It really depends on the host due to the current dynarec, I mean, if you want a perfect 100% speed in the Pentium MMX at 200Mhz, you need that 4.2GHz machine.

SA1988 wrote:

It really depends on the host due to the current dynarec, I mean, if you want a perfect 100% speed in the Pentium MMX at 200Mhz, you need that 4.2GHz machine.

Changing that setting to 1 makes it run flawlessly. If I overclock my i7-870 to 3.9ghz should I expect to be able to run, say, a pentium 75 (since that's about 30% faster than a 486-100)

bluejeans wrote:

I'm trying to run dos doom (it's a long story why, want to see how old mods run on older hardware) and the highest emulated cpu I can get running at 100% if about a 486dx25, on an i7-870 (stock 2.93ghz).

Um, that's odd. Became single-core performance of current x86 generations that poor ? 😕
I ran an emulation of a 486DX50 in PCem on an AMD K9 dual-core (~12 years old system) at full speed (no dynarec).
In 2016, I've taken a screenshot of it running an NES emulation on Win 3.1 :
Re: A problem when trying to install a Living books game on Windows 3.1 on PCem.

bluejeans wrote:

On my i5 4690k at 4.2ghz overclocked cpu's all the way up to a pentium 200mmx run flawlessly at 100% emulation speed.
Is there really such a huge performance difference with my two systems or should I be looking into something else causing the problem?

Do you need MMX support ? I'm asking, because the Pentium MMX is more complex than a 486.
On real hardware, a nifty design might be beneficial for performance.
But in emulation, that's not always the case. In an Emulation, a simple design with a high cycle rate might be better.
If you like, try to play with the dynamic recomplier switch.

Edit: Several fixes.

Jo22 wrote:

Um, that's odd. Became single-core performance of current x86 generations that poor ? :?: I ran an emulation of a 486DX50 in […]
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bluejeans wrote:

I'm trying to run dos doom (it's a long story why, want to see how old mods run on older hardware) and the highest emulated cpu I can get running at 100% if about a 486dx25, on an i7-870 (stock 2.93ghz).

Um, that's odd. Became single-core performance of current x86 generations that poor ? 😕
I ran an emulation of a 486DX50 in PCem on an AMD K9 dual-core (~12 years old system) at full speed (no dynarec).
In 2016, I've taken a screenshot of it running an NES emulation on Win 3.1 :
Re: A problem when trying to install a Living books game on Windows 3.1 on PCem.

bluejeans wrote:

On my i5 4690k at 4.2ghz overclocked cpu's all the way up to a pentium 200mmx run flawlessly at 100% emulation speed.
Is there really such a huge performance difference with my two systems or should I be looking into something else causing the problem?

Do you need MMX support ? I'm asking, because the Pentium MMX is more complex than a 486.
On real hardware, a nifty design might be beneficial for performance.
But in emulation, that's not always the case. In an Emulation, a simple design with a high cycle rate might be better.
If you like, try to play with the dynamic recomplier switch.

I can exceed a pentium 90 with dynamic recompiler - why was it turned off to start with?

bluejeans wrote:

I can exceed a pentium 90 with dynamic recompiler - why was it turned off to start with?

To be honest, I'm not 100% certain. But I think it has to do with compatibility/stability.
Same reason why DOSBox has an auto core setting, I guess.

In an older PCem I tested, the dynarec did not work flawlessly with *some* 486 settings.
The emulated machine did POST, but it freezed or hang at the HDD detection/the boot process.
Entering CMOS SETUP did work fine, though.

Another thing I noticed with the dynarec was jerky performance in DOS sometimes.
Similar to running DOS in Virtual PC 200x with IVT/AMD enabled.

Jo22 wrote:

To be honest, I'm not 100% certain. But I think it has to do with compatibility/stability. Same reason why DOSBox has an auto co […]
Show full quote

bluejeans wrote:

I can exceed a pentium 90 with dynamic recompiler - why was it turned off to start with?

To be honest, I'm not 100% certain. But I think it has to do with compatibility/stability.
Same reason why DOSBox has an auto core setting, I guess.

In an older PCem I tested, the dynarec did not work flawlessly with *some* 486 settings.
The emulated machine did POST, but it freezed or hang at the HDD detection/the boot process.
Entering CMOS SETUP did work fine, though.

Another thing I noticed with the dynarec was jerky performance in DOS sometimes.
Similar to running DOS in Virtual PC 200x with IVT/AMD enabled.

How can I enable it in pcem, there's no line for it in its' .cfg file?

bluejeans wrote:

How can I enable it in pcem, there's no line for it in its' .cfg file?

In the menu bar, you can choose Settings->Configure to find a checkbox right below the emulated CPU type (486).
The line in the config file is "cpu_use_dynarec = 1".

86Box should have a similar setting (haven't used that since quite a while).

Jo22 wrote:

In the menu bar, you can choose Settings->Configure to find a checkbox right below the emulated CPU type (486). The line in the […]
Show full quote

bluejeans wrote:

How can I enable it in pcem, there's no line for it in its' .cfg file?

In the menu bar, you can choose Settings->Configure to find a checkbox right below the emulated CPU type (486).
The line in the config file is "cpu_use_dynarec = 1".

86Box should have a similar setting (haven't used that since quite a while).

What should I be able to emulate with a q6600? I'm guessing the emulator only uses a single thread? Single-threaded performance is about 30% less than my 870.

bluejeans wrote:

Jo22 wrote:

In the menu bar, you can choose Settings->Configure to find a checkbox right below the emulated CPU type (486). The line in the […]
Show full quote

bluejeans wrote:

How can I enable it in pcem, there's no line for it in its' .cfg file?

In the menu bar, you can choose Settings->Configure to find a checkbox right below the emulated CPU type (486).
The line in the config file is "cpu_use_dynarec = 1".

86Box should have a similar setting (haven't used that since quite a while).

What should I be able to emulate with a q6600? I'm guessing the emulator only uses a single thread? Single-threaded performance is about 30% less than my 870.

With my Q6600 PC @ stock (2.4Ghz), I'm just about able to do a decked out 486DX2-66 rig without NukedOPL (it uses tons of CPU time). A Pentium-75 runs at full speed in some games but only at ~75% in others, a K5-75 hovers between ~80-100%.

Overclocking, if your board supports it, should help, as will overclocked/fast RAM. (DDR2-800/1066, DDR3 1066/1333)

Sorry to piggy back here, but I also noticed that when I start up a Win98 machine in the latest PCEM, the audio is smooth. When I do the same with 86Box it sounds a bit choppy. It doesn't matter what CPU I pick. It's almost like the default buffering options are different between the two emulators.

Anyone else experience that? I like the features of 86Box more than PCEM, but PCEM seems a bit more polished.

valnar wrote:

Sorry to piggy back here, but I also noticed that when I start up a Win98 machine in the latest PCEM, the audio is smooth. When I do the same with 86Box it sounds a bit choppy. It doesn't matter what CPU I pick. It's almost like the default buffering options are different between the two emulators.

Anyone else experience that? I like the features of 86Box more than PCEM, but PCEM seems a bit more polished.

Probably because of the renderer, PCem has wx-sdl2, but 86Box still has DDraw and Direct3D, in any case, you can use the Epox machine which doesn't have choppiness.

My change from the ASUS P55-T2P4 (since I owned one previously) to the EPOX P55-VA didn't seem to matter, but I'll stick with that one now.

One major advantage that PCEM has that 86box does not is using your actual CD drive. I know I sound old but I still love it for games with copy protection on them: IE: Need For Speed High Stakes won't run on any sort of ISO type image: