VOGONS


First post, by CHiLL72

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There have been a few topics on the CUBX-E and similar mainboards, but I am wondering if anyone has been running a 1.1GHz (100MHz FSB) Pentium III on an ASUS CUBX-E for an extended period of time.
Currently, I have a system with the ASUS CUBX-E, Pentium III 850MHz and my Voodoo 5 5500 AGP. Tonight I went through my stash of Socket 370 CPUs and among them were a couple of SL5QW Pentium III 1.1GHZ processors. As much as I'd like to upgrade my system with one of those CPUs, it will likely put more strain on the mainboard. The TDP of these processors is rated at 33W, where the 850MHz only has a TDP of 22.5W. I am using a decent CPU cooler (Alpha PAL6035).
So I would like to know if I may expect adverse effects of running this higher spec CPU on my mainboard in the medium to long term. Is there anyone who can share their experience with a similar setup?

Waveblaster MIDI boards: https://waveblaster.nl - online now!

Reply 1 of 6, by 2Mourty

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I LOVE this motherboard. I think it is the most stable motherboard I have ever owned. I have a passive powerleap socket adapter and have been running a 1.4ghz Tualatin for years on the board. I think the tdp on it is 32.2W. That is pretty close to 33W.

Reply 2 of 6, by DenizOezmen

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Asus lists the Celeron 1100 as being compatible with the CUBX-E on their support website. According to Intel datasheets, both the Celeron 1100 and the Pentium III 1100 basically have the same maximum ratings (33 W TDP, 22.6W ICC Core, ...). While this seems odd (the Pentium obviously has more L2 cache), this would indicate that the CUBX-E should be able to run the Pentium.

Reply 3 of 6, by auron

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CHiLL72 wrote on 2020-04-28, 20:40:

There have been a few topics on the CUBX-E and similar mainboards, but I am wondering if anyone has been running a 1.1GHz (100MHz FSB) Pentium III on an ASUS CUBX-E for an extended period of time.

have had this exact combination running on and off for years, with an intel cooler, never had any stability issues or cpu temps that seemed worrying. in fact i only just now realized that the p3 1100 is missing from the compatibility page, while the celeron 1100 is on there... not sure what to think of that as they are both are rated for that same 33W TDP.

the 1100 hardlocks voltage at 1.75V minimum which contributes to the big TDP difference, and logically the VRMs will put out more heat. depending on how much you care about that, it could be addressed with extra airflow, either with a back case fan or even better a big 120mm fan with an open setup. one could also check the VRM part numbers and calculate whether they would stay in spec with the faster chip, though i'd be quite surprised if that wasn't the case.

Reply 4 of 6, by CHiLL72

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auron wrote on 2020-04-29, 01:14:
CHiLL72 wrote on 2020-04-28, 20:40:

There have been a few topics on the CUBX-E and similar mainboards, but I am wondering if anyone has been running a 1.1GHz (100MHz FSB) Pentium III on an ASUS CUBX-E for an extended period of time.

have had this exact combination running on and off for years, with an intel cooler, never had any stability issues or cpu temps that seemed worrying. in fact i only just now realized that the p3 1100 is missing from the compatibility page, while the celeron 1100 is on there... not sure what to think of that as they are both are rated for that same 33W TDP.

the 1100 hardlocks voltage at 1.75V minimum which contributes to the big TDP difference, and logically the VRMs will put out more heat. depending on how much you care about that, it could be addressed with extra airflow, either with a back case fan or even better a big 120mm fan with an open setup. one could also check the VRM part numbers and calculate whether they would stay in spec with the faster chip, though i'd be quite surprised if that wasn't the case.

Good point. I already have a casefan pulling air over the CPU and AGP card. Voodoo5 needs to be cool too!

Waveblaster MIDI boards: https://waveblaster.nl - online now!

Reply 5 of 6, by SPBHM

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auron wrote on 2020-04-29, 01:14:
CHiLL72 wrote on 2020-04-28, 20:40:

There have been a few topics on the CUBX-E and similar mainboards, but I am wondering if anyone has been running a 1.1GHz (100MHz FSB) Pentium III on an ASUS CUBX-E for an extended period of time.

have had this exact combination running on and off for years, with an intel cooler, never had any stability issues or cpu temps that seemed worrying. in fact i only just now realized that the p3 1100 is missing from the compatibility page, while the celeron 1100 is on there... not sure what to think of that as they are both are rated for that same 33W TDP.

the 1100 hardlocks voltage at 1.75V minimum which contributes to the big TDP difference, and logically the VRMs will put out more heat. depending on how much you care about that, it could be addressed with extra airflow, either with a back case fan or even better a big 120mm fan with an open setup. one could also check the VRM part numbers and calculate whether they would stay in spec with the faster chip, though i'd be quite surprised if that wasn't the case.

about the voltage 1.75v, is it hardware locked or is it the bios?
from what I noticed the cubx-e simply doesn't allow any undervolt on any CPU?

the bios mod from this thread Modified BIOSes for ASUS P3B-F, P3V4X, CUBX and CUBX-E/L claims it has undervolting support, I wonder if the 1100 can run at 1.70v or something with it
I might have to test it, I actually have this combination (cubx-e and coppermine 1100 p3) since around 2014 but never gave it a proper go, it didn't seem to overheat or anything, at least just using my fingers to touch some components,

Reply 6 of 6, by auron

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no idea, but i remember that my 900 ran at 1.7v on that board.

undervolting could be worth a try if it indeed works on that modded bios, particularily on a chip from 2002-2003, as one would think the manufacturing process matured by that time. the early chips seemed to be running at their limit though, with that originally recalled 1133 supposedly requesting 1.8v.