Micro ATX vs ATX

[aidan22cheese]

Whats are some disadvantages of getting a micro atx motherboard compared to getting an ATX motherboard. Im debating on which one i should get since micro atx motherboards are cheaper.

[minibois]

Just now, aidan22cheese said:

Whats are some disadvantages of getting a micro atx motherboard compared to getting an ATX motherboard. Im debating on which one i should get since micro atx motherboards are cheaper.

The difference comes down to a board vs. board level. Not all ATX or mATX boards are the same.

Generally though, mATX boards have fewer PCIE slots, could have fewer M.2 slots (but that doesn't have to be the case) and mATX boards are just smaller.

If you're getting an ATX case, an mATX motherboard could look silly, but unless you really need those last PCIE slots, I think mATX is the motherboard size that makes the most sense for most people.

[aidan22cheese]

1 minute ago, minibois said:

The difference comes down to a board vs. board level. Not all ATX or mATX boards are the same.

Generally though, mATX boards have fewer PCIE slots, could have fewer M.2 slots (but that doesn't have to be the case) and mATX boards are just smaller.

If you're getting an ATX case, an mATX motherboard could look silly, but unless you really need those last PCIE slots, I think mATX is the motherboard size that makes the most sense for most people.

oh that makes sense. Isnt there better airflow and more compatability in an atx case though?

[DailyProcrastinator]

2 minutes ago, aidan22cheese said:

Whats are some disadvantages of getting a micro atx motherboard compared to getting an ATX motherboard. Im debating on which one i should get since micro atx motherboards are cheaper.

Typically cheaper = lower quality VRMs, and less features and expansion slots, this has little to do with overall form factor though. You can get micro ATX boards with good VRMs as well.

 

[minibois]

Just now, aidan22cheese said:

oh that makes sense. Isnt there better airflow and more compatability in an atx case though?

Better airflow depends on the case.

There are ATX cases with good and bad airflow and so is the case with mATX cases. ATX motherboards are only 6cm taller than mATX cases, which means it's half the height of another 120mm fan, so it's not like just by having an ATX case you will always be able to add a fan extra.

 

Compatibility is debatable too.

Space for two 3.5" drives and two 2.5" drives is basically standard, in mATX and ATX.

Room for a large videocard doesn't differ between mATX and ATX either. Same for room for a large PSU.

Not sure what 'Compatibility' you could otherwise be referring to.

[infigo]

Most differences comes down to case airflow and case expansion. 

For motherboards there are often fewer electrical limits on matx versions. Why? Well other than the first 16x slot and the first m.2 (on amd since 1000 series and on Intel with 11000 series).

All other pcie ports and m.2 share lanes, most often a 4x pcie 3.0 pipe from the CPU with only x570 double that with 4x 4.0 pipe that can then be split into lanes

 

But for the most parts they only gives 8 lanes of gen 2.0 (b450) or 3.0 (b550) of maximum bandwidth. So choosing say a Asus b550 ATX board most of the ports are disabled anyway since they only allow for one or two ways of expansion at a time due to the limited lanes. Matx have less ports and so less need to limit what is possible on the rest of the ones. 

On the Asus b550 tuf gaming wifi the only limit with lanes is that the bottom 4x is only used at 2x if any of the 1x ports are used, so no 4k60 capture card

But on the b550 tuf it have more 1x ports but same thing there the 4x port limits to 1x lane If any other 1x is populated. 

The ATX does it a bit differently the 4x and 1x share lanes so as Long as not all 1x and 4x ports is loaded at a time it will be fine. Intel also mostly does it that way too. 

But different manufactures priorities differently, MSI disable the second m.2 on b550 if a card is placed in the 4x port to always have the 1x ports available, and Asus you choose 1x or 4x expansion but with second m.2 always being active. 

But in he end all hat data must go through a 4x 3.0 pipe to the CPU so even though chipset might provide 8 lanes of 3.0 maximum, it is not possible to load more than the 4x bandwidth. 

And that is why x570, threadripper and x299 exist, more bandwidth from cpu to chipset or in the latter two, more lanes directly from CPUs