[nine_k]

A GB of RAM only costs less than $10 if you are buying for your unpretentious gaming rig.

A GB of ECC server RAM costs more. An extra GB of RAM in the cloud can even cost you $10/mo if you have to switch to a beefier instance type.

[Roboprog]

How much does a MB of L-n cache cost?

I don’t have the answer, but you would want to measure dollars to buy it, and nanoseconds to refill it.

[projektfu]

That's true, if you're buying OEM ram for Dell or HP servers, it's more like $10-20/GB. However you can buy Crucial ECC DDR4 ram for $6/GB, so there's a hefty OEM markup.

[gowld]

$10/mo is far less than the cost of thinking about the issue at all.

[cryptonector]

Yes, but. Suppose you build a thread-per-client service before you realized how much you'd have to scale it. Now you can throw more money at hardware, or... much more money at a rewrite. Writing a CPS version to begin with would have been prohibitive (unless you -or your programmers- are very good at that), but writing an async/await version to begin with would not have been much more expensive than a thread-per-client one, if at all -- that's because async/await is intended to look and feel like thread-per-client while not being that.

One lesson I've learned is: a) make a library from the get-go, b) make it async/evented from the get-go. This will save you a lot of trouble down the line.