Some pentium 2 300 MHz are multiple unlocked whereas pentium 3s are not.

Joakim wrote on 2022-02-22, 16:48:

Some pentium 2 300 MHz are multiple unlocked whereas pentium 3s are not.

You sure? I have a P3 500 & 500E and I couldn't change their multiplier.

https://www.vogonswiki.com/index.php/List_of_ … sensitive_games
Looking at the list there aren't many games that'll run on a slow Pentium II but not on a 600MHz Pentium III. I'd go for the Pentium III.

I think you misunderstand me, that's what I'm saying pentium 3 are multiple locked. 😀

Depends what old games. You're already too fast at 300mhz to worry about DOS compatibility with the 1-2 games that may or may not worth being played. There's only a few early Pentium class speed sensitive games. Wrath of Earth as example. However a utility like CPUSPD can throttle you slow enough to play that if you had a 600mhz PIII.

I think a 300MHZ PII is too slow. You can't play any late 90s games with that. The type game you can play on 300mhz PII is like Diablo 1 the 1st game forget diablo II.

Diablo 1 works quite fast on beefy 486DX4 🤣, so Diablo II is not an issue for PII. But in 3D - yes, PII 300 is very lackluster and can't handle Unreal or Half-Life by modern standards.

Sunflux wrote:

or is it already too fast such that I might as well get a 450mhz Pentium II or even a Pentium III 600mhz?\

PII 300 is interchangable with Pentium III 450/100 or Pentium III 600/133, because you can underclock both of them to 300/66 and Klamath core has almost identical to Pentium II performance . But ealry PII had unlocked downward multiplier, so 133 Mhz or even 100 Mhz downclock is possible for speed sensitive games.

Joakim wrote on 2022-02-22, 16:53:

I think you misunderstand me, that's what I'm saying pentium 3 are multiple locked. 😀

Whoops, but TIL Pentium 2's aren't, thanks!

It’s sounding like a P3-600/100 would be the way to go. If I got a 600B/133 I’d be forced to run it at 450mhz on this board version.

Speaking of which… if I DID go Slotket (although they seem way too expensive right now), what’s the max CPU this board could take? Asus only lists up to 600mhz for revision 1.02 and 800mhz for 1.04 (I love them for keeping full support up decades later, while Intel literally purged everything about boards nowhere near as old).

Sunflux wrote on 2022-02-22, 17:48:

It’s sounding like a P3-600/100 would be the way to go. If I got a 600E/133 I’d be forced to run it at 450mhz on this board version.

Speaking of which… if I DID go Slotket (although they seem way too expensive right now), what’s the max CPU this board could take? Asus only lists up to 600mhz for revision 1.02 and 800mhz for 1.04 (I love them for keeping full support up decades later, while Intel literally purged everything about boards nowhere near as old).

A slotket would be useless if you're stuck at 600MHz. Likely this means Katmai is the limit (Slot 1 only). I suppose there might be some faster Celeron support, but I don't have knowledge here (since I avoid them like the plague).

If your board can support Coppermine, then 1000MHz (or even 1100MHz? ... some boards like the SE440BX-2 won't accept the 1.1GHz Coppermine) could be as fast as you can go (without Powerleap, but now we're entering 'crazytown'). In any case, once you go above 600MHz for Slot 1 100FSB Pentium III's, prices begin to appreciate rapidly.

Question: if the board multiplier only goes up to 6X, does that actually matter if the CPU multiplier is locked? Like, why wouldn’t faster than 600 be supported? I know the reason Coppermine isn’t supported is due to not having low enough voltages, but I understand the Slotket is supposed to deal with that… and if I have the latest BIOS…?

Sunflux wrote on 2022-02-22, 18:07:

Question: if the board multiplier only goes up to 6X, does that actually matter if the CPU multiplier is locked? Like, why wouldn’t faster than 600 be supported? I know the reason Coppermine isn’t supported is due to not having low enough voltages, but I understand the Slotket is supposed to deal with that… and if I have the latest BIOS…?

It could be the case, when I think about it, I am probably mistaken. I've never had to deal with Coppermine voltage before.

And why not? I imagine that's what the manufacturer did (v1.04) for your board. A quality Slotket could do the same. I have an MSI Master MS-6905 Slotket, but I never needed it for voltage adjustment as the board (SE440BX-2) was already Coppermine compatible.

I could try it out. I have a DFI board limited to 600MHz/133 (overclock) 440BX. I'll pop in the Slotket with a faster Coppermine and see what happens if you like.

AirIntake wrote on 2022-02-22, 17:44:

Joakim wrote on 2022-02-22, 16:53:

I think you misunderstand me, that's what I'm saying pentium 3 are multiple locked. 😀

Whoops, but TIL Pentium 2's aren't, thanks!

Just to prevent misunderstandings: Some Pentium IIs aren't.

If the CPU's multiplier is locked, board settings are ignored. You can in theory run all Coppermine 100MHz FSB S370 CPUs on this board as long as your slotket can be used with them and can force 1.8Vcore.

In practice though unlikely there may be issues with the board's VRM not being able to deliver stable voltage at higher speeds and BIOS may not recognise/handle the CPU right.

Meatball wrote on 2022-02-22, 18:17:

I could try it out. I have a DFI board limited to 600MHz/133 (overclock) 440BX. I'll pop in the Slotket with a faster Coppermine and see what happens if you like.

Thanks very much for the offer, but you don’t need to do that! I can probably dig up some info with some Google-fu.

I’m just uncertain because Asus only lists up to 800mhz WITH their Slotket adapter AND only on 1.04, but that could just be because they stopped updating the list after 1999 (faster than 800 came out in 2000). Or maybe their adapter didn’t change voltage…

The last BIOS is from August 2002, however, so it’s possible it has support.

Sunflux wrote on 2022-02-22, 18:07:

[…] but I understand the Slotket is supposed to deal with that… and if I have the latest BIOS…?

Slotkets do NOT typically have onboard Voltage regulators (there are some that do, however those are practically unobtainium).
The typical slotket simply manipulates the voltage request signal, to make the motherboard think that the CPU needs a particular voltage. If the motherboard can’t provide said voltage, then this slotket feature is useless.
As a workaround, you could force 1.8V for Coppermine CPUs (and this voltage should be supported by older motherboards as well). This way you should at least get a POST (some boards might still refuse to POST if the BIOS does not recognize the processor) , but your CPU will run at a pretty high non-native voltage, so extra cooling would be advisable).

bloodem wrote on 2022-02-22, 18:33:

Slotkets do NOT typically have onboard Voltage regulators (there are some that do, however those are practically unobtainium).

Thanks, that clears up a lot. I was under the mistaken impression that the voltage selection jumpers and extra circuitry on many Slotkets meant they actually provided a compatible voltage regardless of input. I knew that Slotket-Ts were the holy grails… but I thought that was simply for even newer CPU support.

I see there was Katmai 600/133 and 600/100. You will be better off with the latter.

Katmai 600/100 (marked as 600/100/2.05V - *not* 600E or 600B or 600EB) would be the official highest CPU Asus would endorse, but that might be hard to find at a good price (I haven't looked).

If you get a Coppermine slocket with VID jumpers and set it to 1.8V then your board will power it up and it will work with a BIOS update. Running Coppermines at 1.8V was/is a popular move for slot-1 upgrades and I don't think I've ever read of it being a problem, but it will add some heat. I think the highest voltage Intel themselves used was 1.75V. It will still be less heat than you'd get from a Katmai.
The only downside with this approach IMO is the fact that it's a slocket, which makes it bulkier than a native slot-1 CPU, might overhang or block RAM slot(s), and might feel a little clunky aesthetically.

The Asus P2B series boards were very popular and have good BIOS support for Coppermines. The last Beta release even works with Tualatins (but there's more shenanigans involved with those on the electrical side which I don't know about).
I've never used a P2B-LS variant but I think it's BIOS would be just as good as the more common P2B boards.
The most I've pushed these boards myself was with a pair of systems that each had a P3-600E clocked at 800/133 on P2B-F boards which were used reliably for over a year. I was using standard voltage though (they had Coppermine compatible VRMs on them).
Back when they were easier to get, I bought a Celeron 1100 to stress test 440BX boards that I was selling, but I can't remember if I ever did that on the P2B. I think it would be fine though.

Can you see what part number you have on your voltage regulator chip? It's something like 20 pins or so, in the area between the CPU slot and the peripheral ports, near the MOSFETs. This is the best way to determine if it supports < 1.8V, rather than going by the board revision. Many boards have the later regulators on them despite being an earlier revision that wasn't guaranteed to have it. This would open the option of native slot-1 Coppermines, though those get expensive at higher speeds.

I'm pretty certain my board was bought prior to Coppermine's release, but I've attached a picture of the chip (sorry, it was hard to get a good view due to a crossmember in the old case completely blocking access).

Today while poking around some old motherboard boxes, I discovered I also have a P3B-F board. I think it's the board I originally used with the P2-350. And it has 2 ISA slots, which is what I actually need.

Unfortunately it's revision 1.03, which according to ASUS is too old for Coppermine support (need 1.04). I've attached a picture of its chip too, since it seems... beefier.