VOGONS


Reply 20 of 22, by Baoran

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shamino wrote on 2022-04-28, 22:49:
Baoran wrote on 2022-04-28, 11:10:

From looking documented jumpers on my motherboard it just feels like base voltage is 2.0V with all jumpers open and closing jumpers just add 0.1V, 0.2V, 0.4V and 0.8V to that so closing all of them would make it 3.5V total.

On an Intel spec compliant voltage regulator I believe 2.0V is the minimum if the high order VID signal to the regulator has been hardwired and not connected to a jumper. If it's fully jumpered then there would be 5 VID jumpers. If you were to dig into it it's possible you could find a way to add the extra bit, but it shouldn't be a big deal to run 2.0V.

This is how it is pretty much. JP30 are the ones I mentioned before and I think JP1 and JP2 are probably related to if I/O voltage and cpu voltage are the same or different.

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Reply 21 of 22, by Sphere478

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Baoran wrote on 2022-04-29, 04:19:
shamino wrote on 2022-04-28, 22:49:
Baoran wrote on 2022-04-28, 11:10:

From looking documented jumpers on my motherboard it just feels like base voltage is 2.0V with all jumpers open and closing jumpers just add 0.1V, 0.2V, 0.4V and 0.8V to that so closing all of them would make it 3.5V total.

On an Intel spec compliant voltage regulator I believe 2.0V is the minimum if the high order VID signal to the regulator has been hardwired and not connected to a jumper. If it's fully jumpered then there would be 5 VID jumpers. If you were to dig into it it's possible you could find a way to add the extra bit, but it shouldn't be a big deal to run 2.0V.

This is how it is pretty much. JP30 are the ones I mentioned before and I think JP1 and JP2 are probably related to if I/O voltage and cpu voltage are the same or different.

table1.jpg

I see some errors on that table that I'll point out for future google searchers. it must have come out before socket 7 end of life. (which is kinda obvious now looking at the lack of k6-2)

for example:
-There are several p55c pentium mmx chips that are lower than 2.8v Vcore Vcc2,
-There is the tillamook (2.5I/O Vcc3, 1.9 Vcore Vcc2) which is called a pentium MMX also
-They make no mention of LV cyrix chips (2.2v Vcore Vcc2)
-K6(1,2,3,2+,3+) came in flavors all the way down to 1.6v

Sphere's PCB projects.
-
Sphere’s socket 5/7 cpu collection.
-
SUCCESSFUL K6-2+ to K6-3+ Full Cache Enable Mod
-
Tyan S1564S to S1564D single to dual processor conversion (also s1563 and s1562)

Reply 22 of 22, by Baoran

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Sphere478 wrote on 2022-04-29, 06:59:
I see some errors on that table that I'll point out for future google searchers. it must have come out before socket 7 end of li […]
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Baoran wrote on 2022-04-29, 04:19:
shamino wrote on 2022-04-28, 22:49:

On an Intel spec compliant voltage regulator I believe 2.0V is the minimum if the high order VID signal to the regulator has been hardwired and not connected to a jumper. If it's fully jumpered then there would be 5 VID jumpers. If you were to dig into it it's possible you could find a way to add the extra bit, but it shouldn't be a big deal to run 2.0V.

This is how it is pretty much. JP30 are the ones I mentioned before and I think JP1 and JP2 are probably related to if I/O voltage and cpu voltage are the same or different.

table1.jpg

I see some errors on that table that I'll point out for future google searchers. it must have come out before socket 7 end of life. (which is kinda obvious now looking at the lack of k6-2)

for example:
-There are several p55c pentium mmx chips that are lower than 2.8v Vcore Vcc2,
-There is the tillamook (2.5I/O Vcc3, 1.9 Vcore Vcc2) which is called a pentium MMX also
-They make no mention of LV cyrix chips (2.2v Vcore Vcc2)
-K6(1,2,3,2+,3+) came in flavors all the way down to 1.6v

My motherboard is earlier revision of the motherboard and manual is dated September 1998. In newer revisions of the motherboard they changed all voltages to be set using 5 switches instead of those jumpers which can be seen online on manual that is dated June 1999.