Difference between MicroATX and ATX?

[wannaoc]

Is it only the number of PCI slots and size?

 

[q149]

Size.

 

[Cjwinnit]

The sizes are the main factor here (apologies for the pun ). It doesn't really have much to do with the number of PCI slots, it's just easier to put more PCI slots on a bigger mobo.

 

[rdy2rave]

If you're building a pc go with ATX rather than microATX. You will thank me later.

 

[james.miller]

The sizes are the main factor here (apologies for the pun ). It doesn't really have much to do with the number of PCI slots, it's just easier to put more PCI slots on a bigger mobo.

if you think about it, it has everything to do with it. m-atx has a defined size, which limits the number of slots you can use since going beyond that would mean you no longer have an m-atx board (becuase it is too big)

If you're building a pc go with ATX rather than microATX. You will thank me later.

why? there are now fully-featured nvorce2 M-atx boards. what pci cards do you nedd when you have the lot on-board?

 

[rdy2rave]

If something breaks on the board or you are not satisfied with the features the motherboard has then size does matter. Many Micro-ATX cases only use half-height/half-length pci cards. Not only are the cards harder to find, they are often less feature-rich and as expensive as full cards.

I used to have a micro-atx pc and upgrading was not a fun time. Also, micro-atx cases get hotter than full cases because there is less air to circulate. Also, there is less room to work in.

For performance and upgrade reasons I recommend sticking to full-size ATX.

Cheers,
r2r

 

[james.miller]

* if something breaks then you either RAM or get a new one.
* if you buy an nforce 2 with sata, usb2,lan, firewire AND soundstorm, then you really dont need anything more.

as for performance, well an m-atx nforce 2 and full atx nforce2 perform identically - there is no difference.

quite honestly, if you wasn't happy and need say, scsi or a tape drive, then you wouldnt be using an m-atx case in the first place.

take a look at this for example.
http://www.ocworkbench.com/2003/shuttle/mn31n/mn31n-1.htm

the Shuttle MN31N mATX nForce2

has everything on-board.
MCP-T - firewire, lan and soundstorm
IGP - intergrated gf4 mx level graphics.
Spdif out
supports DUAL CHANNEL DDR400

and of course everything else associated with nforce2.

honestly, is theat not enough performance or features for you?

Features-wise, this board has some pretty nice features including 6 Channel audio, USB 2.0, AGP 8x, Dual Channel DDR333 support, integrated GF4 MX video, Dual Monitor Support but no TV out. There is also a BIOS that provides basic oc features like FSB and RAM timings adjustments. There are no voltage and multiplier controls in the BIOS

Quite honestly, i'd gladly drop the voltage options for a m-atx rig of that spec.

 

[Cjwinnit]

if you think about it, it has everything to do with it. m-atx has a defined size, which limits the number of slots you can use since going beyond that would mean you no longer have an m-atx board (becuase it is too big)

True, but the formfactors are defined by the sizes of the motherboards, not from how many PCI slots are on it. They could have been sneaky and put a few CNR, AMR slots there.

 

[rdy2rave]

What about the PSU in a micro-atx case? It's not like they can fit full-size units in there. Meaning you have a less stable ps that might have problems powering all your expensive micro-atx gear.

Ultimately all I'm saying is I'd rather work with a full-atx pc if I had a choice.

 

[james.miller]

True, but the formfactors are defined by the sizes of the motherboards, not from how many PCI slots are on it. They could have been sneaky and put a few CNR, AMR slots there.

yes, but the slots have to be in a set position. remember that m-atx boards follow the same basic design as the full atx boards. they use the same screw holes and the same positioning for the isa, pic and agp slots. They HAVE to otherwise the m-atx fit in the cases since all cases (excluding those "special" cases) also follow the same basic design.
If they started fitting slots wherever they liked, then those slots would be useless since they wouldnt like up with the slots in the cases.

 

[larva]

What about the PSU in a micro-atx case? It's not like they can fit full-size units in there. Meaning you have a less stable ps that might have problems powering all your expensive micro-atx gear.

Bingo! We have a winner. That is the problem with micro ATX, the power supply. They simply aren't large enough to deal with the combined output and thermal stresses placed upon them. If you have a micro case that takes a full size power supply (and they do exist, I have one in the basement), micro is great. But 99% of all micro cases accept only micro supplies, and this eliminates any of the truly capable power supplies on the market from consideration.

 

[james.miller]

come on larva, we're overclockers and modders - those psu's will fit if we want them to

 

[Mr B]

Bingo! We have a winner. That is the problem with micro ATX, the power supply. They simply aren't large enough to deal with the combined output and thermal stresses placed upon them. If you have a micro case that takes a full size power supply (and they do exist, I have one in the basement), micro is great. But 99% of all micro cases accept only micro supplies, and this eliminates any of the truly capable power supplies on the market from consideration.

I got lucky one day and found, in a dumpster, a mATX case that does quite easily fit a full size ATX PSU.

It also will just fit a D-Tek radiator under the drive "cage".

I enlarged the rear PSU opening to accomodate the full size PSU, and added a 92mm blowhole next to the I/O ports on the back as well.

It's running a CompUSA 300W PSU, powering a K7SEM with a 1800+ Pally (on air) with quite reasonable temps, with the original 80mm intake and that 92mm exhaust. Sitting on the shelf I have a Maze 2-1, and an Eheim 1046. One of these days I'll get the rest of the stuff I need for the H20, and a nF2 mATX board...ought to make for one heck of a LAN rig...

But yes...the PSU is the limiting factor in 99% of mATX cases, I agree. Ya just gotta find that 1 in a 100 case, and start cuttin'....

 

[Posidon42]

I am looking into these micro atx motherboards for building a server farm but I want to overclock them as well. The Shuttle board looks appealing and the price is right, but can it be overclocked? Has anyone ever tried this?

 

[ElectroSoldier]

The M-ATX standard is just that a standard, it dictates the physical size of the board just like AT and E-ATX, the amount of PCI slots is kind of a by product of the size, in that you cant put 6slots on a board that is by its design only capable of taking 4 (or less bepending on the lay out of the board your looking at).

The maimum number of standard PCI slots an AT board can have is 6 + 1 (the +1 is usually AGP) but that doesnt mean the a system can have only 6PCI slots, only that the AT standard distates the physical size and the size dictates the amount of slots that will fit (Ive got a server with 12PCI and 6ISA but I dont use half of them)

The more expansion slots (be it ISA or PCI) the greater the upgrade possabilities, a lot of the new board come with onboard LAN, FireWire, USB2, Sound, Graphics (like it or not) so all the slots provided are for upgrades even if you never use them you can if you wish.

Every board has a market and in that market it has +points and -points take it into a different market and its mostly -points.

But M-ATX is M-AT because of its size NOT the amount of PCI slots it has

Larva is right again with the PSU point, the most (not all) of the M-ATX cases run sub standard PSUs (compaired to OCin class PSUs or just normal PCs) and as such are really not sutable for OCin but that is not the market an M-ATX board is designed for or it would be sutied to OCin.
The M-ATX PSUs are hard to find and expensive, but most of all under powered (mostly in my experiance 250W)