard
in nivida control panal you can add a custom res, sure theres something similar for ati