Haiku on EeePC 701 4G

I have an old 701 sitting around. I tried various flavours of Linux on it but it never really felt decently quick. Yesterday I loaded the latest nightly and so far it works perfectly - I might just end up using this old thing again.

The one problem I’m having is that I flashed on the 701 a hacked BIOS that de-underclocks the CPU to its original 900MHz (it’s downclocked to 630 in stock form). If I activate this option and run the CPU at full power, Haiku locks up during boot. It runs fine if I keep the option disabled.

I found this old thread -> https://www.haiku-os.org/community/forum/haiku_eeepc_701_some_questions_other_eeepc_users <- that touches the same problems, but it refers to topics on the old eeeuser boards that no longer exist.

Basically I need either the updated fixed-fan version of the other hacked BIOS that thread refers to, or some way to change the frequency from software after the system’s booted. I’ve zero experience with Haiku so I don’t really know where to start digging to get at the CPU settings.