Hacker News new | ask | show | jobs
by my123 2173 days ago
(disclaimer: I work at AWS)

Hello,

There definitely is that power use advantage.

Those tests are pathological cases because of bugs, and aren't representative of the performance of the hardware. (for that one I suspect that ARMv8.1-A atomics weren't used in compiler options...)
1 comments
jeffbee 2173 days ago
Well, the listed GCC options do not specify microarchitecture for either ARM or x86. So it's probably a k8-compatible binary on the top line, too. I'm also not sure why atomics would be important in a single-client mysql benchmark. Either way, the risk that your toolchain doesn't automatically do the right thing is one of the costs that keeps people from jumping architectures.
link
my123 2173 days ago
GCC 10 onwards are finally able to get and use Arm atomics at runtime on arm64.

> I'm also not sure why atomics would be important in a single-client mysql benchmark

They are because exclusive load & store operations are quite expensive on Arm, even if you actually just run an ST workload.

link
jeffbee 2173 days ago
Let me ask you then, since you seem plugged in: if the win is there, why can't I buy RDS on Gravitron?
link
datasage 2173 days ago
I presume this has to do with support for ARM with the database software.

PostgreSQL appears to have had ARM support for sometime. Mysql only added it with 8.0. As far as the other database options are concerned, ARM isn't even supported yet.

link
imtringued 2172 days ago
Ok, so why would I use an architecture that barely has any software support?
link