I had a similar strange issue with an EPOX nForce 2 motherboard. But my issue stemmed from the fact that I was using an AthlonXP mobile chip and the board just didn't support it, but at the listed FSB, the system ran at literally half speed.

This is yet another reason why I don't trust old PSUs as far as my 1-year-old could throw them.

I recently tested a nice stack of around 10 older ATX PSUs including some that came from OEM systems.

Out of those, there were multiple that the voltages were waaaay off. A few were even completely missing certain voltage rails (not -5v... duh) and one or two would blink on/off certain voltage rails.

From that stack, I ended up keeping I think 2 that actually had correct voltages. One was even spot on on every single voltage. It was a Thermaltake which really surprised me as I have not really had good luck with them in the past.

I will only use newer PSUs that are at least really rated 80+ Bronze and are from a reputable mfg such as Seasonic unless I am using a case that only supports a weird form factor PSU. I've even though about swapping the internals of those types of PSUs with good internals.

Back in the day I worked at a computer store.. this was around the year 2000. I purchased one of the higher priced and higher power PSUs we were selling at the time. First time I powered it up, it shot flames out the back of it.

The cheaper ones were crappy brands such as Deer which weighed almost nothing.

The uATX PSUs of the time that were used in such systems as eMachines we sold butt-loads of replacement PSUs for. I forget the brand we sold, but it was a higher end brand.

Been working with this stuff for over 30 years now (started when I was 12). The newer PSUs are infinitely better than almost all the older PSUs and much safer to use as well. Normally you don't have to worry about a PSU taking out multiple items inside your case if it blows. Not so with those older PSUs.

Plus you have how many year old capacitors and other components in those ancient PSUs? The capacitors should pretty much all be replaced at the very least. If I have a PSU open, I also check for cracked solder joints and anything else that doesn't look right. I don't really do that much anymore unless it is a really nice PSU that I definitely want to use. Mostly IU will just salvage the fans from them and then scrap the rest.

Not worth my time or money to gamble with this old stuff that may or may not work long term and if it does die, has a decent chance to take out components with it.

Plus the newer PSUs are way more efficient (60-70% for older PSUs and around 80-90+ % for newer PSUs) and have way cleaner power output which will also help the rest of the components last longer and run cooler.

drosse1meyer wrote on 2021-08-14, 00:11:

Hello all […]
Show full quote

Hello all

Ran into something today which was interesting.... Specifically,I have a socket 370 board, 815 chipset, testing 4 different Pentium 3 CPUs.

• 100 FSB: 500 , 1000 mhz
• 133 FSB: 733 , 866 mhz

Oddly, when I install a 133 FSB CPU, it will run at about 3/4 speed, or at least reports itself as. For example, the 866 posts as 650 MHz...and the 733 -> 550 MHz...

This really stumped me for a while as the 100 MHz FSB processors would post at their correct speeds.

Eventually I tried swapping the PSU for the hell of it and, guess what? The two problem CPUs suddenly ran at full clock.

I've never seen this before, has anyone else? (at the very least this may help someone troubleshoot in the future.)

Thank you

Why do you assume that this is a PSU problem? (it's definitely not!). Even though swapping the PSU apparently "fixed" the problem, I'm thinking this is more of a coincidence than anything else.
It just seems like a BIOS issue (the FSB defaults to 100 MHz), so naturally the CPUs that require a 133 MHz FSB, will be downclocked (All P3s have a factory locked multiplier, so the effective speed will be the CPU's multiplier x FSB frequency).
Check your motherboard's manual to see how you can force a 133 MHz FSB.

bloodem wrote on 2021-08-14, 05:46:

Why do you assume that this is a PSU problem? (it's definitely not!). Even though swapping the PSU apparently "fixed" the proble […]
Show full quote

drosse1meyer wrote on 2021-08-14, 00:11:

Hello all […]
Show full quote

Hello all

Ran into something today which was interesting.... Specifically,I have a socket 370 board, 815 chipset, testing 4 different Pentium 3 CPUs.

• 100 FSB: 500 , 1000 mhz
• 133 FSB: 733 , 866 mhz

Oddly, when I install a 133 FSB CPU, it will run at about 3/4 speed, or at least reports itself as. For example, the 866 posts as 650 MHz...and the 733 -> 550 MHz...

This really stumped me for a while as the 100 MHz FSB processors would post at their correct speeds.

Eventually I tried swapping the PSU for the hell of it and, guess what? The two problem CPUs suddenly ran at full clock.

I've never seen this before, has anyone else? (at the very least this may help someone troubleshoot in the future.)

Thank you

Why do you assume that this is a PSU problem? (it's definitely not!). Even though swapping the PSU apparently "fixed" the problem, I'm thinking this is more of a coincidence than anything else.
It just seems like a BIOS issue (the FSB defaults to 100 MHz), so naturally the CPUs that require a 133 MHz FSB, will be downclocked (All P3s have a factory locked multiplier, so the effective speed will be the CPU's multiplier x FSB frequency).
Check your motherboard's manual to see how you can force a 133 MHz FSB.

Well, a few more things

1 - This an intel/gateway OEM board. There are basically no jumpers or bios settings to configure - it's all auto
2 - Yeah I know about the locked multiplier but didn't think to look them up and do the math on these various processors, it seems to explains the resulting speeds.
The 733 has a 5x multiplier, that would would give 500 MHz if forced to 100 mhz FSB. (If you look at the pic, i'm using PC133 RAM. The POST screen doesn't tell me what FSB is being used. I could try a boot disk or other utils to get this info but was just doing this quick yesterday.) What's odd is that because the FSB is being forced to 100 mhz one may think that slower memory may actually work in this setup. However this is not the case and it just gives a memory beep code, so one can conclude that whatever's happening with the FSB being 'downclocked' is after the POST procedure checks the RAM and CPU speeds.
3 - This board apparently won't let you mix PC133 RAM with a CPU using 100 FSB even though it's 'all auto'. From my past experience, faster RAM should fallback and run fine with this config, unless of course we are just limited by the vendors auto implementation. For example, installing PC133 with a 500 mhz chip results in memory beep code.

Hopefully this sheds a bit more light on whats going on, but clearly the combination of that specific PSU and motherboard is forcing 100 FSB incorrectly at times. I have no other socket370 board I can test this with however and all I can report is that installing a different PSU made it work correctly with all configurations.

cyclone3d wrote on 2021-08-14, 05:29:

This is yet another reason why I don't trust old PSUs as far as my 1-year-old could throw them. […]
Show full quote

This is yet another reason why I don't trust old PSUs as far as my 1-year-old could throw them.

I recently tested a nice stack of around 10 older ATX PSUs including some that came from OEM systems.

Out of those, there were multiple that the voltages were waaaay off. A few were even completely missing certain voltage rails (not -5v... duh) and one or two would blink on/off certain voltage rails.

From that stack, I ended up keeping I think 2 that actually had correct voltages. One was even spot on on every single voltage. It was a Thermaltake which really surprised me as I have not really had good luck with them in the past.

I will only use newer PSUs that are at least really rated 80+ Bronze and are from a reputable mfg such as Seasonic unless I am using a case that only supports a weird form factor PSU. I've even though about swapping the internals of those types of PSUs with good internals.

Back in the day I worked at a computer store.. this was around the year 2000. I purchased one of the higher priced and higher power PSUs we were selling at the time. First time I powered it up, it shot flames out the back of it.

The cheaper ones were crappy brands such as Deer which weighed almost nothing.

The uATX PSUs of the time that were used in such systems as eMachines we sold butt-loads of replacement PSUs for. I forget the brand we sold, but it was a higher end brand.

Been working with this stuff for over 30 years now (started when I was 12). The newer PSUs are infinitely better than almost all the older PSUs and much safer to use as well. Normally you don't have to worry about a PSU taking out multiple items inside your case if it blows. Not so with those older PSUs.

Plus you have how many year old capacitors and other components in those ancient PSUs? The capacitors should pretty much all be replaced at the very least. If I have a PSU open, I also check for cracked solder joints and anything else that doesn't look right. I don't really do that much anymore unless it is a really nice PSU that I definitely want to use. Mostly IU will just salvage the fans from them and then scrap the rest.

Not worth my time or money to gamble with this old stuff that may or may not work long term and if it does die, has a decent chance to take out components with it.

Plus the newer PSUs are way more efficient (60-70% for older PSUs and around 80-90+ % for newer PSUs) and have way cleaner power output which will also help the rest of the components last longer and run cooler.

Thanks for the reply. Yeah its weird because the bogus PSU works fine with a newer board+CPU (e.g. nforce4 based 939). I would think that if anything, more power hungry or modern devices would cause issues, but who knows. I did open these up and check caps and stuff a while back and everything looked fine.

Ironically enough, the brand that brought everything back to life is a Thermaltake. 🤣.

Guess I should go shopping for a good additional PSU and toss this generic one.

drosse1meyer wrote on 2021-08-14, 12:52:

1 - This an intel/gateway OEM board. There are basically no jumpers or bios settings to configure - it's all auto

I have a board like that used Slot 1 with an Intel 440BX chipset and was disappointed with it due to the only ISA slot on my board didn't work very well on any sound card no matter what and the capacitors around the CPU slot making it difficult to install some custom coolers. Eventually replaced it with an ASUS one.

Pentium III CPUs are usually multiplier locked.

Edit: Removed misleading statement regarding the FSB, I though that it was related to the Slot 1 pins.

Gmlb256 wrote on 2021-08-14, 16:19:

Pentium III CPUs are both multiplier and FSB locked and couldn't change the FSB thru software in my case.

Huh? The FSB frequency is set by the motherboard and any late Intel Pentium 3 CPU can comfortably run at 66 / 100 / 133 MHz (maybe even 50 MHz, on motherboards that support it).

bloodem wrote on 2021-08-14, 16:27:

Gmlb256 wrote on 2021-08-14, 16:19:

Pentium III CPUs are both multiplier and FSB locked and couldn't change the FSB thru software in my case.

Huh? The FSB frequency is set by the motherboard and any late Intel Pentium 3 CPU can comfortably run at 66 / 100 / 133 MHz (maybe even 50 MHz, on motherboards that support it).

Well in my experience I only have two Coppermine-based CPU that runs at 100MHz FSB, one which runs at 750MHz and another one at 650MHz. On my ASUS motherboard I couldn't change the FSB through software, however I have a Pentium II CPU that runs at 400 MHz (one of these with the multiplier unlocked) and with this CPU I could set the FSB including 50Mhz in software without any problems.

I admit that I haven't tested setting the FSB manually or thru the BIOS for the Pentium III though, the ASUS board I own is configured by jumpers.

In case anyone doesn't believe me when I'm setting the FSB by software, there is a program written by RayeR which is named SMB that allows to do that without having to reboot or shut down the computer.

Not being able to modify the FSB through third party software like RayeR's utility does not mean that the CPU has a "locked FSB", that's just a wrong statement to make. 😀
The FSB frequency is usually controlled either by jumpers, by DIP switches, or through software (BIOS) and the CPU has no saying in it. The CPU can request a certain frequency, but the motherboard can force any other frequency, since it controls the clock generator.

RayeR only supports a few clock generators, such as the ICS 9148BF-26, which is found on the Gigabyte GA-6BXC boards.

cyclone3d wrote on 2021-08-14, 05:29:

This is yet another reason why I don't trust old PSUs as far as my 1-year-old could throw them.

I recently tested a nice stack of around 10 older ATX PSUs including some that came from OEM systems.

Out of those, there were multiple that the voltages were waaaay off. A few were even completely missing certain voltage rails (not -5v... duh) and one or two would blink on/off certain voltage rails.

It would help many people if you could recommend good modern PSU models that are also good for old rigs and do not miss any voltage rails.

For comparison specs of a few of my old unused PSUs:
Eurocase 200W - 3.3V - 12A, 5V - 20A, max 120W load on 3.3+5V
- one would have to get 500W PSU to get these poor specs on 3.3V+5V

Eurocase 300W - 3.3V - 14A, 5V - 30A, max 160W load on 3.3V+5V
- need 800W?

Eurocase 350W - 3.3V - 14A, 5V - 30A, max 185W load on 3.3V+5V
- need 1000W?

bloodem wrote on 2021-08-14, 18:16:

RayeR only supports a few clock generators, such as the ICS 9148BF-26, which is found on the Gigabyte GA-6BXC boards.

I'm aware of the limitations of that utility and that the OP has a i815 chipset which doesn't work with it anyway.

Sorry for the misleading statements regarding the FSB.

AlexZ wrote on 2021-08-14, 18:35:

It would help many people if you could recommend good modern PSU models that are also good for old rigs and do not miss any volt […]
Show full quote

cyclone3d wrote on 2021-08-14, 05:29:

This is yet another reason why I don't trust old PSUs as far as my 1-year-old could throw them.

I recently tested a nice stack of around 10 older ATX PSUs including some that came from OEM systems.

Out of those, there were multiple that the voltages were waaaay off. A few were even completely missing certain voltage rails (not -5v... duh) and one or two would blink on/off certain voltage rails.

It would help many people if you could recommend good modern PSU models that are also good for old rigs and do not miss any voltage rails.

For comparison specs of a few of my old unused PSUs:
Eurocase 200W - 3.3V - 12A, 5V - 20A, max 120W load on 3.3+5V
- one would have to get 500W PSU to get these poor specs on 3.3V+5V

Eurocase 300W - 3.3V - 14A, 5V - 30A, max 160W load on 3.3V+5V
- need 800W?

Eurocase 350W - 3.3V - 14A, 5V - 30A, max 185W load on 3.3V+5V
- need 1000W?

Look at Seasonic. I recently looked on their homepage and their new PSUs have decently sized 3.3 and 5v rails.

For a while I was buying the NOS Seasonic PSUs off of eBay in the 350-650w range but the supply of those has dried up. I'll post some specific models once I am in front of my computer.

Also remember to take into account that the old cheap PSUs when new were maybe good for about 1/2 their rated output before they would release the magic smoke or catch on fire.

hardocp.com(no longer exists except for the forums) and jonnyguru.com used to do actual real tests of PSUs and when they would do reviews of cheaply made PSUs, they would have failures across the board and often those PSUs would either just die or die catastrophic deaths.

I only use high-quality modern PSU since older ones are noisy, less efficient and have aging parts. Had one with -5v rails that caused a myriad of issues such as freezing or not being able to POST.

I remember back then that Hardware Secrets also did actual tests of PSU and even tested a generic unbranded one that silently died when attempting to pull 500W out of it. The article about the generic PSU is still there but the images are gone.

Gmlb256 wrote on 2021-08-14, 16:19:

I have a board like that used Slot 1 with an Intel 440BX chipset and was disappointed with it due to the only ISA slot on my boa […]
Show full quote

drosse1meyer wrote on 2021-08-14, 12:52:

1 - This an intel/gateway OEM board. There are basically no jumpers or bios settings to configure - it's all auto

I have a board like that used Slot 1 with an Intel 440BX chipset and was disappointed with it due to the only ISA slot on my board didn't work very well on any sound card no matter what and the capacitors around the CPU slot making it difficult to install some custom coolers. Eventually replaced it with an ASUS one.

Pentium III CPUs are usually multiplier locked.

Edit: Removed misleading statement regarding the FSB, I though that it was related to the Slot 1 pins.

This socket 370 build was intended for pure Windows gaming, so I was going for AGP + PCI and didn't mind it lacking a ISA slot... I was disappointed that it turned out to be a gateway branded board, which also could have been dangerous, but apparently they don't require proprietary PSU. I should have looked up the model but I wasn't really paying attention and trusted the fleabay listing, which just said Intel and lacked any mention of Gateway. That's bad on me. Regardless, I'll keep it for now, it appears to work properly and has plenty of slots and an intel chipset. Will post more about this build and benchmarks as time allows...

cyclone3d wrote on 2021-08-14, 19:18:

AlexZ wrote on 2021-08-14, 18:35:

It would help many people if you could recommend good modern PSU models that are also good for old rigs and do not miss any volt […]
Show full quote

cyclone3d wrote on 2021-08-14, 05:29:

This is yet another reason why I don't trust old PSUs as far as my 1-year-old could throw them.

I recently tested a nice stack of around 10 older ATX PSUs including some that came from OEM systems.

Out of those, there were multiple that the voltages were waaaay off. A few were even completely missing certain voltage rails (not -5v... duh) and one or two would blink on/off certain voltage rails.

It would help many people if you could recommend good modern PSU models that are also good for old rigs and do not miss any voltage rails.

For comparison specs of a few of my old unused PSUs:
Eurocase 200W - 3.3V - 12A, 5V - 20A, max 120W load on 3.3+5V
- one would have to get 500W PSU to get these poor specs on 3.3V+5V

Eurocase 300W - 3.3V - 14A, 5V - 30A, max 160W load on 3.3V+5V
- need 800W?

Eurocase 350W - 3.3V - 14A, 5V - 30A, max 185W load on 3.3V+5V
- need 1000W?

For a while I was buying the NOS Seasonic PSUs off of eBay in the 350-650w range but the supply of those has dried up. I'll post some specific models once I am in front of my computer.

Alright sounds good. FWIW gamersnexus seems to do pretty decent reviews and torture tests of components, let me search around there as well...