This is one of the reasons its the Ultimate retro laptop. I used DOOM as a benchmark becasue speedsys gives inaccurate results favoring the PIII FPU over raw horsepower.
Doom benchmark at Speed step + 1x Throttle L1 enable l2 disable
I did some testing of speedstep and CPUspd on this laptop.
The goal was to slow it down to Dx2 66 speeds with L1 cache on.
Speed step works the same on all versions of the laptop as it drops all cpus to 700mhz . Speedstep ver 1 It's weird. Best I can explain is it actually change the base and the multiplier. Thats why you can go so much slower with speed step on.
The CPU in this laptop has 200 mhz Base clock with a 8.5 Multi. What speed step does is it drops the base clock to 174mhz with a 7X multi. CPUSPD allow you to thottle 700mhz by 8X. So with a 1X throttle the CPU runs at 85 mhz . It also is throttling the bus and the memory throughput is like 44mbs. Disabling the l2 but leaving the l1 enabled it makes the CPU act a lot like a 486 Dx2 66.
The I combine Speed step with south bridge throttling. I can then match the speed of a DX2 66 without disabling the l1 cache. Theres not a lot of granularity outside of this. But it does get you slow enough to play some speed sensitive title. I haven't tested much more than this.
Full speed. 8.5 Multi
Speed step on
Speed step @ 2X Throttle
Speed Step @ 1X throttle L1 cache on, L2 Cache off