knowing how compaq tended to standardize things, I'd be shocked if the PCB was actually different

I bet you could tone out which strap resistors control the multiplier (by going to the BFx pins on the socket) and move them accordingly

Brickpad wrote on 2025-02-07, 03:06:

Hey all, […]
Show full quote

Hey all,

I have a Compaq Prosignia 300 server that I've owned for the last 20+ years and have always wanted to upgrade the original 150MHz Pentium CPU in it to either a non-MMX flavor Pentium 166 or 200. From my understanding, these servers required the entire processor board to be replaced depending on what speed CPU you were upgrading (or downgrading) to. So it seems then that these processor boards are both multiplier and FSB locked. There are no jumpers or DIP switches to adjust to match the installed CPU. Has anyone successfully upgraded to a faster Pentium, or at least an idea how to, or what may need to be removed / replaced on the processor board?

I've attached a photo of a (120MHz) processor board as an example.

Thanks!

Might be worth a read... https://community.hpe.com/t5/proliant-servers … de/td-p/2468247

The Deskpro/XL shares the CPU-board with the Prosignia 300/500 but uses a different bracket.

I tweaked some Deskpro /XL from 90 to 120 MHz years ago by swapping some 0 Ohm SMD-resistors on the CPU board, but was never able to change the clock frequency,
because I never found an original 66MHz CPU board to copy from.
Owning no 120 MHz CPUs I just installed 133 from stock.
Interestingly the QRG lists a 100 MHz as well as a 133 MHZ board for the Deskpro/XL but not for the Prosignias
It might need a closer look at the clock chip datasheet, as these boards do not use swappable oscillators like the ones used on 486 but a programmable clock chip.

Never tried the PPro Board from the Deskpro 6200/XL in my Prosignia 300.
Not sure if the BIOS will accept it, or might damage this rare board.

All good information!

Now, if I remember correctly, the Prosignia only came in 75MHz, 90MHz, 120MHz, and 150MHz flavors, which gave me the thought - What bus speed and multipliers did this / these board(s) support? So, doing a quick back search, these boards must have only supports two bus speeds - 50MHz and 60MHz, and three multipliers - 1.5x, 2x, and 2.5x - It might be easier to boost the FSB to 66MHz, rather than someone altering the board multiplier?

[EDIT]

I should mention that I may have tried installing a 200MHz Pentium Overdrive without success, years ago. Either it didn't boot, or it only ran at 150MHz. Can't remember...

Brickpad wrote on 2025-02-07, 17:35:

All good information! […]
Show full quote

All good information!

Now, if I remember correctly, the Prosignia only came in 75MHz, 90MHz, 120MHz, and 150MHz flavors, which gave me the thought - What bus speed and multipliers did this / these board(s) support? So, doing a quick back search, these boards must have only supports two bus speeds - 50MHz and 60MHz, and three multipliers - 1.5x, 2x, and 2.5x - It might be easier to boost the FSB to 66MHz, rather than someone altering the board multiplier?

[EDIT]

I should mention that I may have tried installing a 200MHz Pentium Overdrive without success, years ago. Either it didn't boot, or it only ran at 150MHz. Can't remember...

I was going to say mount a 233mmx, strap the multipliers to 1.5 and enjoy 210mhz

This system has a Compaq Triflex chipset, right? Iirc that chipset itself was limited to 60MHz FSB. Trying to find sources for that now...

dionb wrote on 2025-02-07, 20:09:

This system has a Compaq Triflex chipset, right? Iirc that chipset itself was limited to 60MHz FSB. Trying to find sources for that now...

Only thing I could find so far was for the older System Pro servers. No mention of the Prosignia 300 using this, although I came across Prosignia 300 with a Celeron board, but that doesn't seem right.

rmay635703 wrote on 2025-02-07, 19:20:

Brickpad wrote on 2025-02-07, 17:35:

All good information! […]
Show full quote

All good information!

Now, if I remember correctly, the Prosignia only came in 75MHz, 90MHz, 120MHz, and 150MHz flavors, which gave me the thought - What bus speed and multipliers did this / these board(s) support? So, doing a quick back search, these boards must have only supports two bus speeds - 50MHz and 60MHz, and three multipliers - 1.5x, 2x, and 2.5x - It might be easier to boost the FSB to 66MHz, rather than someone altering the board multiplier?

[EDIT]

I should mention that I may have tried installing a 200MHz Pentium Overdrive without success, years ago. Either it didn't boot, or it only ran at 150MHz. Can't remember...

I was going to say mount a 233mmx, strap the multipliers to 1.5 and enjoy 210mhz

Probably the best plan there. I don't feel like it's worth taking case screws out for less than 25% boost, never mind paying much. And with a classic with the FSB nailed to 60 best you're gonna do is 180 from a 200 which is like 20%, so go to MMX and 3.5x and get 210, gives you 40% clock plus another "elastic" 20% from bigger cache, depending on how apps use it. This is with running the MMX on the non split voltage, as ppl have been known to do for several years on this CPU at full speed so doing it at 210 should be pretty safe.

Brickpad wrote on 2025-02-08, 17:00:

[...]

Only thing I could find so far was for the older System Pro servers. No mention of the Prosignia 300 using this, although I came across Prosignia 300 with a Celeron board, but that doesn't seem right.

Well the pic in the OP has a couple of Triflex chips in it, so pretty sure about that.

The Triflex chipset was modular and very adaptable, it was used for 486, Pentium and Pentium Pro systems, both server/workstation grade and some more desktop-oriented things (Deskrpro XL series comes to mind). One thing it wasn't was lightning-fast.

The Triflex chipset was used with 66 MHz in the Deskpro/XL, so that might not be the limiting factor.
Systempro uses Flex MP chipset which is not even SMP, but using a dedicated HAL in Win NT.

Not sure why 166 was the fastest CPU-speed availiable from Compaq?
Probably the systems were superseeded by new Deskpro(Desktop) and Proliant (Servers) models, so no processor upgrade were offered for these old systems anymore?

Need to investigate on the ICS clockchip datasheet to find a way to make these run at 33/66 MHz.
Adding the BF Jumper for 3x clockspeed will be the next step.
I remember soldering some 0 Ohm resistors straight to the socket,
but not sure if it was one of these systems?
Just got me some spare CPU boards from storage for these task yesterday.

eisapc wrote on 2025-02-10, 08:31:

The Triflex chipset was used with 66 MHz in the Deskpro/XL, so that might not be the limiting factor.

Not sure why 166 was the fastest CPU-speed availiable from Compaq?

Need to investigate on the ICS clockchip datasheet to find a way to make these run at 33/66 MHz.

In the “classic “ Pentium era very few systems using the original P200 were manufactured.

The chip was moderately rare being a paper tiger to compete with other chip makers (afterthought).

In addition The CPUs shelf life was quite short.

All the above means that it wasn’t readily available in the tray/overdrive market when it was top of the line.

The systems offered with one were pretty much strictly tier 1 name brands and it carried a hefty premium.