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PPGA vs FCPGA ... a bit confusing

Peter z80.eu

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Apr 21, 2016
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I have a Baby-AT sized (P)PGA (Socket 370) mainboard, it's one of the first of its kind. That means I can only use Mendocino Celeron 300 to 533 MHz CPUs (with 2 volts Vcore).
Are there any other options I did not have discovered yet? Would like to use a Celeron 533A (Coppermine) CPU, because of the very low power consumption...

Added later: Something like http://krick.3feetunder.com/370mod/ would be interesting, but so far I am a bit afraid destroying the socket (removing the grounded pin AM2).
 
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The difference between a PPGA and FCPGA CPU is the way the CPU core is mounted in the package.

PPGA CPUs have their core orientated upwards, where the top of the die faces the CPU heatsink.

FCPGA CPUs have their core flipped upside down so the top of the die faces the motherboard and the bottom faces the CPU heatsink. They also don't use bond wires, and are mounted directly to the chip carrier.

Intel did this to improve heat transfer in the faster Coppermine CPUs. But they also changed the bus and pinout slightly, making it incompatible with older S370 boards.

If your board was never intended to run Coppermine Celerons, it won't. The bus speed, vcore, socket pinout and bus protocol are all slightly different. There might be a fancy interposer out there somewhere that allows it, but I would not risk damaging an old board like that just because you want lower power consumption.
 
The difference between a PPGA and FCPGA CPU is the way the CPU core is mounted in the package.

PPGA CPUs have their core orientated upwards, where the top of the die faces the CPU heatsink.

FCPGA CPUs have their core flipped upside down so the top of the die faces the motherboard and the bottom faces the CPU heatsink. They also don't use bond wires, and are mounted directly to the chip carrier.
I thought it was the other way around: PPGA had the core facing downward and FCPGA (literally an acronym for "flip chip pin grid array" with the core being "flipped" over) with the core facing upward to allow for better heat transfer with the CPU heat sink & fan assembly.
 
If the chipset on the board supports a 100mhz bus than I could see a rationale for hacking it for Coppermine CPUs, but I agree it seems kind of pointless just for power saving.

Back when you could find all the Coppermine CPUs you could ever want in the trash I did kick around the idea of hacking my dual-socket Abit BP6 to support dual P3s instead of Mendocino celerons, instructions for that were floating around, but it seemed like a lot of hassle for at best maybe a 2x performance goose.

(Also, by the time the appropriate Coppermine CPUs were showing up in the trash they were usually already in technically better motherboards… although a *lot* of dual P3 boards for Coppermines used these Serverworks chipsets with only PCI/PCI-X slots, no AGP. Kind of a bummer for a desktop.)
 
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although a *lot* of dual P3 boards for Coppermines used these Serverworks chipsets with only PCI/PCI-X slots, no AGP. Kind of a bummer for a desktop.)

There were quite a few dual PIII boards with AGP slots. Super Micro had several, two being the P6DBE (dual slot 1) and the P3TDDR (dual 370). I have both of these boards.
 
There were quite a few dual PIII boards with AGP slots. Super Micro had several, two being the P6DBE (dual slot 1) and the P3TDDR (dual 370). I have both of these boards.

Most of the garbage cans I frequented had server equipment in them, and those ServerWorks boards were king. Especially when the PIII went to a 133mhz bus, because Intel really dropped the ball when it came to 133mhz-capable chipsets and nobody in their right mind (or at least with enough money to have agency) trusted Via.
 
I run a Supermicro P6DGE with dual slot-1 SL4BS CPUs on a 440GX chipset overclocked to 120MHz; IDE-to-SATA converter. No problems after 4 years. I the the CPUs were out of an IBM server.
 
Most of the garbage cans I frequented had server equipment in them, and those ServerWorks boards were king. Especially when the PIII went to a 133mhz bus, because Intel really dropped the ball when it came to 133mhz-capable chipsets and nobody in their right mind (or at least with enough money to have agency) trusted Via.

While VIA did have their share of crappy chipsets (8237SB comes to mind), the Apollo 266 used in the P3TDDE and several other boards was rock stable. I've had mine since 2002 and it was a workhorse for almost a decade before it was retired from active service.
 
Just to add to the info here, I believe there were some upgrade adapters like the PowerLeap Neo S370 and PowerLeap PRO/II that were PPGA to FCPGA interposers. The unfortunate reality is that these adapters are relatively hard to find, but there are some Lin Lin adapters out there that pop-up now and again and I *think* those can do FCPGA->PPGA. They definitely support FCPGA2->FCPGA and mention Coppermine-based CPUs on "old mainboards," whatever that means. It's a bit ambiguous, unfortunately.

VIA chipsets are hit and miss for PIII stuff to an extent. VIA Apollo Pro 133A (694X) is pretty decent. It supports 133MHz FSB, AGP 4x, AGP Fast Writes, and a few other nice features. Its sibling, the 694T, includes Tualatin support but eschews PPGA Celeron support. Both are moderately fast chipsets, on par with 440BX at 100MHz. With CL2 RAM and some tweaks, they're really pretty good. They offer native ISA, unlike Intel's i820, and don't need RAMBUS, also unlike i820; that's kind of a win right there. The main downsides to the 694X/T setups are that some boards don't have memory interleaving options in the BIOS and require a utility to enable such in Windows, but on those boards DOS performance is still mediocre. Apollo Pro 266 is awesome, but lacks ISA. However, its DDR support is welcome, and Apollo Pro 266T with Tualatin support is probably the best you can get, bar SiS635T on the one board that has it.
 
There were quite a few dual PIII boards with AGP slots. Super Micro had several, two being the P6DBE (dual slot 1) and the P3TDDR (dual 370). I have both of these boards.

The dual Slot 1 Supermicro boards are super solid. I had a very hard time letting go of my stack of NIB P6DBE boards when I downsized. Beautiful to look at as well.



 
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