Uhm a Pentium III going for 300Mhz but i think a pentium MMX 233 using setmul + a voodoo 2 is what you are searching, a pentium 3 will be too fast for a number of DOS games, also i wouldn't describe softwares limiting speed emulation, setmul does just that and it's 100% going to give you the real deal experience you search.

The sweet spot would be the VIA C3 Ezra-T 1000 MHz, which easily runs at 1.2 - 1.26 GHz. Not an Intel, but it doesn't have to be. 😀
At its maximum speed, the Ezra-T CPU is similar to a Pentium 3 Katmai @ 600 MHz.

What is special about this CPU, though, is that it's the most speed-flexible CPU that I know of (it can hit ANY possible speed point all the way down to a slow 386).
Now, I've never tested the Ezra-T on an MSI MS-6153, however I did test it on an MSI MS-6163 ver 1 and it worked perfectly (using a slotket).

Another option would be the VIA C3 Nehemiah 1.2 GHz which easily runs at 1.4 - 1.46 GHz. This CPU is much faster than the Ezra-T (equivalent to ~ an 800 MHz Athlon), however it's not as flexible. It can only hit the following speed points: 286, slow 386, fast 386, 486SX-20, and then there's a huge gap up to the speed of ~ a Pentium 133. This is not usually a problem and most DOS games will work perfectly fine with these speed options (I know that all of my favorite DOS games do).

So, it depends what you prefer: more speed in Win98 but less flexibility (VIA C3 Nehemiah) or less speed in Win98 but what is arguably the best speed flexibility (VIA C3 Ezra-T).

You can set FSB to 66Mhz in BIOS and your Pentium !!! 733 will be 366MHz 😀

zyga64 wrote on 2022-08-26, 07:54:

You can set FSB to 66Mhz in BIOS and your Pentium !!! 733 will be 366MHz 😀

It won't make a difference for speed sensitive DOS games. 😀

bloodem wrote on 2022-08-26, 07:56:

zyga64 wrote on 2022-08-26, 07:54:

You can set FSB to 66Mhz in BIOS and your Pentium !!! 733 will be 366MHz 😀

It won't make a difference for speed sensitive DOS games. 😀

Original Celeron Medocino will not be suitable here either.
...but he can still try to disable the cache.

zyga64 wrote on 2022-08-26, 08:00:

Original Celeron Medocino will not be suitable here either.
...but he can still try to disable the cache.

Disabling the cache on any Pentium 3 up to 1 GHz results in a speed equivalent to a very slow/slow/normal 386 (depending on the frequency of said Pentium 3). This can be enough for many games, but there will also be many that don't run at their optimal speed.

joeguy3121 wrote on 2022-08-26, 04:23:

And No, I'm not gonna use tools to slowdown the computer or use a emulator as a alternative. I bought a retro gaming PC for the real deal authentic experience of playing old PC games the way their ment to function on during that period and I can live without 60 fps or higher on my 98SE.

It depends what you mean by "tools". The VIA C3 CPUs that I recommended are natively speed flexible (so they don't require any software slowdown/emulation to achieve lower speeds), however you do need to rely on tools like setmul to disable caches, change the multiplier, etc. And this will be the case for all CPUs. You won't find any CPU that is both fast for Win95/98 and also slow for DOS. 😁
If you don't want any tools, then be prepared to spend a lot of money to buy separate PCs: slow 386, fast 386, slow 486, fast 486, Pentium, etc. 😀

iraito wrote on 2022-08-26, 05:16:

Uhm a Pentium III going for 300Mhz but i think a pentium MMX 233 using setmul + a voodoo 2 is what you are searching, a pentium 3 will be too fast for a number of DOS games, also i wouldn't describe softwares limiting speed emulation, setmul does just that and it's 100% going to give you the real deal experience you search.

"Also, my motherboard won't support Pentiums below III as it lacks a Slot 1, so my only choice for CPUs with frequency below 450MHz are the Celeron Mendocino models."

I've already had to take my PC in after my previous motherboard broke and I'm not gonna replace it again but with a completely different motherboard just for a CPU....

bloodem wrote on 2022-08-26, 07:36:

The sweet spot would be the VIA C3 Ezra-T 1000 MHz, which easily runs at 1.2 - 1.26 GHz. Not an Intel, but it doesn't have to be […]
Show full quote

The sweet spot would be the VIA C3 Ezra-T 1000 MHz, which easily runs at 1.2 - 1.26 GHz. Not an Intel, but it doesn't have to be. 😀
At its maximum speed, the Ezra-T CPU is similar to a Pentium 3 Katmai @ 600 MHz.

What is special about this CPU, though, is that it's the most speed-flexible CPU that I know of (it can hit ANY possible speed point all the way down to a slow 386).
Now, I've never tested the Ezra-T on an MSI MS-6153, however I did test it on an MSI MS-6163 ver 1 and it worked perfectly (using a slotket).

Another option would be the VIA C3 Nehemiah 1.2 GHz which easily runs at 1.4 - 1.46 GHz. This CPU is much faster than the Ezra-T (equivalent to ~ an 800 MHz Athlon), however it's not as flexible. It can only hit the following speed points: 286, slow 386, fast 386, 486SX-20, and then there's a huge gap up to the speed of ~ a Pentium 133. This is not usually a problem and most DOS games will work perfectly fine with these speed options (I know that all of my favorite DOS games do).

So, it depends what you prefer: more speed in Win98 but less flexibility (VIA C3 Nehemiah) or less speed in Win98 but what is arguably the best speed flexibility (VIA C3 Ezra-T).

I guess I should of mentioned the version of the MSI motherboard I have which is a Ver:2.1.

How slow does the VIA C3 Ezra-T 1000 MHz perform in Windows games?

bloodem wrote on 2022-08-26, 07:56:

zyga64 wrote on 2022-08-26, 07:54:

You can set FSB to 66Mhz in BIOS and your Pentium !!! 733 will be 366MHz 😀

It won't make a difference for speed sensitive DOS games. 😀

I already have the solution for speed sensitive DOS games, which is turning off the cache in the BIOS settings. 😁

zyga64 wrote on 2022-08-26, 08:00:

bloodem wrote on 2022-08-26, 07:56:

zyga64 wrote on 2022-08-26, 07:54:

You can set FSB to 66Mhz in BIOS and your Pentium !!! 733 will be 366MHz 😀

It won't make a difference for speed sensitive DOS games. 😀

Original Celeron Medocino will not be suitable here either.
...but he can still try to disable the cache.

This. I in fact do disable the cache for speed sensitive DOS games.

What's this FSB you speak of?

joeguy3121 wrote on 2022-08-26, 08:16:

How slow does the VIA C3 Ezra-T 1000 MHz perform in Windows games?

As I said, it can basically hit ANY speed point. So, in small increments, it can perform like a Pentium 3 Katmai 600, a Pentium 3 500, Pentium 2 400, Pentium 2 300, Pentium MMX 233, Pentium MMX 166, etc, etc, etc.

joeguy3121 wrote on 2022-08-26, 08:18:

I already have the solution for speed sensitive DOS games, which is turning off the cache in the BIOS settings. 😁

If this works for the games you play, it's fine. 😀 In my case, some games need a bit more speed than that of a slow 386 (but not TOO much speed either).

joeguy3121 wrote on 2022-08-26, 08:23:

What's this FSB you speak of?

Check the "CPU Plug & Play II" BIOS menu (the option "CPU Host/PCI Frequency"). You can find out more details by reading your motherboard's manual and this Wikipedia article.

joeguy3121 wrote on 2022-08-26, 08:23:

What's this FSB you speak of?

Front Side Bus. For your Pentium 3 it is 133MHz. Cpu speed is FSB (133) x Multiplier (5.5). Multiplier is fixed.
5.5 x 66.6 is ~ 366 MHz

bloodem wrote on 2022-08-26, 08:27:

As I said, it can basically hit ANY speed point. So, in small increments, it can perform like a Pentium 3 Katmai 600, a Pentium […]
Show full quote

joeguy3121 wrote on 2022-08-26, 08:16:

How slow does the VIA C3 Ezra-T 1000 MHz perform in Windows games?

As I said, it can basically hit ANY speed point. So, in small increments, it can perform like a Pentium 3 Katmai 600, a Pentium 3 500, Pentium 2 400, Pentium 2 300, Pentium MMX 233, Pentium MMX 166, etc, etc, etc.

joeguy3121 wrote on 2022-08-26, 08:18:

I already have the solution for speed sensitive DOS games, which is turning off the cache in the BIOS settings. 😁

If this works for the games you play, it's fine. 😀 In my case, some games need a bit more speed than that of a slow 386 (but not TOO much speed either).

joeguy3121 wrote on 2022-08-26, 08:23:

What's this FSB you speak of?

Check the "CPU Plug & Play II" BIOS menu (the option "CPU Host/PCI Frequency"). You can find out more details by reading your motherboard's manual and this Wikipedia article.

Whoops! miss the "it can hit ANY possible speed point all the way down to a slow 386" part. 😅

A CPU that can change speed points sounds awsome and game changing. 👍🏼

Although I must say that before I made the decision to downgrade my CPU, my former intension was upgrading it to a Pentium III 1.00 GHz, unfortunately, I've just learned that the MS-6153 Ver: 2.1 would only go up to 733MHz and wouldn't post on a PIII 1.00 GHz. I'm very unsure about the VIA C3 Ezra-T 1000 MHz <-- 1.0 GHz be willing to work on my motherboard, I don't let to feel disappointed again....🙁

zyga64 wrote on 2022-08-26, 08:38:

joeguy3121 wrote on 2022-08-26, 08:23:

What's this FSB you speak of?

Front Side Bus. For your Pentium 3 it is 133MHz. Cpu speed is FSB (133) x Multiplier (5.5). Multiplier is fixed.
5.5 x 66.6 is ~ 366 MHz

I'll look into that later, Thanks.

joeguy3121 wrote on 2022-08-26, 09:14:

[...] unfortunately, I've just learned that the MS-6153 Ver: 2.1 would only go up to 733MHz and wouldn't post on a PIII 1.00 GHz. I'm very unsure about the VIA C3 Ezra-T 1000 MHz <-- 1.0 GHz be willing to work on my motherboard, I don't let to feel disappointed again....🙁

I have yet to see a motherboard that works with a lower speed Coppermine, but doesn't work with a higher speed Coppermine.
I can guarantee you that the MS-6153 works just fine with any Coppermine CPU, including the 1 GHz SKU. Something else must be going on... (i.e. how sure are you that the 1 GHz CPU you tested was not dead?).

bloodem wrote on 2022-08-26, 11:20:

joeguy3121 wrote on 2022-08-26, 09:14:

[...] unfortunately, I've just learned that the MS-6153 Ver: 2.1 would only go up to 733MHz and wouldn't post on a PIII 1.00 GHz. I'm very unsure about the VIA C3 Ezra-T 1000 MHz <-- 1.0 GHz be willing to work on my motherboard, I don't let to feel disappointed again....🙁

I have yet to see a motherboard that works with a lower speed Coppermine, but doesn't work with a higher speed Coppermine.
I can guarantee you that the MS-6153 works just fine with any Coppermine CPU, including the 1 GHz SKU. Something else must be going on... (i.e. how sure are you that the 1 GHz CPU you tested was not dead?).

I've bought the PIII 1.GHz refurbished, the best condition I could find. Maybe your right, I may go for the VIA C3 Ezra as soon as I settle this possible issue out.

IMO the ideal hybrid CPU is a VIA Ezra T or Nehemiah, but with the price and rarity of slotket adapters I think it is hard to recommend it.

Speed sensitivity is just not that important. I would choose a platform that makes sense for the games you want to play, and then think about how you can slow it down later if you need to. Any socket 370 CPU is going to be pretty flexible with a little tinkering. The number of games completely out of reach is close to zero.

mothergoose729 wrote on 2022-08-26, 16:42:

IMO the ideal hybrid CPU is a VIA Ezra T or Nehemiah, but with the price and rarity of slotket adapters I think it is hard to recommend it.

Well, the OP has a socket 370 motherboard (MSI MS-6153), so he won't need a slotket, no matter what CPU brand he chooses. 😀
The only question is whether his motherboard will work with the VIA Ezra-T / Nehemiah CPUs. I do know that the MSI MS-6163 (a great slot 1 board, that also has a 440BX chipset like the MS-6153) does work fine with these with the latest official BIOS.

Regarding slotket prices and rarity... yeah, not sure what's going on there. I have about ten Coppermine compatible slotkets that I purchased up until 2019 - 2020 for very little money ($5 - $10 a piece), but all of a sudden they're now extremely rare and expensive.

bloodem wrote on 2022-08-26, 07:36:

The sweet spot would be the VIA C3 Ezra-T 1000 MHz, which easily runs at 1.2 - 1.26 GHz. Not an Intel, but it doesn't have to be […]
Show full quote

The sweet spot would be the VIA C3 Ezra-T 1000 MHz, which easily runs at 1.2 - 1.26 GHz. Not an Intel, but it doesn't have to be. 😀
At its maximum speed, the Ezra-T CPU is similar to a Pentium 3 Katmai @ 600 MHz.

What is special about this CPU, though, is that it's the most speed-flexible CPU that I know of (it can hit ANY possible speed point all the way down to a slow 386).
Now, I've never tested the Ezra-T on an MSI MS-6153, however I did test it on an MSI MS-6163 ver 1 and it worked perfectly (using a slotket).

Another option would be the VIA C3 Nehemiah 1.2 GHz which easily runs at 1.4 - 1.46 GHz. This CPU is much faster than the Ezra-T (equivalent to ~ an 800 MHz Athlon), however it's not as flexible. It can only hit the following speed points: 286, slow 386, fast 386, 486SX-20, and then there's a huge gap up to the speed of ~ a Pentium 133. This is not usually a problem and most DOS games will work perfectly fine with these speed options (I know that all of my favorite DOS games do).

So, it depends what you prefer: more speed in Win98 but less flexibility (VIA C3 Nehemiah) or less speed in Win98 but what is arguably the best speed flexibility (VIA C3 Ezra-T).

I'm clueless, is this a VIA C3 Ezra-T 1000 MHz?.