ATX vs. mATX: Power Consumption (2024)

Is it true that a comparable mATX board would consume less power than an ATX?
The way I see it is that if the only difference is in the number of expansion slots (all other outputs: USB, audio, etc. being the same) then power consumption would be the same, right? I mean if there isn't a card in the slot then it shouldn't matter for power consumption. Unless the board needs to keep power on reserve????

If there is a difference, how many watts are we talking here?

All things being equal an mATX board will take the same amount of power, but all things are not equal, even if the listed features are identical, there are other, unlisted (or unnnoticed features).
For example, remember anandtech's article about the exploding capacitors on 780G boards? those boards are typically mATX... even the gigabyte board with the 5 phase power that doesnt explode at 125 watt, does explode if Oced... compare that to some ATX boards with 8 phases.. And both gigabyte and asus are now all about "saving power" by disabling unneeded power phases... my gigabyte board with my E8400 works at 2/6 on idle, and 4/6 at 100% CPU usage... so those last 2 power phases are just wasting electricity unless I OC.

The question is... COULD they fit more power phases on a smaller board... I think they are actually very small, so yes...

Originally posted by: Nucleus111
Is it true that a comparable mATX board would consume less power than an ATX?
The way I see it is that if the only difference is in the number of expansion slots (all other outputs: USB, audio, etc. being the same) then power consumption would be the same, right? I mean if there isn't a card in the slot then it shouldn't matter for power consumption. Unless the board needs to keep power on reserve????

If there is a difference, how many watts are we talking here?

Click to expand...

The low-power consumption record (according to Tom) in an mATX is 41.72 watts at idle with C&Q enabled (drew 74.37 watts when playing back a Blu-ray movie with PowerDVD 7.3.).

This was with an Gigabyte AMD 780g, Athlon X2 4850E with stock cooler, 2 GB A-DATA DDR2 -800, Blu-ray ROM and a WD 320gb hard drive.

So NO. Power consumption is not the same Lookee here

What exactly are you trying to compare there? The OP was asking whether two comparable motherboards, one ATX and the other mATX, would differ in power consumption. You're comparing two boards with completely different platforms, chipsets, and other configuration, it seems.

A comparison to a regular ATX 780G with the exact same CPU, RAM, and other parts would be a lot more relevant.

Originally posted by: heyheyboobooThe low-power consumption record (according to Tom) in an mATX is 41.72 watts at idle with C&Q enabled (drew 74.37 watts when playing back a Blu-ray movie with PowerDVD 7.3.).

Click to expand...

Not bad but not the best.
frank2003 at SPCR: "my 780G mATX can do Blu-Ray @ 45-48W"
http://www.silentpcreview.com/.../viewtopic.php?t=48603

Originally posted by: taltamir
All things being equal an mATX board will take the same amount of power, but all things are not equal, even if the listed features are identical, there are other, unlisted (or unnnoticed features).
For example, remember anandtech's article about the exploding capacitors on 780G boards? those boards are typically mATX... even the gigabyte board with the 5 phase power that doesnt explode at 125 watt, does explode if Oced... compare that to some ATX boards with 8 phases.. And both gigabyte and asus are now all about "saving power" by disabling unneeded power phases... my gigabyte board with my E8400 works at 2/6 on idle, and 4/6 at 100% CPU usage... so those last 2 power phases are just wasting electricity unless I OC.

The question is... COULD they fit more power phases on a smaller board... I think they are actually very small, so yes...

Click to expand...

So, besides the obvious design features of the chipset, the determining factor would be power phases? The more, with the ability to turn them off, the better?