Can you under-clock?

[jdesan]

I have a P lll 850 that I want to use on a M/B that only has a multiplier setting up to 8. I don't think there are any more BIOS updates for this board because it has been discontinued because of the Intel MTH issue. The board's system bus will be set at 100 mhz. If I use the setting of 8 will it still boot but only run the Proc. at 800 mhz? Any other considerations?

I'm going to try it but just thought I'd ask. This board has been a pain to get working and I continue to try and use it for some/any system before dumping it. I got a good deal on this Proc. so I'd like to make it work in this board VS getting another board. Getting case tomorrow.

M/B Gigabyte GA 6CXC-1 i820 chipset.

[Randy_tx]

In most instances you can underclock with out a problem. I have seen as much as 150 mhz underclock work fine.

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"As hard as a rock & dumb as a brick"...Windows CEMeNT

[Randy_tx]

On second thought, the PIII might have the clock locked both upward and downward (I dont really know)...but, it wont hurt a thing to try it @ the 8 setting! http://www.PCGuide.com/ubb/biggrin.gif

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"As hard as a rock & dumb as a brick"...Windows CEMeNT

[mjc]

If you can set the voltage correctly and the chip is locked wouldn't come out 100MHz x 8.5 = 850Mhz?

Can you set the voltages in BIOS or is it just jumper settings. The more control for the voltage the more likely you would be to succeed with that chip.

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mjc
To ME or NOT to ME....

[Randy_tx]

Hello mjc...........his initial post said that the highest multiplier he has is 8 ! The core voltage utilized by a 800 mhz and a 850 mhz PIII are exactly the same ...1.65 volts.

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"As hard as a rock & dumb as a brick"...Windows CEMeNT

[jdesan]

Thanks for the responses guys. I did boot and search for OS. The system shows P lll but that's it. (boot screen ) I just remembered that I did flash this BIOS with the only update they made. I was having trouble when trying to use this board in another system. I now see that there are some missing items in the BIOS vs what the Manual shows. The biggest thing is in the "chipset features setup" The manual has [cpu/pci frequency]
[cpu ratio select]

I now only have [cpu ratio] and the setting is LOCKED ( can't be changed)

I am back to my original problem with this board however. It will only boot if I power on then push reset. If I don't do that then the monitor just clicks off and the system hangs. I only have a floppy and video card installed. I've tried different video cards too. I just can't figure what's making this do this. It did it in two other cases so I figure it's not the power supply. Also tried different ram. I don't get any beep errors just the one beep for memory. I'll go ahead and install the hard drive but I know the problem will still be there. The BIOS update did help some as before the update It would take about 20 trys to get it to post. At least now I can power on and after a minute hit the reset and it posts. But I'm out of Ideas as far as getting a normal post etc.

By the way, since my BIOS now says the ratio is locked and there is no setting for changing it, is it safe to assume the BIOS update allowed for faster processors? I'm going to load an OS and see of the Proc. is reported correctly. Thanks again and please let me know if you guys have any more ideas on how to get this to POST correctly.

John DeSantis

[Randy_tx]

Does it post as a 850 mhz? If so, the bios update allowed for the faster clock required for that chip (that would ONLY be possible if you have a jumperless Mobo regarding clock speeds).

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"As hard as a rock & dumb as a brick"...Windows CEMeNT

[jdesan]

I finally got the OS loaded and also the Chipset drivers. It does show 850 mhz during startup so I guess the Bios update did allow for this Processor to be run. It's not a jumperless M/B. The only setting on the board is CPU speed setup. It allows you to select the system bus speed and then states that cpu frequency is controlled by BIOS. I'm set for 100mhz which is correct for this processor and also the memory will only run there as even though the board is capable of higher settings Anand tech says the MTH controller will knock down PC 133 memory to 100 anyway. So, I continue to try and find out why I can't post normally. I temporarily removed the normal reset cable and instead the sleep button cable to the reset pins. I did this because the sleep switch is larger and not recessed and makes it easier for now.

[mjc]

Sorry I deleted a part of my post, what I was trying to get to was if the chip is locked doesn't it just ignore the BIOS setting. I can set my multiplier to 2x in BIOS and my 500MHz Cceleron still post as 500Mhz.

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mjc
To ME or NOT to ME....

[jdesan]

Originally posted by mjc:
Sorry I deleted a part of my post, what I was trying to get to was if the chip is locked doesn't it just ignore the BIOS setting. I can set my multiplier to 2x in BIOS and my 500MHz Cceleron still post as 500Mhz.



Yes I guess it would be ignored by the BIOS. But as I said, this BIOS is a bit different than the original which had settings as I described in my previous post. Moving on to my boot problems, I'm not sure what happened because I was trying slot of things but right now I'm booting up normally. In fact it boots quickly and everything is really running well. Wish I knew what I did to correct for this but still have to see if it lasts.

thanks

[Randy_tx]

I assure you, if the cpu posts up @ 850 mhz, then the bios update provided for the higher multiplier (8.5) in your bios!! If you tried to set the BUS speed at 133 mhz, it would sink like the Titanic.

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"As hard as a rock & dumb as a brick"...Windows CEMeNT

[Paleo Pete]

Have you tried:
1. Different video card.
2. Bare bones system...motherboard, CPU, RAM video card, Keyboard. If it doesn't POST, you narrow down which hardware to check.
3. If it's and AGP video, check the settings in BIOS, especially the AGP Aperture setting. 64MB usually is supposed to work best for most cards.


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Eagles may soar, but weasels don't get sucked into jet engines!
Note: Please post your questions on the forums, not in my email.

Computer Information Links (http://www.geocities.com/paleopete/)

[jdesan]

Originally posted by Paleo Pete:
Have you tried:
1. Different video card.
2. Bare bones system...motherboard, CPU, RAM video card, Keyboard. If it doesn't POST, you narrow down which hardware to check.
3. If it's and AGP video, check the settings in BIOS, especially the AGP Aperture setting. 64MB usually is supposed to work best for most cards.




Thanks, and yes, I had tried all of that. You may have missed my earlier post but since yesterday Morining it has been starting normally and running well. Not sure what I did or what changed but as I said in my previous post, I had tried this board in 3 different cases and a variety of hardware. Before I could not even get to the BIOS. I would hit the Power button and the monitor would click on ( staus light went from yellow to green ) the hardrive would start to access but then the monitor would seem to loose it's signal and click off to yeallow ( standby I guess ) This last case did the same thing but if I hit the reset it would post. I had to do that each time. I continued to fool with BIOS settings and all of the sudden it started working normally. As I said, not sure what fixed it or if it will last but I'm hoping. Thanks again.

PS does anyone know where I can get an explanation on System Management Bus, ACPI, DMI etc. I'm really fuzzy on this stuff. Are all these related to Power management and the ability to control the systems by an IT person. Do we need this stuff on home computers?