VOGONS


overclocking

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First post, by french_whore

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I try to press ctrl+F12 repeatedly, but I see no change in CPU usage. It stays under 10% regardless of how many times or how frequently I press ctrl+F12. I have a really fast computer, that might be the problem.

Reply 1 of 11, by Lofty

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If you're just at the prompt with nothing running, it will have no effect. I mean, it'll increase the cycles, but there's no CPU emulation going on, so it doesn't actually use them. Try while running a game. Different games have different optimum cycles btw, for max speed. You want to aim for about 85-90% real CPU usage.

Reply 2 of 11, by icemann

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Wheres the "any key" ? 😜

Two stones, two crosses, the rest is just icing. - 7th Guest

Reply 3 of 11, by french_whore

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If you're just at the prompt with nothing running, it will have no effect. I mean, it'll increase the cycles, but there's no CPU emulation going on, so it doesn't actually use them. Try while running a game. Different games have different optimum cycles btw, for max speed. You want to aim for about 85-90% real CPU usage.

Ok, I guess that sorta helped, but not entirely. My CPU usage is holding at about 40% when in-game. The problem is, it's still not increasing when I press ctrl+F12.

Reply 4 of 11, by Lofty

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Do you have a CPU with hyperthreading support? That can cause windows to report CPU usage as half of what it really is with single-threaded apps like dosbox.

Reply 5 of 11, by french_whore

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Yep, that's the case. Does this mean my CPU usage is really approx 80%? That doesn't seem right, because Descent is running pretty slow, and it shouldn't be having problems on a 3GHz, 256mb vid computer (should it?)

Reply 6 of 11, by HunterZ

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If you have hyperthreading enabled, DOSBox will only ever be able to take advantage of half of your CPU power. Hyperthreading isn't all that useful on a gaming machine - it's more useful for servers and such.

Reply 7 of 11, by french_whore

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😒

thanks

Reply 9 of 11, by HunterZ

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Yes, usually in the BIOS as far as I know.

Reply 10 of 11, by `Moe`

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Hyperthreading won't give lower performance. Since the number of on-CPU arithmetic units is the same as with a normal single-core, non-HT CPU, you will at worst get a performance similar to a non-HT CPU. The only real difference is that Windows reports two CPUs while you actually have just one, which is why a single-threading program can only ever use 50% of the (theoretical) maximum. Nevertheless, a program running at 50% is using all of the available CPU.

3GHz is just enough for Descent. You need to edit dosbox.conf for optimum performance, see the countless descriptions in this forum, the README and elsewhere.

Reply 11 of 11, by Lofty

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Heh. I can *just about* play Descent on a 1Ghz Celeron if I turn the detail down. 😀
Dynamic core seems to work fine. At least in CVS.