I have to call a lady tomorrow and give her some bad news. The power supply unit (a.k.a the “PSU” – the thing you plug the power cord in to on the back of your desktop PC) and possibly the motherboard in her PC that she bought a couple years back have failed (a power spike is the suspected culprit). I can’t diagnose whether her motherboard has failed because it’s a proprietary motherboard that connects to a proprietary PSU using a proprietary pin-out. In other words, I can’t just grab another PSU and connect it to the motherboard to see if the motherboard is still good. Why? Because this PC does not conform to any established “form factor.” One purpose of desktop PCs conforming to a form factor (examples include ATX, BTX, extended ATX, micro-ATX and mini-ITX) is to ensure the compatibility of parts between PCs of like form factors. So if I have a PC that conforms to the ATX form factor, and my PSU goes bad, I can walk in to my local PC parts store and ask for a PSU that conforms to the ATX form factor. Then I’ll know that the PSU I’m purchasing can physically be installed in my PC. I’ll need to know a few other things to be certain that I’m purchasing a good PSU for my PC and my needs… but I can rest assured that I can physically install that PSU. When my PC conforms to a certain established form factor, I can easily buy compatible third party parts off the shelf for my PC if I want to.
So I bet you can guess why some manufacturers like to use proprietary parts… if the lady whose PC I just diagnosed with a bad PSU wants to replace that PSU, only the manufacturer sells the part she needs brand new. And guess how much they want for it… $108 plus $18 shipping! And if she winds up needing her motherboard replaced, that’ll be an extra $229+$18. I will advise her not to bother fixing this PC. She could easily buy a new one for what she’d spend on the parts. Of course, one could buy these parts, used, on eBay, much cheaper. But I don’t do that because it’s a real crap shoot as to what you’re going to get. I don’t want to fix someone’s PC only to have it break down again a week later.
The lesson here is that, when you buy a new desktop PC (I’m not talking about all-in-ones… I honestly have no idea if there even are established form factors for all-in-ones), ask what form factor it conforms to. The salesperson may not be able to tell you right off the top of the their head what form factor a given PC conforms to but they should be able to look it up for you or ask someone who knows. Please note that “Small Form Factor” is not a form factor. “Small Form Factor” is a term manufacturers use (with no actual normalized meaning) to describe PCs that have been designed with space-saving in mind. So, some “Small Form Factor” PCs actually comply with an established form factor and some do not. So if a salesperson tells you that the form factor of the PC you’re considering is “Small Form Factor,” you can either try to explain to him or her what I’ve just explained to you, or you can find someone more knowledgeable.
It doesn’t really matter that much which form factor you choose so long as it’s an actual form factor. ATX is the standard for desktop PCs. If you’re looking to enjoy the widest possible selection of replacements when a component breaks down, you can’t beat ATX.
I do have a bit of good news for the lady when I call her tomorrow. Her data is just fine. Her hard drive is undamaged. So at least there’s that.