Zsnes Priority

Kriegan · Post by **Kriegan** » Sat Jan 22, 2005 10:11 pm

I've been keeping up with the betas up to the current release. But since 1.40 was released, It seemed like there was a performance hit. I thought it might change in 1.41, it didn't. It still hasn't in 1.42.

I use XP pro. A nifty feature of pro, is when you hit ctrl-alt-del and brings up the task manager, you can pick and choose the CPU priority of whatever program you wish. So I got to looking one day, I saw that Zsnes was set on the lowest priority by default. When I moved it to "normal", the lag dissapeared, which is what I expected. I don't know much about programing, but is there a setting within Zsnes that tells the OS what priority the program should have? It's a simple task for me to fix this, but regular XP users don't have a choice.

Post by **Agozer** » Sat Jan 22, 2005 10:43 pm

Well, you can set ZSNES to run in High Priority mode from the Options dialog, but I wouldn't recommend this.

Kriegan · Post by **Kriegan** » Sat Jan 22, 2005 10:50 pm

I know that, but it doesn't make sense for it not to run at regular priority.

Kriegan · Post by **Kriegan** » Sat Jan 22, 2005 11:06 pm

Ok, I did more testing. Even when I set Zsnes 1.42's priority to normal, or above normal.... it FORCES itself back down to Low. What's that all about? I discovered this after playing for a few minutes. Everything would be smooth and after I saved or loaded from a savestate, it would return to low priority. I tested it quite a few times. Same results. I think this is a serious bug. Someone on a newer system wouldn't even be phased, but people on a 1ghz, or less, could. 0.o

ThunderClaw · Post by **ThunderClaw** » Sat Jan 22, 2005 11:40 pm

800 Mhz P3, GeForce 4 Ti4200, WinXP Pro, 256MB RAM.

I cannot duplicate your bug report. ZSNES starts at Normal priority and stays there. Putting it down to Low makes it stay at Low.

Post by **grinvader** » Sun Jan 23, 2005 1:45 am

If you have other cpu-eating processes, ZSNES might be pushed down as it's not very cpu intensive when running a rom, unless you're using hq4x.

Deathlike2 · Post by **Deathlike2** » Sun Jan 23, 2005 2:24 am

To reproduce the "bug", just load up ZSNES (just the GUI, it doesn't matter if a ROM is loaded)... the priority set is Low. When a ROM is loaded (and you are not in the GUI), this changes to Normal.

This is what I think the original poster is somewhat confused about (although, I'm not sure the low priority is intended when only the GUI is loaded).

I don't know what OS the poster is using, this is reproducable in Win2k in any case.

I'm not sure what this "lag" is... if it's GUI lag, this might explain it, but if the emulation is laggy, that would be a different story.

adventure_of_link · Post by **adventure_of_link** » Sun Jan 23, 2005 2:44 am

Deathlike2 wrote:I don't know what OS the poster is using, this is reproducable in Win2k in any case.

Kriegan wrote:I use XP pro.

stale · Post by **stale** » Sun Jan 23, 2005 3:03 am

it seems to me that something (either zsnes or windows) senses if zsnes is in focus, and it lowers its priority if it is not. I can catch it in either state on my pc, if I'm really sneaky.

Deathlike2 · Post by **Deathlike2** » Sun Jan 23, 2005 8:44 am

lol, I apparently didn't read thoroughly

it seems to me that something (either zsnes or windows) senses if zsnes is in focus, and it lowers its priority if it is not.

It's ZSNES, not Windows... ZSNES changes it's priorities depending what state it is in. Windows does not factor into it...

Kagerato · Post by **Kagerato** » Sun Jan 23, 2005 4:40 pm

I wouldn't say that with such certainty. The NT kernel makes numerous adjustments, rearrangements, and the like without your consent. It also tends to have insufficient tweaking options (the few that are available are set/disabled in the registry).

If the kernel pages (swaps) without your consent [which it does constantly], delegates which processes get your CPU time, and decides which application deserves the most physical memory (and which get hardly any), it's not very difficult to believe it could change process priorities dynamically as well.

I could be wrong; perhaps ZSNES does explicitly set its priority level now. If so, perhaps that was implemented to reduce CPU usage (remember the 95-100% CPU usage 'bug' with the GUI's infinite loop?).

Deathlike2 · Post by **Deathlike2** » Sun Jan 23, 2005 5:47 pm

perhaps ZSNES does explicitly set its priority level now.

It does work in a sense... it changes the priority when you are running the ROM (normal, high if set in ZSNES's options and low when it is in the GUI)

If so, perhaps that was implemented to reduce CPU usage (remember the 95-100% CPU usage 'bug' with the GUI's infinite loop?).

That bug is still there (I believe it is, because it does show 100% CPU usage when the ZSNES GUI is on)... I only find it strange (unless the devs say otherwise) that the GUI is running at a low priority...

Esturk · Post by **Esturk** » Sun Jan 23, 2005 6:07 pm

Well I get 100% CPU usage while in the GUI. But when playing a game like Earthbound, it goes down to around ~30%.

Post by **pagefault** » Wed Jan 26, 2005 1:55 am

Well old versions of ZSNES used to set priority to low while in the GUI and then back to normal when in a game but this code was changed long ago so I don't see what could be changing the priority on ZSNES to low. This one is a mystery to me.

Deathlike2 · Post by **Deathlike2** » Wed Jan 26, 2005 3:11 am

Well old versions of ZSNES used to set priority to low while in the GUI and then back to normal when in a game but this code was changed long ago so I don't see what could be changing the priority on ZSNES to low. This one is a mystery to me.

Well, this hasn't changed though... at least in the Windows version.