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Discussion Starter #1
I've heard that the Athlon XP processors pull power from the 5v rail, but some other things I've read said otherwise.

I'm turning an old computer into a CarPC, so I need to figure out which Car Power Supply to pick - And my decision will be greatly influenced by weather power is pulled from 5v or 12v, since most of the car psus wouldn't have enough amps on the 5v to power the CPU.
 

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No sir, I don't like it.
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The reason for the confusion online is because some motherboards pull from the +12V rail (generally the newer boards) and others still pull from the +5V rail.

In short, it depends on your motherboard.

Do you have a voltmeter/multimeter handy?
 

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if its on an Am2 board, your power should be running from the 12v rail
 

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Discussion Starter #4
The reason for the confusion online is because some motherboards pull from the +12V rail (generally the newer boards) and others still pull from the +5V rail.

In short, it depends on your motherboard.

Do you have a voltmeter/multimeter handy?
No, I don't. I'll see how much they cost, though.

It's a shame that motherboard manufactures don't seem to give too much information about that stuff. I'm pretty sure this one would be a 5v model though, because it was made in 2002, I believe.

MSI Computer Corp. - Product
 

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Discussion Starter #8
I emailed MSI technical support. Lets see how willing they are to provide support for such an old board..
 

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No sir, I don't like it.
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The pic on MSI's site is really crappy, but I can make out a single voltage stabilizer circuit.

It's very likely that this board powers the CPU on the +5V rail.

EDIT: looking even closer, am I seeing a 4-pin molex connector just north of the northbridge chipset? Is it for the power supply?
 

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Discussion Starter #14 (Edited)
That's a good question.... The only other device to pull from the 5v would be a 2.5" (Laptop) HDD, which I doubt pulls more than 3 amps.

edit: I looked at my laptop's broken hdd, and it says it pulls 1amp from 5v, so it should be fine.

USB Devices only pull from from +5Vsb right? Because there will be many USB devices connected.

I'd also have to consider how of the +5v the mobo may steal.
 

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No sir, I don't like it.
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USB Devices only pull from from +5Vsb right? Because there will be many USB devices connected.

I'd also have to consider how of the +5v the mobo may steal.
Correct, but the USB spec limits them to drawing 0.5A per connected device. From my experience, most USB devices use much less than the maximum.
 

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Discussion Starter #16
I love how the email address in their manual doesn't even exist anymore.
This is an automatically generated Delivery Status Notification

Delivery to the following recipient failed permanently:

[email protected]

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Google tried to deliver your message, but it was rejected by the recipient domain. We recommend contacting the other email provider for further information about the cause of this error. The error that the other server returned was: 550 550 <[email protected]>: Recipient address rejected: User unknown in local recipient table (state 14).
 

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This is mainboard dependant,

The Asus A7N series powers from the 12v line which is why they are so good at killing Antec's cheap **** power supplies. While others power from 3.3v
 

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No sir, I don't like it.
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3.3V? For an Athlon XP? oO

The last processor to use the 3.3V rail was the first-gen Pentium 3's (Katmai core).
 

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