Is this in regard to what the CPU is identified as in the POST screen?
Often the BIOS only correctly identifies known CPUs by approximation. Yours is possibly closest to the 100MHz P1 so BIOS may report it as such.
What does Speedsys report? Try updating the BIOS if the CPU is actually running at 133MHz.
Btw. even though it often runs just fine in S5 the 133MHz P1 is officially a S7 CPU. I think because of power supply specs.

The Pentium cpu does not have an Internal multiplier lock at 2x but relies on pins BF0 and BF1 to set multiplier. The board does not have Multiplier jumpers so pins BF0 and BF1 are locked at 3/2 or 1.5x by board design from what I can see...
The 133Mhz and 2x multiplier are your Pentiums Design criteria.... you could run it as low as 75Mhz on a 50mhz clock

Yes at the post screen it says its a Pentium-S (from memory) then 100MHz I haven't fully built it with a hard drive and Dos to use any CPU speed tests as I'm doing a RTC battery mod to fit a CR2032 coin battery, it would be great if the approximation is just reporting a 100MHz but actually running at 133MHz so I bet and hope your right I'll do a speed test after I'm done with the RTC, I haven't got another CPU for this S5 I'm down to my last one but I threw a P5 90MHz from another S5 board and it reported it as 90MHz when the jumpers were set to 60 and I also got 100MHz when set to 66 ~ this surprised me a bit a kind of quick overclock

Ok Horun thanks for that it looks like 100MHz is as fast as it will go, its odd that when I thought the jumpers were wrong and I was trying any configuration to get 133MHz I tried just one jumper and at the post it was 33MHz and was as slow as a 386 too

Sorry, I read your initial post like you configured the board for 2x multi but you were just listing specs.
You can probably simulate a BF0 jumper by bridging pins on the back of the mobo. It's probably not worth the hassle for 33MHz more though.😅