VOGONS


First post, by Zaxxon

User metadata
Rank Member
Rank
Member

Hi all I have a p3 cpu that I am trying to use to run some old dos games specifically Pyrotechnica by psygnosis. This game is very cycle sensitive, so much so that even running it in dosbox at the lowest cycles, will still run too fast, unplayable fast. Same does on my p3 cpy rig. I used a program calld "cpuspd" that allows me to slow down cpu by enabling or disablign caches l2 etc. this works on some sindows games but seems to didjnt' work at all for dos games. what program do you suggest me to use for slowing down the cpu so much that this game (and possibly other) will become playable?

Reply 1 of 14, by RetroPCCupboard

User metadata
Rank Oldbie
Rank
Oldbie

Some utilities here that you could try:

List of Slowdown Utilities (Beta)

But I think, in general, PII and PIII are not very suited to be slowed down. At least not in a very granular manner. First Gen PII at least had unlocked multiplier though which helped. My Pentium II 300Mhz can go down to 133Mhz I think.

Reply 2 of 14, by Gmlb256

User metadata
Rank l33t
Rank
l33t

There are very few options as P6-based CPUs aren't flexible.

Does your motherboard have SoftMenu-like features in the BIOS settings? That will allow you to change the FSB speed. Related to this, some utilities such RayerR's SMB (DOS) and SoftFSB (Windows) will let you do the same on the fly provided that the PLL clock generator chip on the motherboard is supported, especially the former.

A very less known method is setting the CPU cache mode to write-through with CM but it only works in real mode or if JEMM is loaded.

Lastly, there is also the hardware-based Throttle Blaster. Similar to ACPI throttling but very granular.

Reply 3 of 14, by Zaxxon

User metadata
Rank Member
Rank
Member
RetroPCCupboard wrote on 2024-12-21, 21:01:

Some utilities here that you could try:

List of Slowdown Utilities (Beta)

But I think, in general, PII and PIII are not very suited to be slowed down. At least not in a very granular manner. First Gen PII at least had unlocked multiplier though which helped. My Pentium II 300Mhz can go down to 133Mhz I think.

I see. keep in mind that last time i played that game on a real life rig was right when it came out in 1995, and i had a pentium 75, that cpu ran the game fine.

so which one of those is suited for a p3, for as slow as it can go?

Although i know it may sound stupid, i wanted to build a rig that had the best of both world, early win 95 games and late win 98 games, by having both a 3dfx + an s3 for old games AND an ATI radeon for late 90's games, (that i switch from bios according to what i need to play on boot). but for cpu seems like there is no solution ? 🙁

Last edited by Zaxxon on 2024-12-22, 09:01. Edited 1 time in total.

Reply 4 of 14, by Zaxxon

User metadata
Rank Member
Rank
Member
Gmlb256 wrote on 2024-12-21, 21:18:
There are very few options as P6-based CPUs aren't flexible. […]
Show full quote

There are very few options as P6-based CPUs aren't flexible.

Does your motherboard have SoftMenu-like features in the BIOS settings? That will allow you to change the FSB speed. Related to this, some utilities such RayerR's SMB (DOS) and SoftFSB (Windows) will let you do the same on the fly provided that the PLL clock generator chip on the motherboard is supported, especially the former.

A very less known method is setting the CPU cache mode to write-through with CM but it only works in real mode or if JEMM is loaded.

Lastly, there is also the hardware-based Throttle Blaster. Similar to ACPI throttling but very granular.

I think it has , where i can check specifically, as this bios has a ton more of options than usual bios? from the bios for example i choose wteher i want to use the AGP ati card for more "modern" games or use the s3 for old games.

"Lastly, there is also the hardware-based Throttle Blaster. Similar to ACPI throttling but very granular."

this one seems very good actually. does it need soldering of any kind or is let's say "plug and play"? I am crap with soldering unless is very basic stuff. My father could do that but his eyesight doesn't allow him to do very small solderings anymore

Reply 5 of 14, by Gmlb256

User metadata
Rank l33t
Rank
l33t
Zaxxon wrote on 2024-12-22, 09:00:

I think it has , where i can check specifically, as this bios has a ton more of options than usual bios? from the bios for example i choose wteher i want to use the AGP ati card for more "modern" games or use the s3 for old games.

There should be a section for the CPU configuration where the multiplier (if unlocked), FSB and core voltage can be adjusted. If those aren't present, then the motherboard doesn't have the feature.

"Lastly, there is also the hardware-based Throttle Blaster. Similar to ACPI throttling but very granular."

this one seems very good actually. does it need soldering of any kind or is let's say "plug and play"? I am crap with soldering unless is very basic stuff. My father could do that but his eyesight doesn't allow him to do very small solderings anymore

It does need soldering skills.

Reply 6 of 14, by myne

User metadata
Rank Oldbie
Rank
Oldbie

Guessing the throttleblaster hijacks the prochot function on the power monitor chip?

I built:
Convert old ASUS ASC boardviews to KICAD PCB!
Re: A comprehensive guide to install and play MechWarrior 2 on new versions on Windows.
Dos+Windows 3.11+tcp+vbe_svga auto-install iso template
Script to backup Win9x\ME drivers from a working install
Re: The thing no one asked for: KICAD 440bx reference schematic

Reply 7 of 14, by Zaxxon

User metadata
Rank Member
Rank
Member
Gmlb256 wrote on 2024-12-22, 13:18:
There should be a section for the CPU configuration where the multiplier (if unlocked), FSB and core voltage can be adjusted. If […]
Show full quote
Zaxxon wrote on 2024-12-22, 09:00:

I think it has , where i can check specifically, as this bios has a ton more of options than usual bios? from the bios for example i choose wteher i want to use the AGP ati card for more "modern" games or use the s3 for old games.

There should be a section for the CPU configuration where the multiplier (if unlocked), FSB and core voltage can be adjusted. If those aren't present, then the motherboard doesn't have the feature.

"Lastly, there is also the hardware-based Throttle Blaster. Similar to ACPI throttling but very granular."

this one seems very good actually. does it need soldering of any kind or is let's say "plug and play"? I am crap with soldering unless is very basic stuff. My father could do that but his eyesight doesn't allow him to do very small solderings anymore

It does need soldering skills.

ok found these on the bios, don't know if they are the values you were talking to.

I tried Cpugrab and somhow it works, it's not as granular as it should be, because while the game is actually slower, in some parts it ramps up faster, much faster. maybe the game was coded to use every ounce of power from the cpu, regardless that you like it or no

Reply 8 of 14, by Gmlb256

User metadata
Rank l33t
Rank
l33t
myne wrote on 2024-12-22, 14:00:

Guessing the throttleblaster hijacks the prochot function on the power monitor chip?

Throttle Blaster uses the STPCLK# pin from the Socket/Slot to perform its functionality.

Zaxxon wrote on 2024-12-22, 09:00:

ok found these on the bios, don't know if they are the values you were talking to.

Yes, those are the values that I'm talking about. CPU speed setting is the safest one to use, 300 MHz would set the FSB to 66 MHz (66 x 4.5 = 300 MHz). It is still too fast for some speed-sensitive games, but it can be combined with slowdown utilities.

Reply 9 of 14, by myne

User metadata
Rank Oldbie
Rank
Oldbie
Gmlb256 wrote on 2024-12-22, 16:42:
Throttle Blaster uses the STPCLK# pin from the Socket/Slot to perform its functionality. […]
Show full quote
myne wrote on 2024-12-22, 14:00:

Guessing the throttleblaster hijacks the prochot function on the power monitor chip?

Throttle Blaster uses the STPCLK# pin from the Socket/Slot to perform its functionality.

Zaxxon wrote on 2024-12-22, 09:00:

ok found these on the bios, don't know if they are the values you were talking to.

Yes, those are the values that I'm talking about. CPU speed setting is the safest one to use, 300 MHz would set the FSB to 66 MHz (66 x 4.5 = 300 MHz). It is still too fast for some speed-sensitive games, but it can be combined with slowdown utilities.

Right. That's what the hardware monitor triggers when prochot (processor hot) is active.

Iirc the winbonds can trigger it for as high as 70% duty cycle (Ie 30% of the speed)

I built:
Convert old ASUS ASC boardviews to KICAD PCB!
Re: A comprehensive guide to install and play MechWarrior 2 on new versions on Windows.
Dos+Windows 3.11+tcp+vbe_svga auto-install iso template
Script to backup Win9x\ME drivers from a working install
Re: The thing no one asked for: KICAD 440bx reference schematic

Reply 10 of 14, by Zaxxon

User metadata
Rank Member
Rank
Member
Gmlb256 wrote on 2024-12-22, 16:42:
Throttle Blaster uses the STPCLK# pin from the Socket/Slot to perform its functionality. […]
Show full quote
myne wrote on 2024-12-22, 14:00:

Guessing the throttleblaster hijacks the prochot function on the power monitor chip?

Throttle Blaster uses the STPCLK# pin from the Socket/Slot to perform its functionality.

Zaxxon wrote on 2024-12-22, 09:00:

ok found these on the bios, don't know if they are the values you were talking to.

Yes, those are the values that I'm talking about. CPU speed setting is the safest one to use, 300 MHz would set the FSB to 66 MHz (66 x 4.5 = 300 MHz). It is still too fast for some speed-sensitive games, but it can be combined with slowdown utilities.

ok thanks will use that and try, thanks again 😀

the others are non-safe but can achieve bette results as in more slowness?

Reply 11 of 14, by Gmlb256

User metadata
Rank l33t
Rank
l33t
Zaxxon wrote on 2024-12-23, 18:59:

ok thanks will use that and try, thanks again 😀

the others are non-safe but can achieve bette results as in more slowness?

"CPU Bus/PCI Freq. (Mhz)" does achieve the same results. However, it is less safe due to having options that makes the PCI (33 MHz) and AGP (66 MHz) buses run out of spec. Some of these are only intended for overclocking.

The lowest one which is 66.8/33.40, does the same as selecting 300 MHz in "CPU Speed". Setting 100.3/33.43 will run the CPU frequency at 450 MHz.

If you want to put the CPU frequency back to 600 MHz, set it to 133.0/33.25.

Reply 12 of 14, by Joakim

User metadata
Rank Oldbie
Rank
Oldbie

You could try to turn off l2 cache and see where that gets you.

Reply 13 of 14, by Zaxxon

User metadata
Rank Member
Rank
Member
Joakim wrote on 2024-12-24, 09:26:

You could try to turn off l2 cache and see where that gets you.

from cpuspd you mean? did that and nothing changed, on dos games at least

Reply 14 of 14, by Zaxxon

User metadata
Rank Member
Rank
Member
Gmlb256 wrote on 2024-12-23, 19:16:
"CPU Bus/PCI Freq. (Mhz)" does achieve the same results. However, it is less safe due to having options that makes the PCI (33 M […]
Show full quote
Zaxxon wrote on 2024-12-23, 18:59:

ok thanks will use that and try, thanks again 😀

the others are non-safe but can achieve bette results as in more slowness?

"CPU Bus/PCI Freq. (Mhz)" does achieve the same results. However, it is less safe due to having options that makes the PCI (33 MHz) and AGP (66 MHz) buses run out of spec. Some of these are only intended for overclocking.

The lowest one which is 66.8/33.40, does the same as selecting 300 MHz in "CPU Speed". Setting 100.3/33.43 will run the CPU frequency at 450 MHz.

If you want to put the CPU frequency back to 600 MHz, set it to 133.0/33.25.

ah ok , no will stick to the manual ones , thanks 😀