RayeR wrote on 2023-11-23, 05:46:
I have BF2 wired to a solder jumper on my interposer and currently I configured it at HIGH (VCC3). This is correct for higher multipliers 4x and above, not? In the datasheet the highest described mul is 4x as BF2:0 = 1 0 0. I belived that further combinations like 1 0 1, 1 1 0, 1 1 1 gives me higher multiplier but for some reason it's capped at 4x. So it means that CPU treats this invalid combinations as 4x. If I set BF2 to 0, then I would probably get lower multis but this is not that I want. I don't remember how older Pentiums behaved but I though they didn't have capped multiplier but also they didn't overclock much so it didn't make sense anyway.
Well, so if a real 300MHz version exists and use mul 4,5x then it would probably use combination 1 0 1 as valid and maybe even higher - anybody has this CPU and tried? Intel could individually use LASER trimming to enable/disable max valid mul after chips binning.
If I recall correctly, if you pull it high it will enable 4x and may even lock it to 4x
Floating or pull down will enable 2x, 2.5x, 3x, 3.5x
If I recall from my experiments
I have found examples of p55 (and maybe p54?) who’s multis were locked and even scrambled.
P54 the max is 3x (can’t recall about locking but there were two cores, the prior didn’t go all the way to 3x)
P55 the max is 3.5x locks and scrambles have been observed
Tillamook the max seems to be 4x as the existence of 4.5 I have not as of yet been able to observe.
This is all from memory hopefully I remembered correctly feel free to correct.
There is no doubt that a 300mhz tillamook exists from intel, but I haven’t been able to observe a 4.5x in action or get anyone to post info from one, let alone find any verified info about its fsb/multi I kinda wonder if it is a 75mhz fsb chip?