VOGONS


First post, by Baoran

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Anyone knows what is the actual difference of low voltage version of K6-III+ cpu? Both the ones I have are marked to be 1.6V. Is there some kind of physical difference to 2.0V version or are they just binned cpus that are judged to not handle higher voltages and clockspeeds as well as some others?

I know you can overclock and run them at 2.0V since most motherboards dont support 1.6V, but I am just interested in what the actual physical difference is between for example 500Mhz 2.0V version and 400Mhz 1.6V version.

Reply 1 of 22, by brian105

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It's likely just binned to run at a lower voltage and clock speed.

Presario 5284: K6-2+ 550 ACZ @ 600 2v, 256MB PC133, GeForce4 MX 440SE 64MB, MVP3, Maxtor SATA/150 PCI card, 16GB Sandisk U100 SATA SSD
2007 Desktop: Athlon 64 X2 6000+, Asus M2v-MX SE, Foxconn 7950GT 512mb, 4GB DDR2 800, Audigy 2 ZS, WinME/XP

Reply 3 of 22, by RaiderOfLostVoodoo

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stef80 wrote on 2022-04-27, 07:35:

1.6V@400MHz or 2.0V@550/570MHz , you could probably reverse it and both would work.

This.
The 400MHz@1.6V one and the 550MHz@2.0V one are pretty much same binning quality. There's no point in paying 300 bucks for the 550MHz one, unless you're a hardcore collector. The low voltage 400MHz is just as good.

Reply 4 of 22, by shamino

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These numbers are from memory, but I think it's correct:
AMD's datasheet lists 3 low voltage versions of the K6-3+
400MHz 1.6V
450MHz 1.7V
500MHz 1.8V
The faster parts from that list were guaranteed to also run at the lower speed/voltage settings. This means the highest quality parts were supposed to be the 500Mhz 1.8V chips, but in practical reality the 400MHz 1.6V parts have proven to be very overclockable so it really doesn't matter which one you get.

I don't know what the norm is, but my 400Mhz 1.6V runs totally stable at 550MHz 1.8V. It hits a wall trying to reach 600MHz though. I got it to run 600Mhz at something like 2.05V but I didn't want to go any further and it still wasn't stable.

Reply 5 of 22, by brian105

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shamino wrote on 2022-04-27, 23:34:
These numbers are from memory, but I think it's correct: AMD's datasheet lists 3 low voltage versions of the K6-3+ 400MHz 1.6V 4 […]
Show full quote

These numbers are from memory, but I think it's correct:
AMD's datasheet lists 3 low voltage versions of the K6-3+
400MHz 1.6V
450MHz 1.7V
500MHz 1.8V
The faster parts from that list were guaranteed to also run at the lower speed/voltage settings. This means the highest quality parts were supposed to be the 500Mhz 1.8V chips, but in practical reality the 400MHz 1.6V parts have proven to be very overclockable so it really doesn't matter which one you get.

I don't know what the norm is, but my 400Mhz 1.6V runs totally stable at 550MHz 1.8V. It hits a wall trying to reach 600MHz though. I got it to run 600Mhz at something like 2.05V but I didn't want to go any further and it still wasn't stable.

That's pretty normal though, and 2.0v is a perfectly normal voltage for these chips since the regular 2+/3+ runs at that voltage. These chips are nothing special in the slightest; they were just tested to be stable at lower voltages.

Presario 5284: K6-2+ 550 ACZ @ 600 2v, 256MB PC133, GeForce4 MX 440SE 64MB, MVP3, Maxtor SATA/150 PCI card, 16GB Sandisk U100 SATA SSD
2007 Desktop: Athlon 64 X2 6000+, Asus M2v-MX SE, Foxconn 7950GT 512mb, 4GB DDR2 800, Audigy 2 ZS, WinME/XP

Reply 6 of 22, by Sphere478

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stef80 wrote on 2022-04-27, 07:35:

1.6V@400MHz or 2.0V@550/570MHz , you could probably reverse it and both would work.

I can confirm that my 550 and 570 chips will run at 1.6v 400-450mhz

Yeah, I’m pretty sure that they are simply using the same core but were just given a different rating to fit different applications. Of course based on binning results and market need.

This being different from the cyrix low voltage 2.2v variants, which actually in the case of the 300gp do seem to be using a later core than the 300gp 2.9v versions.

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 7 of 22, by Baoran

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shamino wrote on 2022-04-27, 23:34:
These numbers are from memory, but I think it's correct: AMD's datasheet lists 3 low voltage versions of the K6-3+ 400MHz 1.6V 4 […]
Show full quote

These numbers are from memory, but I think it's correct:
AMD's datasheet lists 3 low voltage versions of the K6-3+
400MHz 1.6V
450MHz 1.7V
500MHz 1.8V
The faster parts from that list were guaranteed to also run at the lower speed/voltage settings. This means the highest quality parts were supposed to be the 500Mhz 1.8V chips, but in practical reality the 400MHz 1.6V parts have proven to be very overclockable so it really doesn't matter which one you get.

I don't know what the norm is, but my 400Mhz 1.6V runs totally stable at 550MHz 1.8V. It hits a wall trying to reach 600MHz though. I got it to run 600Mhz at something like 2.05V but I didn't want to go any further and it still wasn't stable.

What socket 7 motherboards can reach to 1.8V and 1.6V voltages? Only motherboards I have that can run these cpus dont go lower than 2V. My 1.6V 400Mhz part also seems runs fine at 550Mhz at 2V, but after if I do "setmul 6" all dos programs I try to run crash with errors like "division by zero" and overflow errors so it clearly cant handle it.

Reply 8 of 22, by RaiderOfLostVoodoo

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Baoran wrote on 2022-04-28, 02:43:

What socket 7 motherboards can reach to 1.8V and 1.6V voltages? Only motherboards I have that can run these cpus dont go lower than 2V. My 1.6V 400Mhz part also seems runs fine at 550Mhz at 2V, but after if I do "setmul 6" all dos programs I try to run crash with errors like "division by zero" and overflow errors so it clearly cant handle it.

DFI K6XV3+/66 for example.
Can even go down to 1.3V. 😜

Reply 9 of 22, by Sphere478

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Baoran wrote on 2022-04-28, 02:43:
shamino wrote on 2022-04-27, 23:34:
These numbers are from memory, but I think it's correct: AMD's datasheet lists 3 low voltage versions of the K6-3+ 400MHz 1.6V 4 […]
Show full quote

These numbers are from memory, but I think it's correct:
AMD's datasheet lists 3 low voltage versions of the K6-3+
400MHz 1.6V
450MHz 1.7V
500MHz 1.8V
The faster parts from that list were guaranteed to also run at the lower speed/voltage settings. This means the highest quality parts were supposed to be the 500Mhz 1.8V chips, but in practical reality the 400MHz 1.6V parts have proven to be very overclockable so it really doesn't matter which one you get.

I don't know what the norm is, but my 400Mhz 1.6V runs totally stable at 550MHz 1.8V. It hits a wall trying to reach 600MHz though. I got it to run 600Mhz at something like 2.05V but I didn't want to go any further and it still wasn't stable.

What socket 7 motherboards can reach to 1.8V and 1.6V voltages? Only motherboards I have that can run these cpus dont go lower than 2V. My 1.6V 400Mhz part also seems runs fine at 550Mhz at 2V, but after if I do "setmul 6" all dos programs I try to run crash with errors like "division by zero" and overflow errors so it clearly cant handle it.

Iwill p55xb2 can do 1.6v
Freeway design ultra can do 1.3-3.5v?
Kingston interposer can do 1.3-3.5?
I think the asus p5a 1.05 and 1.06 can do 1.3-3.5?

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 10 of 22, by janih

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Sphere478 wrote on 2022-04-28, 04:18:

I think the asus p5a 1.05 and 1.06 can do 1.3-3.5?

So on Asus P5A only the newer revision can do voltages lower than 2.0? Too bad because my P5A is 1.03 or 1.04 and I was thinking on putting a low voltage K6-III+ there, but I guess I have to run it at higher voltage then.

Reply 11 of 22, by Sphere478

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janih wrote on 2022-04-28, 09:25:
Sphere478 wrote on 2022-04-28, 04:18:

I think the asus p5a 1.05 and 1.06 can do 1.3-3.5?

So on Asus P5A only the newer revision can do voltages lower than 2.0? Too bad because my P5A is 1.03 or 1.04 and I was thinking on putting a low voltage K6-III+ there, but I guess I have to run it at higher voltage then.

I wouldn’t give a second thought to running a 1.6v k6-3+ at 2.0-2.2v

99.9% sure they are the same core.

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 12 of 22, by Baoran

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Sphere478 wrote on 2022-04-28, 09:58:
janih wrote on 2022-04-28, 09:25:
Sphere478 wrote on 2022-04-28, 04:18:

I think the asus p5a 1.05 and 1.06 can do 1.3-3.5?

So on Asus P5A only the newer revision can do voltages lower than 2.0? Too bad because my P5A is 1.03 or 1.04 and I was thinking on putting a low voltage K6-III+ there, but I guess I have to run it at higher voltage then.

I wouldn’t give a second thought to running a 1.6v k6-3+ at 2.0-2.2v

99.9% sure they are the same core.

Same core for sure, but probably binned differently. Like one has better silicon than the other because of manufacturing defects and such.

Reply 14 of 22, by shamino

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Baoran wrote on 2022-04-28, 02:43:

What socket 7 motherboards can reach to 1.8V and 1.6V voltages? Only motherboards I have that can run these cpus dont go lower than 2V. My 1.6V 400Mhz part also seems runs fine at 550Mhz at 2V, but after if I do "setmul 6" all dos programs I try to run crash with errors like "division by zero" and overflow errors so it clearly cant handle it.

Socket 7 desktop boards don't normally document settings that low, but many late production boards can do them. You have to look at what voltage regulator chip you have and figure out the jumpers to activate those lower settings.
If you can find places to check Vcore with a multimeter then you can verify the voltage without a chip installed.

My board is a Tyan S1590 which has a regulator chip that meets the spec for Coppermine P3s, so it can go down to 1.3V once the jumpers are figured out.
That's a matter of luck combined with when the board was made. I'm sure many examples of that board don't have the same regulator chip, and older revisions had fewer VID jumpers so the lower ranges weren't accessible even if the chip could do them.

Reply 15 of 22, by Baoran

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shamino wrote on 2022-04-28, 10:20:
Socket 7 desktop boards don't normally document settings that low, but many late production boards can do them. You have to loo […]
Show full quote
Baoran wrote on 2022-04-28, 02:43:

What socket 7 motherboards can reach to 1.8V and 1.6V voltages? Only motherboards I have that can run these cpus dont go lower than 2V. My 1.6V 400Mhz part also seems runs fine at 550Mhz at 2V, but after if I do "setmul 6" all dos programs I try to run crash with errors like "division by zero" and overflow errors so it clearly cant handle it.

Socket 7 desktop boards don't normally document settings that low, but many late production boards can do them. You have to look at what voltage regulator chip you have and figure out the jumpers to activate those lower settings.
If you can find places to check Vcore with a multimeter then you can verify the voltage without a chip installed.

My board is a Tyan S1590 which has a regulator chip that meets the spec for Coppermine P3s, so it can go down to 1.3V once the jumpers are figured out.
That's a matter of luck combined with when the board was made. I'm sure many examples of that board don't have the same regulator chip, and older revisions had fewer VID jumpers so the lower ranges weren't accessible even if the chip could do them.

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.

Reply 16 of 22, by Sphere478

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Baoran wrote on 2022-04-28, 11:10:
shamino wrote on 2022-04-28, 10:20:
Socket 7 desktop boards don't normally document settings that low, but many late production boards can do them. You have to loo […]
Show full quote
Baoran wrote on 2022-04-28, 02:43:

What socket 7 motherboards can reach to 1.8V and 1.6V voltages? Only motherboards I have that can run these cpus dont go lower than 2V. My 1.6V 400Mhz part also seems runs fine at 550Mhz at 2V, but after if I do "setmul 6" all dos programs I try to run crash with errors like "division by zero" and overflow errors so it clearly cant handle it.

Socket 7 desktop boards don't normally document settings that low, but many late production boards can do them. You have to look at what voltage regulator chip you have and figure out the jumpers to activate those lower settings.
If you can find places to check Vcore with a multimeter then you can verify the voltage without a chip installed.

My board is a Tyan S1590 which has a regulator chip that meets the spec for Coppermine P3s, so it can go down to 1.3V once the jumpers are figured out.
That's a matter of luck combined with when the board was made. I'm sure many examples of that board don't have the same regulator chip, and older revisions had fewer VID jumpers so the lower ranges weren't accessible even if the chip could do them.

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.

That’s a common setup, 2.0 or 2.1 to 3.5

Many mobos have that range.

2.0-2.2 works fine for all the lv socket 7 chips. Be it 1.6v 3+, a 2.2v mII, a rise, or even a tillamook. The lv mii kinda likes to have at least 2.2 though

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 18 of 22, by Sphere478

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Carrera wrote on 2022-04-28, 14:31:

Back in the day I used an Epox motherboard to run a K6 III+ I thnk... even had an app to change the clock on the fly..

central tweaking unit is a good one for win 9x,/ME (best of all of the many programs probably, there are like 10), forget the name of the good one for xp

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 19 of 22, by shamino

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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.