kanecvr wrote:The Pentium PRO's cache is very speed sensitive... overclocking the CPU might be dangerous (you could end up damaging the cache)
I have never heard of anyone killing a Pentium Pro CPU if not letting it run very hot? My cooling is rather good 😀
I have now mapped out the FSB jumpers on the AIR P6NDI dual Socket 8 motherboard
JS1 to JS4
1-2, 1-2, 1-2, 1-2 = 60 MHz (This is the corrcet setting for 60 Mhz FSB if you go by the manual))
2-3, 1-2, 1-2, 1-2 = 60 MHz
1-2, 2-3, 1-2, 1-2 = No post
1-2, 1-2, 2-3, 1-2 = 55 MHz
1-2, 1-2, 1-2, 2-3 = 50 MHz
2-3, 2-3, 1-2, 1-2 = 60 MHz
1-2, 2-3, 2-3, 1-2 = No post
1-2, 1-2, 2-3, 2-3 = 66 MHz
2-3, 1-2, 1-2, 2-3 = 50 MHz
1-2, 2-3, 1-2, 2-3 = No post
2-3, 1-2, 2-3, 1-2 = 55 Mhz
1-2, 2-3, 2-3, 2-3 = No post
2-3, 1-2, 2-3, 2-3 = 66 MHz
2-3, 2-3, 1-2, 2-3 = 50 MHz
2-3, 2-3, 2-3, 1-2 = 55 MHz
2-3, 2-3, 2-3, 2-3 = 66 MHz (This is the correct setting for 66 Mhz FSB if you go by the manual)
Its clear that JS3 and JS4 is enough to set all 4 FSB options. The combination of JS1 1-2 and JS2 2-3 always fails to post regardless of the other FSB jumper settings.
Im wondering what JS1 and JS2 are used for...
I did also map the multiplier jumpers.
JSS1 to JSS4
Multiplier
JSS1 to JSS4
1-2, 1-2, 1-2, 1-2 = 2.0x
2-3, 1-2, 1-2, 1-2 = 2.5x
1-2, 2-3, 1-2, 1-2 = 3.0x
1-2, 1-2, 2-3, 1-2 = 4.0x
1-2, 1-2, 1-2, 2-3 = 2.0x
2-3, 2-3, 1-2, 1-2 = 3.5x
1-2, 2-3, 2-3, 1-2 = 2.0x
1-2, 1-2, 2-3, 2-3 = 4.0x
2-3, 1-2, 1-2, 2-3 = 2.5x
1-2, 2-3, 1-2, 2-3 = 3.0x
2-3, 1-2, 2-3, 1-2 = 2.0x
1-2, 2-3, 2-3, 2-3 = 2.0x
2-3, 1-2, 2-3, 2-3 = 2.0x
2-3, 2-3, 1-2, 2-3 = 3.5x
2-3, 2-3, 2-3, 1-2 = 2.0x
2-3, 2-3, 2-3, 2-3 = 2.0x
Well the multiplier jumpers are even more confusing than the FSB jumpers.
Its obvious that the CPU runs at 2x when it dosnt support the multiplier selected.
The function of JSS4 is a bit of a mystery.
There is no difference in speedsys mem score with the same multiplier and fsb using different jumper settings, for example the L2 cache stays activated.
Quake demo1 at 233 Mhz with a Matrox Mystique 4MB and a SB AWE 64: 46 FPS. Its not a very impressive score but I guess Quake is one of few games running faster on a vanilla Pentium at the same clock speed. The 512 KB CPU adds 4 FPS to the score and gets 50.1 FPS at 233 Mhz.
Its a bit annoying that a 512KB cache CPU performs better even in DOS as I would like to put those on my PR440FX board running NT4. I wonder if a P-Pro with 1MB cache can handle 233 MHz...