Help: Total newbie, specific requirements

[R77]

Core questions are in pink, if you can only comment on some instead of all.

So the HDDs of my Mac Mini '11 are falling apart and I've been considering building my own because the perfect Mac for me doesn't exist. This will be my first time building a non-standard machine so half of the hardware codes look like gibberish to me, I'm going to need some advice. I have a friend who can help with the actual setup when it's time, but at first I would definitely have to decide what I'm even looking for. I'm looking at the wonderful buyer's guide list on this website but I'm afraid that I don't always know what I should be choosing for each purpose.

Summary of requirements:

• The computer would need to deal with graphics and audio work on a professionally pleasing level. (Currently, 1 displayport. MIDI via USB)
• The computer should be as quiet as possible. No whistling, whirring or especially resonance rattling.
• I dislike El Capitan and don't want to go there.
• The computer should have 3D/video capabilities "similar to a cheap/average PC", which is better than a Mac but a casual hobbyist grade is well sufficient.

Quietude
I know one other silence freak, and he said that it wasn't so much the case of his computer that made it silent, but it was the Noctua brand fans. Since he has an insane amount of HDDs but does completely different things than me, the amount of fans in his system can't really act as a reference for what I should get for mine. As Noctua fans weren't mentioned in the buyer's guide list, does anyone know if they could be an option?
How many fans I need is of course related to how heavy stress the computer is undergoing, but I'd like to estimate what would be the bare minimum to start out with, to avoid something spiking to the excessive temperatures that can cause real damage. I live in a country with proper 4 seasons, meaning that the summer months are the only time when the computer gets some extra heat stress. I never do multiple heavy tasks at once, only one heavy program is open at a time. The heaviest processes are related to either still graphics work (pro), heavily automated audio production (pro), and 3D modeling or gaming (few odd times per year, beginner/hobby-like). I think I should get an SSD as a boot drive, and 1-2 regular drives for data. With this in mind, how many fans do I need for starters, and is Noctua an option? I noticed that some fans have a constant full speed, others are controllable. Relevant?

The operating system
So I really dislike El Capitan. I'm currently on Yosemite 10.10.5 and don't really feel like going any further because with every update, something I really need and use has been broken. Buyer's guide only lists Mountain Lion and El Capitan for systems, so can I have Yosemite? My Mini came with Lion but no CD as I recall, and every update since then was downloaded from Apple as y'all know. Apple has removed Yosemite from the store so how would you actually acquire it now?

Graphics
It's known that the integrated Intel graphics cards included in most Macs have been somewhat incompatible with 3D stuff. In my experience, 3D was either very slow, plain incorrectly rendered or completely non-working even when the "requirements" listed by some software or game were met, in terms of memory and processor power.
I'm not going to do flash animations or serious 3D scenes, but if every once in a while I might want to boot in a Windows to play a non-online game or make a simple 3D scene that can actually get rendered as it's supposed to, are there some graphics cards that I should avoid when choosing, to avoid the same old crippled 3D? I'm pretty sure that all of the listed ones are fine with still image work so that's not a subject of worry. Resolutions might be a limiting factor though. I know that I will be using at least one regular sized monitor and one larger, possibly even a TV screen as a desktop extender. Currently both, thunderbolt and HDMI slots are being used by monitor screens.

Audio / motherboard
Do motherboard integrated / individual sound cards automatically support MIDI? I think external cards are either firewire or USB, the latter one not that endorsed. With Mini's sound card, latency becomes an issue very easily but the worst thing is when the computer simply fails to play it back and you get pops and audio dropouts. But what part of the computer is truly responsible for the quality of these, is it a processor + RAM issue more than a sound card issue? I have ways to avoid latency, but the dropouts are a terrible bottleneck. If the hard drive is also a crucial part of this, if I use an SSD as a scratch disk for audio recording for example, does it wear the disk out excessively fast?
If software allows scratch disk to be different than where the application is installed and where the project files exist, then at least it probably shouldn't be the very same SSD as the boot drive...

 

[Kazbah]

You are asking a lot of things so let's address a few quickie.

Can you keep going on Yosemite instead of El Cap ? Yes, but ..
It is possible that your DAW manufacturer does not support your DAW software on Yosemite
Don't expect to get drivers for any Pascal based GTX (GTX1060/GTX1070/GTX1080/GTX Titan X)
Apple has removed Yosemite from the store so how would you actually acquire it now? -> Not sure that I am allowed to answer this ...

Quietude
You have it all wrong on the mechanics of it. Number of fans is not the deciding factor.. cooling effiency is.
Of course you can install Noctua fans, I do love them. I am a quiet freak too and the loudest fan in my build is the one that it built into the power supply. Will try to give additional pointers in a separate post ...

Do motherboard integrated / individual sound cards automatically support MIDI? If you mean playback MIDI .. that is a fonction of the Operating System. MIDI is not sound but info on how to make it.

is it a processor + RAM issue more than a sound card issue? All of the above, the weakest link...

 

[Kazbah]

Quietude rules of thumbs :

Airflow : You want air to go thru your build as unobstructed as possible in a straight path, this improves cooling effiency and reduce turbulence, turbulence = noise.
More moving parts = more noise. Thus the more fans you have more noise you produce.
All other things being equal, a bigger fan will displace more air than a smaller fan at the same RPM. Thus providing more cooling power. In other words, a bigger fan will move more air without inducing much more noise. Or you can reduce speed from a bigger fan (thus reducing noise) to get same effiency of a smaller fan.

 

[pastrychef]

In addition to what Kazbah has recommended, try avoiding the use of too many different sized fans running at different RPM. The more effective your heatsink is, the less your fans will have to work.

 

[trs96]

@R77 If you have ever downloaded Mavericks when it was free starting back in Oct. 2013 you can download it again under your purchased tab from the Mac App Store. If you didn't get it when it was free you're out of luck as Apple doesn't sell it. I believe they are only selling Snow Leopard, Lion and Mountain Lion.

Noctua fans will work well for a silent build, you can even use the LN adapters to make it as quiet as possible. They are not in the Buyer's Guide but that doesn't mean you can't use them. Everyone has different preferences for color, brand, LEDs etc. and most cases come with fans pre-installed so there is no need to put any fans in the Buyer's Guide.

 

[kiiroaka]

The HDDs of my Mac Mini '11 are falling apart and I've been considering building my own because the perfect Mac for me doesn't exist.

Why not start by replacing the HDD, or replacing the HDD with an SSD?

That would give you a little more breathing room as you do in-depth research for your Ultimate MAC; and it allows you to keep adding to the savings account so that you can buy not only the better stuff, but also more of it, like going with 64GB of RAM instead of 16G or 32G. Since nVidia card prices are falling chances are you can get a better deal 30 days from now, and the 1070 and 1080 might be supported by then; who know? (Rhetorical).

As far as fans go, always try to get a case that can take 140mm, or larger, fans. If the case comes with sleeve fans - throw them out immediately, especially if they are mounted horizontally. Never buy a PSU with a horizontally mounted sleeve fan.