Don't get me wrong, I still love the 1700. If you already have a 1700, then DO NOT upgrade to 3600 lol. But if you set out to build a new system, then 3600 is also a very good choice. Yes, it'll cost a bit extra. But you'll save on your light bills while pumping out more points and finish results more faster.
Boost clock is just a short burst of a single thread for a short period of time. For crunching, it doesn't affect us. What we want is what they're calling "game clock", all cores clock under load.

A friend of mine is running 4 x 3900x's on a single 850W Platinum PSU.
Upfront cost can be reduce if you're creative. Electric bills can be brutal if you can't find a good deal.

Those usually have weak VRMs with no VRM heatsink, I wouldn't trust those boards to run
a 24/7 load with any 6/8 core Ryzen.

The cheapest I use is the Gigabyte B450M S2H, it's pretty cool under load for an 1700/2700.

Top pic 3600, bottom pic 1700. Same project, same clock speed, same OS.
Ignore the big number, that 7 days worth of bunkering for the WCG's birthday race.Just look at the 17th and the 18th of November.

Mmmm, that's going overboard. A320 has limitations, but it's absolutely fine running a 1600 or 1700. I know because I'm running 3 1700s on A320 boards, 24/7, for months at a time, with no heat issues or any other issues whatsoever.

Now, that doesn't mean that A320 is a perfect solution for every use case. I had a very particular use case, where I was trying to get some serious crunching power, with new parts, at the lowest price possible. Any other use case? Absolutely, pay the 16% premium and get the better B350 or B450 boards, especially if you want to overclock, or if if you want to run a top of the line 2000 or 3000 series. But if you're not looking to upgrade for a long while, and you're looking to maximize the best-bang-for-the-buck value? It'll work

Also, VietOZ, thanks for the links! I've been wondering if something like these would work. It would be so much more convenient to buy one good PSU and split the power delivery than to buy one for each system. And so long as total power draw was only around half of the total rated power that the PSU could deliver, it would still maximize efficiency...

@Sheridon:
Yes, this time MIP gave the 3600 a bit more advantage. I'm running 5 MIP on 3600 + 7 MCM versus 3 MIP + 13 MCM on 1700. However, this wasn't the first time the 3600 has out done the 1700. During Thor challenge, I noticed the 3600 out gun the 1700 on Zika as well. Not only on WCG, on other projects during FB Sprints, same thing.
By same clock speed I mean I have them both running at 3.8ghz.