At work, we have a lot of basic servers. These basic servers are 1U rack servers, with unexciting amounts of disk bays, RAM, and CPU performance, because we buy them to do straightforward jobs (for example, much of our mail system hardware is basic servers ). Right now, these are all x86 machines, but like a lot of people I'd love it if the x86 architecture had real competition (even if returning to the days of a multi-architecture Unix environment wouldn't necessarily be fun). However, these days I don't think we're likely to see basic 1U ARM servers that we're interested in, and why that is comes down to modern hardware and modern basic server power usage.

At this point, the largest hardware difference between a reasonably performing basic x86 server and a reasonably performing basic ARM server will be the CPU (and surrounding chipset). Everyone uses the same RAM, the same PCIe busses, and quite possibly the same supporting chips for things like Ethernet and so on. And everyone is going into the same rack form factor 1U boxes with very similar power supplies and physical sizes.

My impression is that at the basic end, a comparably performing ARM server CPU is going to cost about the same as an x86 CPU (assuming you can get the former). My further impression is that the ARM CPU isn't going to have a significant power and heat advantage under normal usage, especially since modern basic servers seem to have pretty low power consumption in general ( also ). This means that I'd expect a basic ARM server to cost about the same as a basic x86 server and generate about the same heat and power load. Even if the ARM CPU is a bit cheaper, it's only one component out of many (and let's ignore the current inflation of RAM prices).

More powerful ARM servers (such as those used by the cloud vendors, or the ones with powerful CPUs that you can theoretically buy) can have a real advantage in some situations over x86 servers, so if you use some of those you might want some basic ARM servers for lighter weight work on the same architecture. But if your environment is otherwise free of ARM servers, and the basic ones cost the same as x86 servers, and maybe you have a bunch of x86 servers already, there doesn't seem to be much to attract people to ARM servers.

I feel a bit sad about this, because there's part of me that thinks it would be nifty to have some ARM servers around, but it certainly makes life easier to only have one CPU architecture for in our Unix machines. x86 CPUs are perfectly good, and these days all of the other parts are basically the same.

(Given this, I'd be somewhat surprised if very many vendors even offered basic ARM servers, especially for a competitive price. There are people selling 1U ARM servers but they're high core count things and I assume they cost accordingly. I don't know if anyone is making ARM servers in the 16 to 32 core range (or less), although there are definitely ARM CPUs that are that small. Although even the larger CPUs can have issues , although apparently that's on an older, lower performing ARM CPU.)

PS: In the past I've read that x86 CPUs no longer really have a power penalty because of their architecture; my impression is that this is less because dealing with the weird x86 stuff got more efficient and more that these days it's dwarfed by everything else going on in your typical complex, out of order cores.