SLI does no good for GPGPU. Cycles will send render buckets to every GPU you have installed. SLI is a game technology, so you do not need to necessarily worry about if the motherboard you’re using will support it unless you want to use it for pretty substantial gaming.
two 980ti cards will place you squarely in one of the fastest GPU render benchmarks, and may very well be overkill. If you can afford it, go for it. But I’d install one and see if that’s sufficient.
If the system is well designed, liquid cooling is not neccesary unless you’re going for silent (or overclocking). As for lights and windows, whatever. If making your computer look like it should accompany bad techno at a 90s rave is your thing, go for it. Maybe add a spoiler too?
Bear in mind though, if you have two fans that cost the same but one has silly LEDs, chances are the one without will be better built. So if you have a $60 budget for cooling, some of that $60 is going into LEDs, which won’t provide any real benefit in terms of airflow, silent operation or build quality. Same with windows. You could spend $200 on a well engineered case, or you could spend $200 on a case with a window. But again, some of the money could have gone into air ducts or build quality would have gone into that snazzy window.
You could just say, oh, well I’ll just add more money onto my budget to get these snazzy things. At which point I’d why not add more of a budget to get even nicer components?
Silent is nice, though my system is plenty quiet and manages to run cooler than most I’ve seen online. Though, some of this might be a result of slower individual cores or being a Xeon architecture.
On startup it tests all the fans, so it can get plenty loud, though I have never heard it running at full RPM otherwise.
Just don’t fall into the whole “negative pressure” thing. People who advocate this failed physics class. The point of a fan is to provide thermal energy somewhere to go, not to “suck heat off” components. It’s important to have good airflow between an intake and an exhaust. If you’re worried about dust, get a can of duster!
Some, if not many gamers think they know a lot more than they do about technology. They tend to believe everything from CES and will often advise some pretty goofy shit. You also never know who you’re talking to online, and there is a good chance it’s a zit-faced kid who thinks slapping together some New Egg components makes him “good with computers” (after all, that’s what Grandma always says).
I’d be extremely careful at places like Tom’s Hardware or Linus Tech Tips. Trusting Linus the Tech Tool videos should be a call for questioning in itself.
I have never had a problem with Windows 10, and I have never used Windows 7. As far as I can tell the big thing people complain about with Windows lately is that they changed the start menu, which seems kind of silly.