I've got an old Toshiba M50-244 laptop that came with a celeron m 1.4 Ghz processor and I acquired a pentium m 1.7 Ghz processor which I "upgraded" it to. The laptop chipset is an ATI xpress 200M which according to the spec should support this CPU and speedstep. Unfortunately it seems toshiba's BIOS is crippled and has no way of enabling speedstep and so the CPU currently runs at its lowest speed setting by default (around 600Mhz) with no apparent way to change it. I've downloaded the Phoenix BIOS editor and had a look at a copy of the BIOS I currently have installed but I can't see any obvious way of setting speedstep (I guess I was hoping for a "speedstep enabled", yes/no setting). Without more understanding of the bios structure I can at best make wild guesses as to what sections to edit if its even possible via a bios mod. I'm not bothered about having it selectable in the bios, just being always on would be fine. Any assistance would be appreciated.
I just had a similar process with my A135-4656. Came with Celeron 520, upgraded to T2050. When it first booted with the T2050 it only ran at the lowest multiplier. I found in the BIOS "advanced" section, an entry for the speedstep control (sorry, I don't have the machine right now and do not remember the exact label). This entry had no value, so you couldn't easily tell what it was for. Once you select this label, you see that the values for it include the program control option, which is what you want. Sorry, I don't remember the details better. Go to the advanced tab, look for a label without a value. That's where you need to modify.