After loading Fedora 19 as in my previous post , battery runtime has almost doubled compared to the previous ChrUbuntu 64-bit. This is consistent over the past weeks, with both the stock 3.4 kernel and a custom built 3.8 kernel. That’s a good reason if you want to run 32-bit than upgrading to 64-bit.
One of my friend who designs hardware for a living tells me that’s because now the software is using half the memory as before. That translates to about half the power consumption in the memory subsystem. That makes sense. It’s interesting as it looks the other subsystems in the hardware does not consume much power.