[Help] constant 1000fps and over

[Monk]

Jiffies is the interrupt timer. It's very coarse and cause timers to tick at 10ms regardless of HZ.

[pengy]

Well, I tried jiffy on my system and it crashed after 1 minute... http://www.fpsmeter.org/p,view;10260.html first part is tsc, then hpet, then jiffy and then crash

[Peter_Pan123]

00:33:50 CPU In Out Uptime Users FPS Players
2.50 0.00 0.00 533 0 996.02 0

I think thats a lie ^^

I did a lot of tests > but with the kernel i got only ~940 FPS (lenny/64bit).

[BehaartesEtwas]

Monk Wrote:Jiffies is the interrupt timer. It's very coarse and cause timers to tick at 10ms regardless of HZ.

not quite. jiffies are derived from the timer interrupt, but that's true for any timing system (how else...). basically jiffies *are* the kernel HZ. clocksources like tsc or hpet don't depend on HZ, but jiffies do. that's why you can use HZ=100 and still achieve 1000 fps on systems with a working hpet clock ;-)

[Monk]

Incorrect. Jiffies *are* the timer interrupt. HZ=100 with jiffies doesn't mean anything because gettimeofday ticks at 10ms regardless of HZ with jiffies.

[pengy]

I'm confused

[djjerdog]

all this jiffies talk is making me want a pb&j...
sorry back on topic, how do you know if your motherboard supports HPET? Does it have to be a bios option?

[pengy]

Yes, somewhere in the advanced processor settings

[BehaartesEtwas]

<offtopic>
@monk: please stop confusing everyone by mixing all things. jiffies are a kernel construct, timer interrupts are hardware. it can't be the same. and btw: before hrtimes, the timer interrupt was programmed to fire with HZ, that is the meaning of HZ. of course jiffies are derived of that interrupt (what else? w/o hrtimers there was no other clock source!). now we have hrtimers and the world is more complicated but more precise. Don't simplify things too much, they get wrong then. But I guess we can end this discussion by agreeing that jiffies are an out-dated construct existing only for compatibility (more or less).
</offtopic>