Do gaming consoles have pre-emptive multi-tasking OS?

[rcgldr]

Wondering why games written for consoles and ported to PC's often seem to be system senstive where the entire game is affected by system peformance instead of just the graphics, which should be an independent thread / task in a game. In older multi-threaded games written for PC's, the graphics rate could be bogged down and yet have no effect on the games physics, which ususally consisted of one thread to sample controller inputs at some fixed rate, and a physics thread(s) that ran at some fixed rate to do the numerical integration to convert accelerations into velocties and positions of the objects involved, which in turn sent the positional update to the graphic thread. The frame rate in the graphic thread could take a hit on a slower system, but the core physics wasn't affected. In some of the newer games, it seems that the entire game can take a hit if graphics gets behind.

 

[Antiphon]

Xbox uses a stripped down version of Windows 2000, fully multitasking.

 

[rcgldr]

Xbox uses a stripped down version of Windows 2000, fully multitasking.

Thanks. Wondering about the other consoles, since many games are designed to run on multiple consoles (PS3, XBOX, ...) as well as PC's. Those are the games that seem to have issues with the difference in PC performance.

 

[Jocko Homo]

Wondering why games written for consoles and ported to PC's often seem to be system senstive where the entire game is affected by system peformance instead of just the graphics, which should be an independent thread / task in a game. In older multi-threaded games written for PC's, the graphics rate could be bogged down and yet have no effect on the games physics, which ususally consisted of one thread to sample controller inputs at some fixed rate, and a physics thread(s) that ran at some fixed rate to do the numerical integration to convert accelerations into velocties and positions of the objects involved, which in turn sent the positional update to the graphic thread. The frame rate in the graphic thread could take a hit on a slower system, but the core physics wasn't affected. In some of the newer games, it seems that the entire game can take a hit if graphics gets behind.

I'd be shocked and awed if not all home (non-portable) gaming consoles made after the original Playstation had preemptive multi-tasking operating systems. Even the N64's OS had preemptive multi-tasking, even though it wasn't round-robin...

The multi-threaded scheme you describe can only work if the game state is relatively small. After all, the renderer can't render the game state while that very state is being modified, now can it?

 

[rcgldr]

The multi-threaded scheme you describe can only work if the game state is relatively small. After all, the renderer can't render the game state while that very state is being modified, now can it?

I've seen racing games that support up to 42 players online, and the game state is being updated via positional update packets over the internet, and yet the view from each player's screen while slightly different due to lag, looks reasonably close depending on how well the code predicts locations of cars between packet updates, even handling situations where the positional update packets are occasionally lost. If this situation can be dealt with, then messages updates between threads on the same computer should be able to handle a much larger game state.

The complexity of rendering moving objects isn't an issue for the messaging done between the physics and graphics thread, just the information required to update the current position (orientation, velocity, ...) of the moving objects in real time.

What started me thinking about the consoles, is the fact that a few racing games ported from consoles to PC's have had issues with the variance in performance in PC's. The games written for PC's and then ported to consoles didn't seem to have these issues.