[revelio]

The author sounds a bit scared. Maybe the recent wave of "we can save $$$ by leaving AWS" articles have them rattled?

Yes, multi-tenancy and improved hw utilization can save money ... for Amazon. That's of no use if they lack sufficient competition and just capture the savings as profits. Then you're just wasting time on debugging weird contention issues and cloud cost optimization consultants so Bezos can get richer.

The profit margins on AWS are so huge that even though you they can binpack better it often doesn't matter, you're going to still save money by going to either a cheaper cloud or using your own HW (or renting your own dedicated HW). The savings from multi-tenancy are drowned by the added costs.

One intriguing model that might be worth exploring is micro-clouds. In that model there's a kind of clearing market, and users with strong diurnal cycles and not many batch jobs can re-sell their CPU capacity at night to other users. They just implement some Lambda-ish API and configure the kernels/hypervisors to always prioritize their own jobs over guests. The guests don't care because they're getting the resources cheap, for the company the additional income offsets the cost of their own machines and the market takes a cut. The difference vs today's cloud models is it's more decentralized and the "cloud provider" is really just a match maker, so it's easy to set up competitors and margins would be low.

[eecc]

that'd be cool but quite improbable until exploits like RowHammer, Meltdown and Spectre can be reliably ruled out.

[ElevenLathe]

Even if those were sorted, you probably want to hold out for homomorphic encryption. The threat model of Amazon having all your data is much different from the threat model of anyone willing to bid cheaply enough on a lambda execution having it. OTOH in the latter case, we can probably expect three letter agencies all over the world to be generously subsidizing our compute (for example, by reselling GovCloud at a loss).

[revelio]

Those problems affect cloud providers too.

BTW modern CPUs support the creation of RAM-encrypted VMs with remote attestation, so you can lower the trust needed in the targets by a lot. That said there are lots of companies that are known quantities, have verifiable brands and may even be considered more trustworthy than the big clouds in some cases because they're local firms.