PII 233-300 Mhz runs perfectly except in daggerfall ?

[wyvernshill]

OK, weird thing and it's not v17 related since it also happens in v16 but ...

I can emulate the PII-233 at 100% in all games i tried : (even PII 266 and 300 Mhz are rock solid at 100% speed)

* Doom
* Descent 1 and 2
* Crusader games
* wing Commander 3 and 4
* Lands of Lore 2 (with and without 3dfx
* Quake 1

etc ...

But for some reason Daggerfall will not work correctly in anything above a pentium 75.
On any other processor faster than that the emulator gets slower and slower.
On a PII 266 it drops down to 50%
On a P 200 MMX it is a bit faster but only marginally.

So why not play on the P75 then ? It seems the game is struggling hard since it has hiccups, framerate drops (not the emulator, that stays at 100%) etc ...
So the game needs a faster processor to eliminate that but then the emulator itself buckles.

it IS a demanding game but not more than for instance Lands of Lore 2 or even Quake 1 ?

Is there a setting i could change that alleviates this ? I tried different videocards and soundcards even motherboards but it all behaves the same on that particular game.

Many thanks !

[omarsis81]

On what processor are you running that config? Ryzen 5000 series?

[wyvernshill]

No, i'm using a ryzen 9 3900x at stock speed.

On a PII 266 in Lands of Lore 2 using 3dfx CPU time is about 60% ( a few hours into the game already)
Carmageddon (software) runs flawlessly and that's all 3d as well. (CPU time at 88%)
But on Daggerfall it depends it chokes right at the start dungeon, most of the time CPU time spikes to 100% and the emulator slows down to +- 48%

[ecksemmess]

Must be some peculiar dynarec corner case. Unfortunate since Daggerfall is a landmark game. Can you try other old versions of PCem and see if it's the same? Maybe go all the way back to when the dynarec was first introduced, and see if it's always had this issue or if some PCem versions do better than others? That might help us begin to narrow it down.

UPDATE: hmm, check out the official system requirements for Daggerfall: https://help.bethesda.net/app/answers/d ... gerfall%3F

It's supposed to be playable on even a 486/66, so maybe the interpreter can bail you out? Try a fast DX4 without dynarec and you should be able to get the game running OK, I would think. If you still have the same problem even on interpreter, it's most likely your setup and/or your copy of the game that's the culprit.

[wyvernshill]

i shall do so sir

[ecksemmess]

Interpreter + top-of-the-line Overdrive chip might get you to a satisfactory framerate if all else fails.

[wyvernshill]

Yeah, just tried a 486 without dynarec and it plays correctly (albeit a bit slow), tried it with dynarec and it plays the same (a little less cpu time usage).

The slower pentiums and the overdrive chip do work correctly but it seems then the hitching is purely a hard drive issue ?

It still don't explain why faster processors seem to not be able to play this ?

[ecksemmess]

Could be a lot of things. If 486 dynarec is performing similarly to 486 interpreter (if I'm understanding you correctly?), then that's very telling. Maybe a Pentium-specific recompiler feature corner case? What happens when you compare, say, a 486/66 dynarec vs. Pentium-66 dynarec? Is the Pentium dramatically more problematic, even at the same clock speed? Or are you saying the slower Pentiums actually perform flawlessly, aside from the expected generally crummy framerates in-game?

[wyvernshill]

i must say not even the pentium 75 seems adequate, when entering the great hall with the large stairs in the beginner dungeon CPU usage on a P75 spiked to 100% again and everything slowed down.

I am now trying a P66 as you suggested.

[ecksemmess]

Yeah. You can also try P60, as well as the fast 486 options (DX4 100/120) on dynarec. When you experiment, try to figure out if the problem seems to be more caused by clock speed, or more caused by which CPU class you're using. The idea here is to narrow down the problem and rule things out.

[wyvernshill]

the 486 with pentium overdrive seems to run ok except for some cpu spikes that look like hard drive stutter (but they are cpu spikes)
Weirdly enough i just tried a PII 233 Mhz and disabled both caches in the BIOS and it runs well, just as well as the 486 ones.

[wyvernshill]

OK i just saw the following :

PII 233
CPU-cache = on
External cache = on
result = unplayably slow, CPU 100%

PII 233
CPU-cache = on
External cache = off
result = unplayable, CPU 100%

PII 233
CPU-cache = off
External cache = off
result = unplayable, even worse ! (which is normal)

PII 233
CPU-cache = off
External cache = on
result = perfect speed with small hickups but CPU usage +- 80 % PCEM at 100% speed all the time.

[wyvernshill]

the same thing happens with slower pentiums until they are so slow you land up in 486 territory

[ecksemmess]

OK, so that pretty much solves the mystery, I'd say.

PCem has always been quirky when it comes to cache emulation (or the lack thereof). I'm not sure what would need to be tweaked to make those other BIOS settings playable, but it could probably be done without too much fuss, in the form of a hacky workaround of some kind. Ultimately some sort of proper cache emulation will have to be added, but that may be a long way off. In the meantime, at least you can now play the game on the faster CPUs, right?

[leilei]

I don't have Daggerfall around (yeah I know freewared long ago, I just don't have a habit of installing Bethesda software for many reasons) but I wonder if loading Smartdrv also does anything about it... Windows wasn't mentioned anywhere here and neither were FAT32 partitions.

[wyvernshill]

@leilei

It's a pure dos 6.22 environment and smartdrv is indeed loaded with expanded memory, mouse and cd driver loaded (Phil's computer lab setup menu, i added smartdrv /x)
The hitching is indeed less with smartdrv loaded but the issue of the cpu cache slowing the emulator down in this game still remains.

But ... it IS playable now

[unreal9010]

I ran into the same issue described above when running Daggerfall Demo on an emulated PII 233 under Windows 95. I fixed the issue by turning internal CPU cache off in the BIOS. This also helped me reach stable 100% emulator speed in Krypton Egg 32 where PCem speed would otherwise be around 75%, however, a number of other games were working slower with internal CPU cache turned off.

[nuclear69]

Sorry for necroing, but wyvern's finds are still relevant, but his ultimate solution, is not a topic close one, let me explain:
Daggerfall is doomed by frequent falls through the floor/running inside a wall. Thing is, the fastest the CPU, the more likely one of those glitches will happen.
I found it impossible to finish a dungeon using PII 233 with internal cache disabled.
Even thought it gives the fastest/most stable gameplay, any bump in a wall, running up some stairs and you'll be reloading your save. I went as far as having to downgrade to AMD's 486 with 150mhz to manage to complete a dungeon.
Now I'm testing a Pentium 133mhz, seems to run a bit better than the 486, need to confirm how it'll handle the glitch. But heavy stutters do occur every now and then, so its far from a ideal setup.

[nuclear69]

Alright i have a progress. It seems freedos runs like shit over pcem, I switch to dos 6.22 and its night and day difference. Stutters are not heavy, new areas load in a blink and the game itself takes half the time to start up. Emulation still strugles in big open areas If i pick a machine faster than a Pentium 100, but It improves in the test builds and I can't go much faster anyway or I get too many pitfalls. Overall it's Very enjoyable now, way better than dosbox.

[harrison98]

In response to the OP (from two years ago, but for the sake of new readers): This is the same dynamic recompiler issue that Terminator: Future Shock has, as reported various places:

https://github.com/sarah-walker-pcem/pcem/issues/169

Both Daggerfall and Terminator: Future Shock run on Bethesda's XnGine game engine. As stated in this thread, the solutions are to either run it on a 486 where dynarec can be disabled or to turn off internal cache on a Pentium CPU (which essentially disables the dynarec).