VOGONS


First post, by Soap

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Completely baffled I am so seeing if I can find some guidance.

i430VX Chipset with a P133s, trying to overclock to P166 or even P200, BIOS identifies CPU as 166MHz and even 200MHz when jumpers are changed which is not an issue.

Confusion for me begins in Windows 95 OSR 2.5 as CPU identifies as 166MHz in BIOS but is identified as 133MHz in CPUz and Everest, CPUid under WInDOS and pure DOS both again it show's as 133MHz.

Basically where am I going wrong?

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Reply 3 of 10, by Cuttoon

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Bios tells you it's a Pentium type CPU that's running at 166 MHz, smarter software tells you it's a CPU whose id tag says "model Intel Pentium 133".
At least that's my guess.

Are you sure you want to run that poor thing at 200 MHz?
I mean, there sure was quite some price discrimination involved in Intel's grading scheme, but 50 % ?
Well, if it works, you're not risking to burn anything of value, if it does behave like a candle at that state.

I like jumpers.

Reply 4 of 10, by Soap

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Cuttoon wrote on 2022-04-19, 12:55:
Bios tells you it's a Pentium type CPU that's running at 166 MHz, smarter software tells you it's a CPU whose id tag says "model […]
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Bios tells you it's a Pentium type CPU that's running at 166 MHz, smarter software tells you it's a CPU whose id tag says "model Intel Pentium 133".
At least that's my guess.

Are you sure you want to run that poor thing at 200 MHz?
I mean, there sure was quite some price discrimination involved in Intel's grading scheme, but 50 % ?
Well, if it works, you're not risking to burn anything of value, if it does behave like a candle at that state.

After a few loops of a synthetic CPU benchmark at 166MHz the heatsink for the CPU is warmish, about to switch back to 133 and compare, may even try 200 again should get I get to bottom of CPUid problem.

Reply 5 of 10, by Soap

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After a few benchmarks of different speeds

P133s (133MHz in BIOS and Windows)

3dmark99Max
967 CPU Marks

SYSinfo (DOS)
CPU Score 420

P166s (166MHz in BIOS and 133MHz Windows)

3dmark99Max
977 CPU Marks

SYSinfo (DOS)
CPU Score 421

P200s (200MHz in BIOS and 100 MHz Windows)

3dmark99Max
752 CPU Marks

SYSinfo (DOS)
CPU Score 316

So well I wonder what the heck is going on?

Reply 6 of 10, by waterbeesje

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To me it looks like it's still running at 133 with the 166 setting and degrades to 100 with the 200 setting. Could you try running out at 100 for the benchmarks?

Maybe there's a multiplier pin the bios detects but the CPU ignores...

Stuck at 10MHz...

Reply 7 of 10, by BitWrangler

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Multipliers recognised by 95% of the P133 production run are just 1.5 and 2x.. you can set 2.5x 3x or 3.5x on the board, but it's still gonna run at 2x or 1.5x unless you got a board that notices and complains. I only left 5% hanging as a maybe on claims that later P133 cores culled from P200 production dies might have been capable, but I've never seen one. I've run P133s at 166 but with bus speed set to 83Mhz, not on multipliers. Some people are gonna wanna use the word "locked" here, but when P133s were new, highers multis were not thought of yet, so saying it's multi locked to a max of 2 is as daft as saying it's DDR4 locked, as in it would support it perfectly but some fuse was blown to stop you.

Unicorn herding operations are proceeding, but all the totes of hens teeth and barrels of rocking horse poop give them plenty of hiding spots.

Reply 8 of 10, by Soap

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BitWrangler wrote on 2022-04-19, 14:32:

Multipliers recognised by 95% of the P133 production run are just 1.5 and 2x.. you can set 2.5x 3x or 3.5x on the board, but it's still gonna run at 2x or 1.5x unless you got a board that notices and complains. I only left 5% hanging as a maybe on claims that later P133 cores culled from P200 production dies might have been capable, but I've never seen one. I've run P133s at 166 but with bus speed set to 83Mhz, not on multipliers. Some people are gonna wanna use the word "locked" here, but when P133s were new, highers multis were not thought of yet, so saying it's multi locked to a max of 2 is as daft as saying it's DDR4 locked, as in it would support it perfectly but some fuse was blown to stop you.

After some digging I found the A04 Bios as I was running the A03, after flashing the CPU tops at 133, if I set to 200 it detects in bios as 133, I select 166 again it detects as 133 in BIOS.

As far as I can tell the multiplier is tied to the CPU as I cannot find a jumper for Multiplier.

Wondering if to get a 166 or a 200 and drop that in as the BIOS clearly has support.

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Reply 9 of 10, by The Serpent Rider

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Ok, now I have full picture. Your Pentium 133 has locked multiplier, which was a thing, due to rebranding scams done with unlocked steppings, so it can be only underclocked. Additionally that's Intel OEM motheboard which can recognize that, but DELL has probably left some oversight in the firmware.

I must be some kind of standard: the anonymous gangbanger of the 21st century.

Reply 10 of 10, by Soap

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The Serpent Rider wrote on 2022-04-19, 17:20:

Ok, now I have full picture. Your Pentium 133 has locked multiplier, which was a thing, due to rebranding scams done with unlocked steppings, so it can be only underclocked. Additionally that's Intel OEM motheboard which can recognize that, but DELL has probably left some oversight in the firmware.

I see and makes complete sense now, this thing has been in parents loft complete with monitor\speakers\mouse\keyboard since about 97/98.

Has been fun over last couple of weeks getting it going again, my knowledge of this era is rusty at best, I would have been about 12 when parents bought this and my Dad strictly handled the upgrades, just found the Voodoo 1 for it too.