RetroPCCupboard wrote on 2026-11-01, 18:17:

Nexxen wrote on 2026-11-01, 16:57:

Is the Pentium a socket 4?
Full tower has P-II and P-III stickers, it was upgraded. My guess is 500MHz.

Looks to be socket 7, but with a Pentium Overdrive in it? Not heard of that. I thought Pentium overdrives were for upgrading 486s. Could that be an MMX CPU in a socket that doesn't have dual voltage support?

The attachment 20261101_175953.jpg is no longer available

Well, Pentium Overdrive came in different flavours. All had the purpose of making an upgrade "plug and play" and not having the user to set any jumpers or anything (except maybe for the 486->Pentium version).
It looks like here the laser etched marking in the top left cornor of the image says "200" so it's probably a PODPMT66X200 which is an MMX 200 MHz, with its own on-board regulator, making it highly plausible that it was use because of the board's inability to supply dual voltages.

I did, however believe that socket 7 was always dual voltage? Or was the only difference from socket 5 the extra available multipliers? Anyways, it isn't all unheard of that the physical socket is a socket 7 even the board is only socket 5 specs - it's been a question of avaliability probably.

H3nrik V! wrote on Yesterday, 06:42:

Well, Pentium Overdrive came in different flavours. All had the purpose of making an upgrade "plug and play" and not having the user to set any jumpers or anything (except maybe for the 486->Pentium version).
It looks like here the laser etched marking in the top left cornor of the image says "200" so it's probably a PODPMT66X200 which is an MMX 200 MHz, with its own on-board regulator, making it highly plausible that it was use because of the board's inability to supply dual voltages.

You are correct! At least on it being 200Mhz. Not sure if MMX yet, but I would hope it is. Good news the PC starts and the IBM monitor seems good too. Quite a nice, sharp stable image on it.

Bad news is that although the 1.2Gb HDD is detected it won't boot. Just sits there with flashing cursor.

H3nrik V! wrote on Yesterday, 06:42:

I did, however believe that socket 7 was always dual voltage? Or was the only difference from socket 5 the extra available multipliers? Anyways, it isn't all unheard of that the physical socket is a socket 7 even the board is only socket 5 specs - it's been a question of avaliability probably.

I have a motherboard that is socket 7 and supports only the original Pentium. But there is some kind of socket next to it for changing the VRM. I think putting an appropriate module would allow it to support MMX.

Not "found a PC in a dumpster" but "found in a dumpster PC": a few months ago, I bought a 2013 era super high end watercooled monster PC. Dual 980's, Rampage Extreme IV motherboard, the lot. But the PC was in serious disarray, non functional, leaky watercooling, dead motherboard..., partially disassembled but everything still inside its humongous Corsair 900D case (which is about 4 PC's large, for those not in the know). But I bought it for very little money, basically bought the case and got the rest. While going through the trainwreck inside the case, I found on the bottom not one but two Samsung 512GB SSD's, never installed. In the current economy, that is quite a find: that pair of SSD's would set me back over 300 euros which is about 5 times what I paid for the lot. The PC itself had a 1TB HDD and 128GB Samsung SSD. I think the previous owner wanted to upgrade to the two 512GB SSD's but then noticed the motherboard was dead and kept everything inside waiting for a better day.

I have since traded the wrecked Corsair PC for a working more modern gaming PC, and use one of these SSD's in there without any issue. The other SSD is waiting for another PC.

Nicolas 2000 wrote on Yesterday, 08:12:

Not "found a PC in a dumpster" but "found in a dumpster PC": a few months ago, I bought a 2013 era super high end watercooled monster PC. Dual 980's, Rampage Extreme IV motherboard, the lot. But the PC was in serious disarray, non functional, leaky watercooling, dead motherboard..., partially disassembled but everything still inside its humongous Corsair 900D case (which is about 4 PC's large, for those not in the know). But I bought it for very little money, basically bought the case and got the rest. While going through the trainwreck inside the case, I found on the bottom not one but two Samsung 512GB SSD's, never installed. In the current economy, that is quite a find: that pair of SSD's would set me back over 300 euros which is about 5 times what I paid for the lot. The PC itself had a 1TB HDD and 128GB Samsung SSD. I think the previous owner wanted to upgrade to the two 512GB SSD's but then noticed the motherboard was dead and kept everything inside waiting for a better day.

I have since traded the wrecked Corsair PC for a working more modern gaming PC, and use one of these SSD's in there without any issue. The other SSD is waiting for another PC.

Wow, that's one of the occasions making "risking a wreck" worth one's time. Kudos!

Even without the SSD's it already was a good deal, especially how I've been able to trade it afterwards. But those SSD's are a huge cherry on top. Especially since I'm not particularly stoked on spending money on something as mundane as an SSD.

Also, it taught me that I don't ever want to bother with a custom loop PC. AIO, maybe. But I love my air cooled stuff so much more after that experience. Just being able to get in there, swap stuff, and not think about it.

RetroPCCupboard wrote on Yesterday, 07:32:

You are correct! At least on it being 200Mhz. Not sure if MMX yet, but I would hope it is. Good news the PC starts and the IBM […]
Show full quote

H3nrik V! wrote on Yesterday, 06:42:

Well, Pentium Overdrive came in different flavours. All had the purpose of making an upgrade "plug and play" and not having the user to set any jumpers or anything (except maybe for the 486->Pentium version).
It looks like here the laser etched marking in the top left cornor of the image says "200" so it's probably a PODPMT66X200 which is an MMX 200 MHz, with its own on-board regulator, making it highly plausible that it was use because of the board's inability to supply dual voltages.

You are correct! At least on it being 200Mhz. Not sure if MMX yet, but I would hope it is. Good news the PC starts and the IBM monitor seems good too. Quite a nice, sharp stable image on it.

The attachment 20261102_070742.jpg is no longer available

Bad news is that although the 1.2Gb HDD is detected it won't boot. Just sits there with flashing cursor.

H3nrik V! wrote on Yesterday, 06:42:

I did, however believe that socket 7 was always dual voltage? Or was the only difference from socket 5 the extra available multipliers? Anyways, it isn't all unheard of that the physical socket is a socket 7 even the board is only socket 5 specs - it's been a question of avaliability probably.

I have a motherboard that is socket 7 and supports only the original Pentium. But there is some kind of socket next to it for changing the VRM. I think putting an appropriate module would allow it to support MMX.

There was some early socket 7 and this looks like that flavor, with probably 440FX ,that officially maxed out at 166, due to not supplying motherboard jumpers to go further and often having a linear regulator that was maxed out with the amps a 166 drew. Thus the plug and play type P200 overdrives were set up to not need jumpering and use less than a regular P200 worth of power from the socket. Sometimes you can avoid the need to source a usually expensive overdrive for such systems by adding extreme cooling to the regulator, or replacing it if a sub can be figured, and either adding missing jumper block on board or hardwiring the socket for the multiplier to run a regular P200. However, usually not worth it on an FX that doesn't have pipeline burst cache, it's already struggling to feed a P133 or so.

BitWrangler wrote on Yesterday, 13:45:

There was some early socket 7 and this looks like that flavor, with probably 440FX ,that officially maxed out at 166, due to not supplying motherboard jumpers to go further and often having a linear regulator that was maxed out with the amps a 166 drew.

Yep, you are right. It is 430fx Chipset (I assume you meant 430 rather than 440).

BitWrangler wrote on Yesterday, 13:45:

However, usually not worth it on an FX that doesn't have pipeline burst cache, it's already struggling to feed a P133 or so.

I wasn't aware of the cache difference. Seems that you are right again that pipeline cache makes a big difference

So the other machine has a 440BX motherboard (Gigabyte GA-686BX) and 550Mhz Pentium III:

Also inside is:
- Intel i740 AGP graphics card (Asus)
- PCI WinTV Tuner
- ISA SCSII Card
- Soundblaster 16 (CT2290 - one of my preferred models)
- Modem card

I haven't yet powered it on, as I don't trust the PSU. I don't want to risk these components so will have to put in another PSU. I am excited to try out the GPU. I haven't had my hands on one before. I know it's not a fast card though. Somewhere around Riva 128 performance I think.

I believe this was the computer my co-worker had, and I added some RAM, the Evergreen/Winchip CPU and installed Win98. I can't recall now if I was able to get the original soundcard/optical drive to work or if I also had him upgrade to an IDE optical drive.

Repo Man11 wrote on Today, 01:00:

I believe this was the computer my co-worker had, and I added some RAM, the Evergreen/Winchip CPU and installed Win98. I can't recall now if I was able to get the original soundcard/optical drive to work or if I also had him upgrade to an IDE optical drive.

Certainly looks very similar to the one I got. I am not sure what to do about the CPU now.

If the Overdrive is indeed wasted in this machine due to no pipeline burst cache, then maybe I should downgrade it.

I have pizza box style HP machine that currently has a non-MMX pentium 150mhz. I have seen conflicting info on whether the HP is 430FX or 430HX. I think it does support pipeline burst COAST module but I think not one installed currently. Maybe could swap the CPUs. I will have to dig out the machine to actually see what's inside. It is a Vectra VL 5/100.

BitWrangler wrote on Yesterday, 13:45:

RetroPCCupboard wrote on Yesterday, 07:32:

You are correct! At least on it being 200Mhz. Not sure if MMX yet, but I would hope it is. Good news the PC starts and the IBM […]
Show full quote

H3nrik V! wrote on Yesterday, 06:42:

Well, Pentium Overdrive came in different flavours. All had the purpose of making an upgrade "plug and play" and not having the user to set any jumpers or anything (except maybe for the 486->Pentium version).
It looks like here the laser etched marking in the top left cornor of the image says "200" so it's probably a PODPMT66X200 which is an MMX 200 MHz, with its own on-board regulator, making it highly plausible that it was use because of the board's inability to supply dual voltages.

You are correct! At least on it being 200Mhz. Not sure if MMX yet, but I would hope it is. Good news the PC starts and the IBM monitor seems good too. Quite a nice, sharp stable image on it.

The attachment 20261102_070742.jpg is no longer available

Bad news is that although the 1.2Gb HDD is detected it won't boot. Just sits there with flashing cursor.

H3nrik V! wrote on Yesterday, 06:42:

I did, however believe that socket 7 was always dual voltage? Or was the only difference from socket 5 the extra available multipliers? Anyways, it isn't all unheard of that the physical socket is a socket 7 even the board is only socket 5 specs - it's been a question of avaliability probably.

I have a motherboard that is socket 7 and supports only the original Pentium. But there is some kind of socket next to it for changing the VRM. I think putting an appropriate module would allow it to support MMX.

There was some early socket 7 and this looks like that flavor, with probably 440FX ,that officially maxed out at 166, due to not supplying motherboard jumpers to go further and often having a linear regulator that was maxed out with the amps a 166 drew. Thus the plug and play type P200 overdrives were set up to not need jumpering and use less than a regular P200 worth of power from the socket. Sometimes you can avoid the need to source a usually expensive overdrive for such systems by adding extreme cooling to the regulator, or replacing it if a sub can be figured, and either adding missing jumper block on board or hardwiring the socket for the multiplier to run a regular P200. However, usually not worth it on an FX that doesn't have pipeline burst cache, it's already struggling to feed a P133 or so.

Well, as far as I've been able to find out, a 200 MHz Overdrive is always an MMX.

RetroPCCupboard wrote on Yesterday, 21:46:

Yep, you are right. It is 430fx Chipset (I assume you meant 430 rather than 440). […]
Show full quote

BitWrangler wrote on Yesterday, 13:45:

There was some early socket 7 and this looks like that flavor, with probably 440FX ,that officially maxed out at 166, due to not supplying motherboard jumpers to go further and often having a linear regulator that was maxed out with the amps a 166 drew.

Yep, you are right. It is 430fx Chipset (I assume you meant 430 rather than 440).

BitWrangler wrote on Yesterday, 13:45:

However, usually not worth it on an FX that doesn't have pipeline burst cache, it's already struggling to feed a P133 or so.

I wasn't aware of the cache difference. Seems that you are right again that pipeline cache makes a big difference

There's a great article on cache here:

https://dependency-injection.com/intel-430fx- … riton-l2-cache/

I have a similar motherboard with 256kb L2 cache on the motherboard. We did a quick experiment with just adding a 256kb COAST module, but it still reported 256kb, not 512kb. Is it correct that these systems use either on board L2, or COAST L2, but can't use both at the same time?

Nicolas 2000 wrote on Today, 08:40:

I have a similar motherboard with 256kb L2 cache on the motherboard. We did a quick experiment with just adding a 256kb COAST module, but it still reported 256kb, not 512kb. Is it correct that these systems use either on board L2, or COAST L2, but can't use both at the same time?

Honestly, I would be surprised if they could use both simultaneously, as it is very different ways of operating as far as I understand ..

Nicolas 2000 wrote on Today, 08:40:

I have a similar motherboard with 256kb L2 cache on the motherboard. We did a quick experiment with just adding a 256kb COAST module, but it still reported 256kb, not 512kb. Is it correct that these systems use either on board L2, or COAST L2, but can't use both at the same time?

Its one or the other, when you plug the COAST in the onboard cache gets disabled by the chipset. I cant recall ever seeing it work in any other fashion. I'm not an expert on how these older chipsets worked but I would take an educated guess that the chipset can only address one or the other internally and cannot combine the two.

I think you're both correct, it sounds logical and it corresponded to our experience. But we had the 256kb COAST module laying around so we might as well try. Alas, no shortcut to the 512kb lifestyle.

Nicolas 2000 wrote on Today, 13:14:

I think you're both correct, it sounds logical and it corresponded to our experience. But we had the 256kb COAST module laying around so we might as well try. Alas, no shortcut to the 512kb lifestyle.

The COAST should be faster than the onboard cache, worth testing to find out.

RetroPCCupboard wrote on Today, 08:00:

I have seen conflicting info on whether the HP

PB

RetroPCCupboard wrote on Today, 08:00:

is 430FX or 430HX. I think it does support pipeline burst COAST module

Doesnt. Packard Bell was PPCHIPS level of quality very good reason why packard bells sucked

Nicolas 2000 wrote on Today, 08:40:

I have a similar motherboard with 256kb L2 cache on the motherboard. We did a quick experiment with just adding a 256kb COAST module, but it still reported 256kb, not 512kb. Is it correct that these systems use either on board L2, or COAST L2, but can't use both at the same time?

there is no "these systems", it depends on case to case basis. Is cache added of same type? Was mobo engineered to sum them?
ctrl-alt-rees https://www.youtube.com/watch?v=SqWkACvpne8 shows a case of 430VX allowing summing up PB L2 https://theretroweb.com/motherboards/s/msi-ms-5129-tr5 tldr only worth it for Quake as Quake was late enough to not fit in 256KB L2. Quake was before people started writing cache aware algorithms, meaning it scales almost linearly all the way to 2MB of L2 and is very ram BW sensitive.

Interesting!

I can no longer test it as I did not buy the COAST module. I used to play Quake on a P200MMX with 512kb L2 when I was a kid, now I have a P200MMX with 256kb so that should be slower. Not too relevant as these days i play GLQuake on a P3.

H3nrik V! wrote on Yesterday, 06:42:

[...]

I did, however believe that socket 7 was always dual voltage? Or was the only difference from socket 5 the extra available multipliers? Anyways, it isn't all unheard of that the physical socket is a socket 7 even the board is only socket 5 specs - it's been a question of avaliability probably.

Socket 7 has dual voltage planes for Vcore and Vio, but it does not require a motherboard to be able to deliver something under 3.2V on the Vcore plane. It also specifies higher permitted currents, which are needed to run say a P200 in-spec (even disregarding the BF1 multiplier jumper that you also need)

RetroPCCupboard wrote on Today, 08:00:

[...]

Certainly looks very similar to the one I got.

Same case but different guts. You have a system with a PB640 (=Intel OEM board) with i430FX chipset, so it's from after January 1995; the one Repo Man11 posted dates to 1994 so will have an older motherboard with different chipset (probably Wildcat or Hillary with i430NX). Doesn't hugely change the situation though, apart from offering worse performance - the boost of the i430FX, even with async cache, was huge.

I am not sure what to do about the CPU now.

If the Overdrive is indeed wasted in this machine due to no pipeline burst cache, then maybe I should downgrade it.

I have pizza box style HP machine that currently has a non-MMX pentium 150mhz. I have seen conflicting info on whether the HP is 430FX or 430HX. I think it does support pipeline burst COAST module but I think not one installed currently. Maybe could swap the CPUs. I will have to dig out the machine to actually see what's inside. It is a Vectra VL 5/100.

"Wasted" is a big word. Performance would be a good deal better with PLB cache, but the extra L1 cache of a Pentium MMX still helps, as do the extra MHz regardless of whether it's MMX or not.

I'd check what the exact situation is with the Vectra:
- it has a COAST slot; what cache (if any) is onboard?
- does it have a VRM to support dual-voltage CPUs?

If it has PLB on the board already (probably 256kB in that case), you can get the full benefit without a COAST stick, but if it has a VRM onboard you might as well just get a regular MMX CPU and leave the overdrive in the PB (if you want to keep both systems).

Trashbytes wrote on Today, 13:05:

[...]

Its one or the other, when you plug the COAST in the onboard cache gets disabled by the chipset. I cant recall ever seeing it work in any other fashion. I'm not an expert on how these older chipsets worked but I would take an educated guess that the chipset can only address one or the other internally and cannot combine the two.

That's definitely true if they use different types of cache (async vs PLB), but I'm pretty sure if they're both PLB they can both be used - and if there's a tag RAM chip on the COAST it can participate as well. Take the Asus P55T2P4 - it was shipped with 0, 256 or 512kB of PLB L2 cache; if shipped with 256kB of PLB, you could upgrade to 512kB by adding a 256kB COAST module, and if that module had a tag RAM onboard, it could increase cacheable area from 64MB to 512MB.