Frame rate drops unless I have Firefox open!

[Modeler]

This is one of the weirdest glitches I've ever come across. I'm running CCS64 v3.5 on Windows XP SP3, it's a Core-2 Duo and the CPU doesn't even break a sweat.

If I run CCS on its own, leave at at the blue screen and look at the speedometer, I get an 88 - 90% frame rate at around 44 FPS even though the CPU is about 1% busy. Now here's the thing - if I open Firefox in the background and leave it on a page that has flash on it (or even the default iGoogle home page) I get 100% / 50 FPS!!!

As soon as I close Firefox it drops again. It seems to do the same with other applications, for instance I get 100% if I also have MAME running in the background. I've never seen an emulator perform worse when there is no load on the CPU. It's not a problem, just seems odd to have to make sure I have something chewing lightly on the processor. The extra load is minimal but it seems to kick CCS into action, interestingly CCS itself doesn't take any more CPU than it had before.

Very weird!

[Modeler]

Must just be me then, although I've observed this on more than one computer.

Here's a video of what happens (sorry about the poor quality):

http://uk.youtube.com/watch?v=YeG4jkkfA5A

You can see that the emulator runs at 100%, then when I close Firefox it drops to 88-91% and starts stuttering. As soon as I open Firefox again it works fine!

[Stuart Toomer]

Perhaps it is some weird buffering issue?

[robski]

I was having the same problem. I'm using CCS64 v3.5 with XP SP2 on an AMD 3000+ and the speed/frame rate were just as bad (didn't check the CPU load). The sound was also as choppy as, it sounded like it was trying to play all the sound through one channel (sfx caused music to cut in and out). Quite irritating, to say the least!!! I found opening Firefox didn't do much, but having that open as well as a few other folders on my desktop (recycle bin, etc.) seemed to improve things slightly. Go figure!

After much trial and error (mainly in the sound settings), I think I've sorted it. Try setting the video so it's not windowed (320x240 seems to fit the screen pretty well). After changing that, my speed is at 97-100% and frame rate's up to 48-50fps.

I not sure why this fixed the problem, possibly an issue with being displayed in a window as opposed to full screen? The problem also got considerably worse if I started in a window then maximised it.

[robski]

Oh yeah, I forgot to mention I only figured that out a couple of hours ago, as such I've only tested a few games, but it's all good so far.

[Stuart Toomer]

Yes, Windowed Mode is more intensive than Full-Screen Mode in CCS64 - the bigger the window in Windowed Mode, the more load it places on the host CPU. This may be a legacy coding issue. I'll see what Hakan says about it. For now, for high performance, use a Full-Screen Mode in CCS64...

[Håkan Sundell]

Oops, this seems like a quite weird problem. Currently, I really have no precise idea of what is causing it. Surely, I will investige it further in the code, but as I can not repeat the problem on my computer I can not promise a fast solution.

Have you tried changing the Video (Alt+V) Update Mode? Change from Automatic (default) to Frame. Maybe also try to change the Update Freq (50Hz, Screen etc.).

Should also be quite interesting to see what frame rates / speed rates you get if you change the speed (Alt+F3, or Shft+Alt+F3).

What Sound settings (Alt+S) are you using?

[robski]

With the screen set to Window 2x, I tried changing the video settings, as you suggested, but there was no improvement and very little change between settings.

Increasing the speed(Alt+F3) to 200% only made the speed go up to 160-170% at 41-42fps.

After I got it running properly in fullscreen mode, I went back into the sound settings and changed everything back to default.

It's just not happy running in a window it seems, unless there's other stuff running in the background, on my machine anyway.

[Modeler]

Crikey, the man himself speaks... I'm honored!

Please do note that I reported this in the interests of the emulator's development, I'm happy with the work-around. I have exactly the same issue on another machine, the same symptoms apply. The issue affects two of my three PCs.

If it helps, it seems to be the flash player rather than Firefox that fixes it. Opening a flash-enabled page in IE has the same effect. At no point is the CPU getting maxed out, CCS64 only takes around 9% of my CPU when running at full speed. Interestingly, when I close the browser the emulator takes less than 1% as if it is somehow deprecating itself.

If I take it to 5 x speed, I get 500% / 50 FPS with flash and ~400% / 40 FPS without.

Turning off automatic frame skip didn't make any difference to the frame rate, but it does seem to use more CPU.

Sound settings:

Code: Select all

Sound Output - On
Sound Device - Primary Sound Driver
Sample Freq - 44100 Hz
Sample Bits - 16
Oversample - 1 (44100 Hz)

SID Chip - MOS 6581
Filter Emulation - On
Filter Par FGain - 100
Filter Par FBase - 100
Filter Par DGain - 100
Filter Par DBase - 100

HardSID - Off
Mix Mode -

Sound Sampling - Off

[Timiditas]

I noticed the exactly same issue on another system, with another software.
A game called "Moorhuhn Winter" shows weird tearing while scrolling the screen from left to right and vice versa.
Strange framerate drops, that is. This is no real vsynch issue but vsynch seems to be involved in this.
When I have a flash video running in the background, the tearing is gone.

Try different default refresh rates for your display, I had some luck with that for CCS.
Why a flash video fixes this, I can't say or even guess. This is really strange.
I BET this is not a fault in CCS but it is a system issue.

Please post your system specs and dxdiag report.
I will try to get my hands on the system again, where I witnessed that issue. I only remember that it had an old ATI GPU and the OS was Windows XP on SP2.