440BX does not support 133Mhz officially. Some utilities assume that CPU is just overclocked, since 100Mhz versions with that multiplier also exist.

red-ray wrote on 2019-08-22, 10:17:

SIV is designed for Windows NT so if you have both Windows NT/XP and 9X use the NT/XP system as more will be reported. Chances are that if something is zero or absent on 9x/Me the correct value will be reported on NT 3.51 and later.
As Windows 9X does not support kernel mode structured exception handlers (__try { … } _except() { … }) in VXDs SIV can't sensibly use a VXD to read MSRs so struggles with Pentium III and later CPUs on Windows 9X.

smtkr wrote on 2023-03-25, 19:15:

OS: Win98SE

CPU-Z 1.03.0.w9x - Specification: Intel Pentium III 600 MHz

SIV32L V5.69 Beta-06 - Says the FSB is 99.7MHz

It's down to it being 98SE, run SIV on NT 3.51 or later and I expect it will report correctly.

If you send me/post the SIV Menu->File->Save Local file I will see if I can read the 133 MHz from the 440BX chipset.

I wonder how CPUZ comes up with 600 MHz, my guess is that it's from MSR 17, post the CPUZ save file so I can check.

I have attached two versions of Intel utility, what so they report?

Here are the outputs from CPUZ and SIV. I'll come back with the other utils

Here's the output from the new files you posted.

smtkr wrote on 2023-03-25, 20:33:

Here are the outputs from CPUZ.

I ran SIV in debug mode using the CPUZ save file and the Maximum Multiplier in MSR 17 is 0B (x6) and the FSB in MSR 2A is 01 (133MHz).

Given this it is a 800EB and I suspect CPUZ reporting 600 MHz is down to a bug in CPUZ. This is confirmed by:

Expected processor Frequency: 800 MHz
Expected System Bus Frequency: 133 MHz

Thanks for checking on that for me

smtkr wrote on 2023-03-25, 20:33:

Here are the outputs from SIV.

Thank you for posting this. I looked at all the settings in 82443BX 440BX Chipset registers and there is nothing to show it's running @ 133 MHz 🙁

I am impressed by the low memory timings and wondering what DIMMs you use. When I checked the CPUZ save the DIMM SPD was missing so I could not check. I guess CPUZ does not support the SMBus multiplexor, SIV does, but only of Windows NT/2000/XP and later.

I'm running standard CAS2 Crucial sticks-2 256MB sticks in the 3rd and 4th slots. I used these on a Tyan Trinity 400 back in the day and was able to run 2-2-2.

I'm fiddling around with 440BX motherboards since I missed them when I was in my teens. The first one I got couldn't handle 133MHz FSB (recapped Abit BX6r2 from my other thread). The P3B here seems to not have any problems. I will experiment with Tualatins tomorrow.