Let’s say we’re spending $1 million on hardware hypothetically with the swap setup.

At that price point, either we use swap and let the kernel engineers move data from RAM to disk and back, or we disable swap and need user space code to move the same data to disk and back. We’d need to price out writing & maintaining the user space implementation (mmap perhaps?) for it to be fair price comparison.

To avoid SSD wear and tear, we could spend $29 million a year more to put the data in RAM only. Not worth!

(We rent EC2 instances from AWS, so SSD wear is baked into the pricing)