First post, by melbar
- Rank
- Oldbie
Hello,
Last days, i have seen also the video about a "time-maschine - 4 in 1: 386, 486. Pentium & Full Speed" (from Phil's Computerlab) on youtube. This was a interesting projekt, so i also want to build something similar.
This weekend, i have got a Super-Socket 7 board now, combined with a AMD K6-2 500MHz. That means it run's with 5(multiplier) * 100MHz (FSB).
I have also download the manual and compared it to the settings on the motherboard PBC.
These are now the results of underclocking:
It's not possible to set exactly 66MHz FSB. The minimum FSB is 68MHz, whether you set it on 66MHz or 68MHz.
The board has the following multipliers:
-1.5x/3.5x
-2.0x
-2.5x
-3.0x
-4.0x
-4.5x
-5.0x
-5.5x
When i set [1.5x/3.5x] and [66MHz FSB], the result is 240MHz (that means 3,5*68,5=240).
When i set [2.0] and [66MHz FSB], the result is 411MHz (that means 6*68,5=411). This is exactly what i read in some forums: The K6-2 interprets the 2x multiplier as 6x.
When i set [2.5x] and [66MHz FSB], the result is 171MHz (that means 2,5*68,5=171).
Well, in his video (https://www.youtube.com/watch?v=fcAqRbFFQPU) Phil takes a K6-3+ and another Super Socket 7 Board. And he was able to set the processor exactly at 133MHz (2*66,0=133). So the processor does not interpret the 2x multiplier. Why? I Don't understand ... Has it something to do with the CPU stepping or is it the motherboard?
Ok, it is also possible to put a Pentium 1 (100MHz to 200MHz) onboard, but the question for me is:
Does the Intel Pentium (for example the P100 or P133) run with the correct multiplier, e.g. 1.5x and 2.0x, and does not interprets the multipliers wrong?
Well, compared to Phil's underclock (133MHz+ L1/L2 disable+ L3 disable = 386 Speed; 133MHz+ L1/L2 disable+ L3 enable = 486 Speed) i would have now 38Mhz more. The question is, what are the differences according to 386 / 486 and Pentium Speed?