All packages are build with -march=<cpu-set> and -O3. Some packages will not build with -O3, they will just be provided from the official repos as usual.
**Important**: Before you enable any of these repos, check if your system supports x86-64-v3. You can do that with `/lib/ld-linux-x86-64.so.2 --help`. If you don't check beforehand you might be unable to boot your system anymore and need to downgrade any package that you may have upgraded.
Example output snippet for a system supporting up to `x86-64-v3`:
```
Subdirectories of glibc-hwcaps directories, in priority order:
Replace `x86-64-v3` with your cpu-set. More information about all available options on [this gcc page](https://gcc.gnu.org/onlinedocs/gcc/x86-Options.html).
Currently, alhp.harting.dev only builds for `x86-64-v3` (list is subject to change).