On two different systems, I'm running dual PIII 650Mhz (6.5x100Mhz) processors in a Tekram P6B40D-A5 Motherboard, with a BIOS that NickS patched for me to support > 137GB hard drives and all works great.. I'd like to up the FSB to 124 or 133Mhz, and I think my memory and AGP cards will handle it, but I know my PCI cards won't. The BIOS doesn't have a way to change the FSB / PCICLK divider, so I'm pretty sure it's at 2/3, which means my PCI bus is running at 44MHZ or so...
Does anyone know what it would take to patch a BIOS to set the PCICLK to 2/4 (1/2) of the FSB clock? I know some later 440BX boards had this ability. TEKRAM hasn't released an update to this BIOS for a long time, so getting any help from them is unlikely..
If I can get this resolved, I should be able to upgrade to Dual PIII-S Tualatins at 1.4Ghz without having to replace the motherboards.
BIOS String - 02/18/2000-i440BX-W83977-2A69KTG9C-00
Thanks very much.
How to change PCI CLK divider?
The CPU clock to PCI ratio is determined by settings in the clock generator chip. Which clock generator chip do you have ?
I seem to remember that there are some utilities around along the lines of PowerTweak which may allow you to play with the settings.
I seem to remember that there are some utilities around along the lines of PowerTweak which may allow you to play with the settings.
Looks something like this:
although the number of pins may vary. Usually very close to the small metal lump which is the crystal oscillator.
Typically ICS or IDT, you can just make out "ICS" on the pic above.
![Image](http://www.esupport.com/techsupport/award/clock%20chip%20next%20to%20clock%20crystal%20ICS%20example%202.jpg)
Typically ICS or IDT, you can just make out "ICS" on the pic above.
Datasheet received....Pins select 66 or 100 MHz, software can set 66.8, 68.5, 75, 83.3, 100, 103, 112 or 133.3 MHz, but the PCI ratio is fixed depending on frequency, depressingly. So you're stuck with
133.3 - 44.43 MHz PCI.
112 - 37.33
103 - 34.33
100 - 33.33
83.3 - 41.66
75.0 - 37.5
68.5 - 34.25
66.8 - 33.4
133.3 - 44.43 MHz PCI.
112 - 37.33
103 - 34.33
100 - 33.33
83.3 - 41.66
75.0 - 37.5
68.5 - 34.25
66.8 - 33.4
Last edited by NickS on Thu Jan 23, 2003 3:48 pm, edited 1 time in total.
Actually, that's exactly what's hanging up. The on-board IDE seems to work just fine (initializes, detects the DVD drive), but the Promise Ultra 100 board doesn't do a thing. I might play around with the slot positions and see what that does, but I'm not hopeful.
I'm thinking about scrapping the whole thing and building a dual 2400+ Athlon system. I'm using this as a Home Theater PC which requires a lot of horsepower to be able to encode a live video stream in real-time, especially with some of the higher quality encoders.
Thanks...
I'm thinking about scrapping the whole thing and building a dual 2400+ Athlon system. I'm using this as a Home Theater PC which requires a lot of horsepower to be able to encode a live video stream in real-time, especially with some of the higher quality encoders.
Thanks...
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- The New Guy
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- Joined: Fri Mar 29, 2002 10:32 pm
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You would have thought by this time some manufacturer would be making a replacement chip that would lock the bus clocks at their proper frequencies...and make them synchronus, or asynchonus, depending on what your motherboard would require. The market would probably not be very big for this though...
Either that, or some hobbyist would design a daughterboard circuit to do this that could be adapted to fit a motherboard...especially for the older boards that could benefit from an increased CPU clock (ie: Socket 7 with 100MHz CPU clock for an AMD K6-2/III+, with synchronus bus clocks)...
Either that, or some hobbyist would design a daughterboard circuit to do this that could be adapted to fit a motherboard...especially for the older boards that could benefit from an increased CPU clock (ie: Socket 7 with 100MHz CPU clock for an AMD K6-2/III+, with synchronus bus clocks)...
Tom's Hardware has a review of the Powerleap adapter which does this allowing you to run 1.4 GHz Celeron in a Slot 1 mobo.
http://www.tomshardware.com/cpu/20030107/slot_1-01.html Also described at http://www.powerleap.com. I usually find by the time you've paid for the adapter you're half way towards buying a new board, but it may be affordable in the USA.
http://www.tomshardware.com/cpu/20030107/slot_1-01.html Also described at http://www.powerleap.com. I usually find by the time you've paid for the adapter you're half way towards buying a new board, but it may be affordable in the USA.