DOSBox faster than the real thing! \ VOGONS

DOSBox faster than the real thing!

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First post, by TeaRex

Posted on 2009-11-04, 11:06

TeaRex Offline

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I have found that DOSBox with core=dynamic cycles=max will run DOOM's "doom -timedemo demo1" faster than real MS-DOS 7.10 (i.e. a stripped down Win98 that boots into DOS) on my system. (E8400, nVidia 8600, 3GB RAM, Vista 32bit).

I get roughly 990 realtics in DOSBox and about 1145 realtics in MS-DOS. This is both with sound in DOOM disabled, since I don't have a DOS compatible sound card.

Good job guys (and gals if any)!

But I'm wondering how this can be... is the Core2Duo so much slower at running in real mode than in protected mode (note I'm not loading EMM386 in DOS)? Or is the PCI-E bus running slower when Windows is not booted?

tearex

Reply 1 of 4, by Jorpho

Posted on 2009-11-04, 16:24

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Protected mode is generally supposed to be slower than real mode, actually.

Reply 2 of 4, by TeaRex

Posted on 2009-11-04, 17:02

TeaRex Offline

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Jorpho wrote:
Protected mode is generally supposed to be slower than real mode, actually.

Certainly was back in the 286/386 era, but I wonder if that's still the case today when the vast majority of x86 CPUs spend most of their time executing 32-bit protected mode code. It would make sense to treat real mode as the special case in CPU design and mostly optimize for good protected mode performance.

tearex