TYAN S2466 (Tiger MPX) - Dual Socket A (PGA 462)

red-ray wrote on 2020-11-17, 23:37:

TYAN S2466 (Tiger MPX) - Dual Socket A (PGA 462)

Nice. Yeah, that has a 4-pin supplemental CPU power connector alright.

The 4-pin supplemental power connector delivers 12V exclusively (the four pins are +12V, +12V, ground, ground). My understanding is that motherboards that use this connector are using it to service the CPU via VRMs that step down the 12V to whatever the CPU requires.

As you mentioned, there was a shift in the industry toward using the 12V rail (12V-centric, as you put it) which roughly coincided with the Pentium 4. The 4-pin supplemental power connector (called ATX12V) was introduced specifically to enable this shift.

The 20-pin ATX power connector only has ONE pin that supplies 12V (the newer 24-pin connector added a second 12V pin). So a typical motherboard of the era might have:
20-pin ATX only: ONE 12V pin for the entire motherboard
or
20-pin ATX + 4-pin ATX12V: THREE 12V pins for the entire motherboard

This suggests that any motherboards that lack the supplemental 4-pin power connector will almost certainly not be '12V-centric'. They would have only ONE 12V connection to the power supply, which would likely be insufficient to feed the CPU with primarily 12V.

For some good further reading I recommend checking out:
http://www.playtool.com/pages/psuconnectors/c … .html#atxmain20
http://www.playtool.com/pages/psurailhistory/rails.html

bZbZbZ wrote on 2020-11-18, 01:50:

The 4-pin supplemental power connector delivers 12V exclusively (the four pins are +12V, +12V, ground, ground). My understandin […]
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The 4-pin supplemental power connector delivers 12V exclusively (the four pins are +12V, +12V, ground, ground). My understanding is that motherboards that use this connector are using it to service the CPU via VRMs that step down the 12V to whatever the CPU requires.

As you mentioned, there was a shift in the industry toward using the 12V rail (12V-centric, as you put it) which roughly coincided with the Pentium 4. The 4-pin supplemental power connector (called ATX12V) was introduced specifically to enable this shift.

The 20-pin ATX power connector only has ONE pin that supplies 12V (the newer 24-pin connector added a second 12V pin). So a typical motherboard of the era might have:
20-pin ATX only: ONE 12V pin for the entire motherboard
or
20-pin ATX + 4-pin ATX12V: THREE 12V pins for the entire motherboard

This suggests that any motherboards that lack the supplemental 4-pin power connector will almost certainly not be '12V-centric'. They would have only ONE 12V connection to the power supply, which would likely be insufficient to feed the CPU with primarily 12V.

For some good further reading I recommend checking out:
http://www.playtool.com/pages/psuconnectors/c … .html#atxmain20
http://www.playtool.com/pages/psurailhistory/rails.html

Actually quite informative. Thanks.

Also, I'll start maintaining a list of motherboards in my OP so that people can quickly research what motherboards have the ATX12V cable.

I think most nforce 2 boards had the 12v connector. I've never experienced a reliable nforce 2 board though so I don't use them in anything.

I can just say that my Asus A7N8X Deluxe v2.0 (nforce2 ultra 400) does not have the atx12v connector, so that one is quite likely 5v-centric. I use an old Enermax PSU with strong 5V rail

FIC K7MNF-64 is an nForce2 mATX motherboard that uses the 4-pin +12V connector, I believe it was used on certain models of eMachines PCs. It is really bare bones but very reliable in my experience.

Some nforce 2 boards that definitely do use the 4-pin 12V CPU connector:
- Abit's NF7 in all its variants and revisions
- MSI's K7N2 and its variants
- Gigabyte's GA-7N400, GA-7NNXP
- DFI's Lanparty NFII Ultra

VIA and SIS motherboards are hit or miss, when it comes to separate 12v connector.

I can list a few boards that I know have 12V rails (and I also own):

• Shuttle AK39N - KT400, uses molex connector for 12V distribution:
  https://www.shuttle.eu/_archive/older/en/ak39n.htm
• ECS N2U400 - nForce2, P4 connector:
  https://www.ecs.com.tw/ECSWebSite/Product/Pro … 0462-LL-AMD-RR-
• Albatron KM400A - KM400, P4 connector:
  http://www.motherboard.cz/mb/albatron/KM400APro.htm

You don't need to list Nforce 2 boards with 12v connector. Much easier to list exceptions which don't have it.

The Serpent Rider wrote on 2020-11-18, 13:18:

You don't need to list Nforce 2 boards with 12v connector. Much easier to list exceptions which don't have it.

I think that'll be like over half of all Socket A boards, 🤣.

The Serpent Rider wrote on 2020-11-18, 13:18:

You don't need to list Nforce 2 boards with 12v connector. Much easier to list exceptions which don't have it.

the_ultra_code wrote on 2020-11-18, 15:07:

I think that'll be like over half of all Socket A boards, 🤣.

I'd still suggest to include all the full model numbers and differentiate between the 2 as leaving names out will make it harder to find using a search engine.

Tetrium wrote on 2020-11-18, 15:17:

I'd still suggest to include all the full model numbers and differentiate between the 2 as leaving names out will make it harder to find using a search engine.

So list both boards with and without the 12V connector?

I think that'll be like over half of all Socket A boards

On other chipsets, but majority of Nforce 2 boards had 12v connector. It's just counter productive to list all of them. When it comes to VIA and SIS chipsets, the situations is flipped - minority of boards, even most late ones, had 12v connector.

The 12V CPU power connector was not quite as ubiquitous on nForce2 boards as some are suggesting. There were quite a lot of boards still without it, such as:
- AOpen AK79G Max
- Biostar M7NCD, M7NCG (mATX)
- Chaintech 7NJL6, 7NJS, 7NIL1 (mATX), 7NIF2 (mATX)
- Epox 8RDA+

Though at least in Epox's case, they did add it to later similar boards, such as 8RDA3+, 8RGA+ or 8RGM3I (mATX).

Some more non-nforce2 boards that did have the 12V CPU power connector:
- Abit AT7 MAX2 (VIA KT400) (but not the regular AT7, which was KT333 based)
- Abit KD7/KD7-S/KD7-G (VIA KT400)
- Abit KV7/KV7-V (VIA KT600)
- MSI KT6 Delta (VIA KT600)
- Epox 8VTAI (KT880)

the_ultra_code wrote on 2020-11-18, 15:31:

Tetrium wrote on 2020-11-18, 15:17:

I'd still suggest to include all the full model numbers and differentiate between the 2 as leaving names out will make it harder to find using a search engine.

So list both boards with and without the 12V connector?

Yes. This way you'll also have an easy way to check which boards you've verified previously regardless of whether or not these have the P4 connector.
See this page for an example https://www.vogonswiki.com/index.php/List_of_ … 70_motherboards in which specific features of all the boards in the table are listed like AGP and the presence of ISA slots.

When it comes to dual CPU Socket A motherboards, you can list the Asus A7M266-D as well.
It has not only the 12V connector, but also the ATX-Aux power connector (6 pins: 3x Ground, 2x +3.3V, 1x +5V).

(I happen to own this board, but unfortunately it doesn't POST, probably needs to be recapped, some or the larger caps are blown and have leaked.)

Edit: Its single-CPU sibling, the A7M266, seems to lack both additional power connectors and is therefore probably "5V-centric".

Tetrium wrote on 2020-11-18, 17:58:

Yes. This way you'll also have an easy way to check which boards you've verified previously regardless of whether or not these have the P4 connector.
See this page for an example https://www.vogonswiki.com/index.php/List_of_ … 70_motherboards in which specific features of all the boards in the table are listed like AGP and the presence of ISA slots.

😓 Work for another day. For now, I'll just list those that have a 12V connector, and maybe later, if free-time permits, I'll make a VOGONS wiki post like that.

gex85 wrote on 2020-11-18, 18:15:

When it comes to dual CPU Socket A motherboards, you can list the Asus A7M266-D as well.
It has not only the 12V connector, but also the ATX-Aux power connector (6 pins: 3x Ground, 2x +3.3V, 1x +5V).

(I happen to own this board, but unfortunately it doesn't POST, probably needs to be recapped, some or the larger caps are blown and have leaked.)

I can recap that for you, if you wish. 😀