If you have such issues then why run PPro at all? What will you use it for?

I'd use dual boot. Windows 98 and Win2K or NT4 (get a compatible sound card - much easier then a PPro system).

PS:
Also 16-bit apps on 32-bit OS take a hit.

kixs wrote:

If you have such issues then why run PPro at all? What will you use it for? […]
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If you have such issues then why run PPro at all? What will you use it for?

I'd use dual boot. Windows 98 and Win2K or NT4 (get a compatible sound card - much easier then a PPro system).

PS:
Also 16-bit apps on 32-bit OS take a hit.

To eventually replace my pentium 133 when it dies. The whole system was $10. I don't want to spend 50-100+ just to get another original pentium era machine.

If you want "optimal performance", why use a "pentium era" machine at all?

The question here is what exactly are you doing with the cpu? Pentium pros are plenty fast with 16 bit execution, but not much ahead of the p5, which is why it struggled in the consumer market. It does pull out ahead in 32 bit, and win98 is a hybrid 16/32 bit os so for general purpose computing (gaming) I would suggest windows 98. 16 bit executables WILL run faster on the pro vs an original pentium clock for clock

Im not sure if there are any real benefits with win2k or nt over Win98 SE when it comes to crunching with DWORDS (32 bit) since 98 has the win32 subsystem, but i can test if its really important to you

I think the best idea presented here is for you to dual boot 98 and NT 4.0. Win2k is a bit much as that came during the time of the Pentium III and any major game titles from 2000 and beyond will stomp that ppro. You can get pentium 2 and pentium 3 all the way up to coppermine machines with isa bus very cheaply if you want year 1999-2000 machine

bluejeans wrote:

kixs wrote:

If you have such issues then why run PPro at all? What will you use it for? […]
Show full quote

If you have such issues then why run PPro at all? What will you use it for?

I'd use dual boot. Windows 98 and Win2K or NT4 (get a compatible sound card - much easier then a PPro system).

PS:
Also 16-bit apps on 32-bit OS take a hit.

To eventually replace my pentium 133 when it dies. The whole system was $10. I don't want to spend 50-100+ just to get another original pentium era machine.

Why would P-133 die? 😉

My guess is that any 32-bit app/game will run fine (as fast as it was ment to be on PPro) on Win9X.

kixs wrote:

bluejeans wrote:

kixs wrote:

If you have such issues then why run PPro at all? What will you use it for? […]
Show full quote

If you have such issues then why run PPro at all? What will you use it for?

I'd use dual boot. Windows 98 and Win2K or NT4 (get a compatible sound card - much easier then a PPro system).

PS:
Also 16-bit apps on 32-bit OS take a hit.

To eventually replace my pentium 133 when it dies. The whole system was $10. I don't want to spend 50-100+ just to get another original pentium era machine.

Why would P-133 die? 😉

My guess is that any 32-bit app/game will run fine (as fast as it was ment to be on PPro) on Win9X.

It's dying already, every second boot the post hangs on a co-processor/time and date test. I don't want to spend $100 or so to just get another motherboard for it.

ppro an windows nt4 are a tandem or so i was told - you can use other combinations, but the optimal one is this; as for apps it will depend on what the app does;

I don't see what NT 4.0 has to do with it. Official DirectX support ended at version 3; you wouldn't want to use it for gaming, even if you could find drivers.

The heatsink on it is about double the size of the cpu, would it overclock ok to 200? Then I could drop my 133 to 100 and have a more spaced apart pair of specimens from the original pentium era (no need to get an ordinary pentium if it performs clock-for-clock on 9x)

Like I said: why do you want a "specimen from the original pentium era" if it's not fast enough for you?

Is there something you want to run on your 133 that doesn't run fast enough, but that you can't bear to run somewhere else?

He fears his P1 is going to be dead soon. A PPro is great for gaming. The PPro will be much faster for later DOS games than the P133.
IMO the ideal configuration is a dualboot with W9x and NT4 SP6. Gaming on NT4 is quite possible, despite the DX-limitation. OpenGL titles really fly, some would be surprised.

Overclocking a PPro 180 part to 200MHz is possible in many cases. Just try it at 66Mhz bus speed and test for stability.

FGB wrote:

The PPro will be much faster for later DOS games than the P133.

PPro is not enough for heavy DOS.

Why not drop a mmx pentium? Or 166mhz classic if you baoard can't take a mmx CPU. much cheaper. And you will not need a socket8 motherborad

The Serpent Rider wrote:

FGB wrote:

The PPro will be much faster for later DOS games than the P133.

PPro is not enough for heavy DOS.

Compared to a P133 a PPro180 probably @200MHz will be much faster.
"Not enough" depends on your definition of "heavy DOS".

The Serpent Rider wrote:

FGB wrote:

The PPro will be much faster for later DOS games than the P133.

PPro is not enough for heavy DOS.

What do you mean by heavy DOS? I ran windows 95 on my Pentium 133 back in the day.. There was no game or application for 16 bit DOS that the 133 didn't rip to shreds in my use, it even handled Win9x era games like Duke 3d quite well.

If OP needs the most power possible for a win9x / DOS hybrid I would suggest a Slot 1 machine.. I see OEM boards with a CPU combo running all the way up to coppermine 650s on ebay all the time very cheap with 2 ISA, PCI, and AGP. It will very likely be cheaper than looking for a socket 7 or super socket 7 machine. SDRam seems to be much cheap and easy to find in bulk, and a decent AGP card can be had for literally a couple dollars.

FGB wrote:

depends on your definition of "heavy DOS".

Something like Archimedian Dynasty. Later missions can kill performance of early PII with ease.

Also, I don't know what OP meant by "just 32 bit app". Possibly implying falsely that Windows 9x were 16 bit operating systems? They were still 32 bit protected mode with thunks to real mode and to 16 bit mode where necessary.

Fun random fact: Some random Windows 95 era games, like Toy Story (original) and Maui Mallard employed a graphics engine that made direct access to the framebuffer through MSDOS code, because DirectX didn't exist yet.

Another fun fact: The MPlayer or some other service port of Warcraft 1 was a DOS protected mode game with virtual extension calls to a Win32 process. The Win32 process basically hosted the Windows version of the Miles Sound System, and handled sound calls for the DOS game. It allowed some rather fun things for me, like the one time I used my OCD powers to create the map maximum count of human grunts, and clearcut the forest from an entire map before finally completing the final level ending objective. I just set them about, then put the game in the background, and proceeded to do other things to the merry sound of dozens of axe thunks per second going on for about 45 minutes.

kode54 wrote:

Another fun fact: The MPlayer or some other service port of Warcraft 1 was a DOS protected mode game with virtual extension calls to a Win32 process. The Win32 process basically hosted the Windows version of the Miles Sound System, and handled sound calls for the DOS game.

Similar technique is used by Open Cubic Player: one of the "soundcards" it supports is a vxd driver that plays sound through Win32 sound subsystem.
It worked on 9x but not on XP, as far as I remember.

The missing information here seems to be that Pentium Pros were bad at running 16-bit code because of the register renaming that was implemented as part of the Out-of-Order-Execution logic.
The key word here is 'partial register stall'.
That is, register renaming treats all registers, including 'partial' registers (eax being the full register, ax, ah and al the partial ones, for example) as separate internal registers.
However, there is overlap, so when another part of the register is accessed (eg, al was modified, then ax or eax is read), multiple internal registers need to be combined. This requires a pipeline flush to make sure that all register values are current.

Since 16-bit code always uses partial registers, this leads to excessive pipeline flushes in the Pentium Pro.
I don't think there's any 'special case' for realmode, because you cannot assume that you don't use 32-bit registers in realmode. Code can and will use the full 32-bit registers in realmode as well.

In the Pentium II this was fixed by adding some extra logic: when a full register is zero'ed (usually with xor eax, eax or such), the zero-flag also triggers a special state in the register renaming logic: Because it knows the full register was zero, there is no recombining required, and the pipeline flush can be skipped. Of course this still fails on legacy code where there's no explicit zeroing of the registers. But when you're in 16-bit mode, the registers start out as zero'ed, and the problem will not occur until you explicitly start using full 32-bit registers.
See also: http://qcd.phys.cmu.edu/QCDcluster/intel/vtun … rtial_Stall.htm
Pentium II also added caching for segment registers to improve 16-bit code performance.

So in short, I expect a Pentium Pro to be quite bad for DOS in general. But I've only used it with Win9x and NT4 myself, so I can't be 100% sure.
The problem is mixing registers of different sizes, either 16-bit and 32-bit or 8-bit and 16-bit. Especially legacy code will often use partial registers, because there was no penalty for it before the Pentium Pro. You could often optimize things considerably with clever use of partial registers.
Mixing 16-bit OS/BIOS code with 32-bit applications or vice-versa is both going to be a recipe for disaster on the Pentium Pro.
32-bit applications are no guarantee that they won't use partial registers though. The only 'good' 32-bit applications for Pentium II are ones that are compiled with a compiler that is Pentium II-aware, and always inserts the xor reg, reg sequence to avoid stalls. For Pentium Pro, even that doesn't really help, I believe.