i have an old Intel 440LX motherboard which for unknown reason ran at 75Mhz (instead of 66Mhz) with no trouble for 20 years while using a NIC card (Dlink DFE530TX) in PCI slot #1
Removing the card or changing PCI slot disabled the "unexpected overclocking". It looked like some kind of bug. (It was not random, nic card in pci#1 = 75Mhz 100% of the time)
The board, an MSI MS-6114 (Dual Slot 1) has no FSB jumpers, only an (inefective) ratio dipswitch.
I use two 333Mhz fanless Deschute Pentium II (They where working at 375Mhz).
Lately i replaced the PSU, because the old one was dying (noise). With the new PSU, to my dismay, i am back to 66Mhz ! I tried to reset bios, clear cmos, change pci port, everything, i am stuck to 66Mhz. It ticks me off ! :)
I may sound silly to overclock 20 years old Pentiums 2 but i am still using this computer for fun and i wonder if i can get back my 75Hz FSB by other mean.
If i understand correctly, looking at the MB the clock generator is an IMI SG584AYB
I haven't found anything about it on google. Some IMI PLL IC where supported by SoftFSB (old Windows program) but the SG584 is not listed.
i2cdetect -l
i2c-0 smbus SMBus PIIX4 adapter at 5f00
Not sure what to do. I sent a message to "Cypress semi-conductors" (who bought IMI in 2001) but i doubt they will make the effort to dig the datasheet.
Thank you !
Last edit: Corentin 2019-04-28
If you would like to refer to this comment somewhere else in this project, copy and paste the following link:
[root@crumble0]:~# i2cdetect 0WARNING! This program can confuse your I2C bus, cause data loss and worse!I will probe file /dev/i2c-0.I will probe address range 0x03-0x77.Continue? [Y/n] y 0 1 2 3 4 5 6 7 8 9 a b c d e f00: --------------------------10: --------------------------------20: --------------------------------30: --------------------------------40: --------------------------------50: --------------------------------60: --------------------------------70: ----------------
and during detect dmesg is full of (one line per address)
Hello,
i have an old Intel 440LX motherboard which for unknown reason ran at 75Mhz (instead of 66Mhz) with no trouble for 20 years while using a NIC card (Dlink DFE530TX) in PCI slot #1
Removing the card or changing PCI slot disabled the "unexpected overclocking". It looked like some kind of bug. (It was not random, nic card in pci#1 = 75Mhz 100% of the time)
The board, an MSI MS-6114 (Dual Slot 1) has no FSB jumpers, only an (inefective) ratio dipswitch.
I use two 333Mhz fanless Deschute Pentium II (They where working at 375Mhz).
Lately i replaced the PSU, because the old one was dying (noise). With the new PSU, to my dismay, i am back to 66Mhz ! I tried to reset bios, clear cmos, change pci port, everything, i am stuck to 66Mhz. It ticks me off ! :)
I may sound silly to overclock 20 years old Pentiums 2 but i am still using this computer for fun and i wonder if i can get back my 75Hz FSB by other mean.
If i understand correctly, looking at the MB the clock generator is an IMI SG584AYB
I haven't found anything about it on google. Some IMI PLL IC where supported by SoftFSB (old Windows program) but the SG584 is not listed.
Not sure what to do. I sent a message to "Cypress semi-conductors" (who bought IMI in 2001) but i doubt they will make the effort to dig the datasheet.
Thank you !
Last edit: Corentin 2019-04-28
Datasheet of SC643, used on the MS-6117 motherboard. Very similar but only one Slot-1
and picture of my MS-6114
Last edit: Corentin 2019-04-28
I think my biggest problem now is the i2cdetect :
and during detect dmesg is full of (one line per address)
-F data :
Last edit: Corentin 2019-04-30