# How to disable PAE



## JibJabM (Jan 30, 2020)

I'm trying to debug running FreeBSD i386 on a 32bit machine (Intel Core Duo U2500 @ 1.20GHz). I may do another post for this next... but to focus on the main question:

What config file and what option do I need to enter to disable PAE? It would be good to document this for both myself and others.

Every google search like "FreeBSD disable PAE" seems to lead me to these frequently asked questions. But that FAQ doesn't say HOW to enable or disable PAE (only how to enable it on a custom PAE enabled kernel... but not even where that configuration is set). A lot of the questions on that FAQ are awesome... but this one is pretty vague on actual details.


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## k.jacker (Jan 30, 2020)

Not that I really know the answer and I havn‘t even used i386 for a long time, but...
I guess you have three options:
1. look for kernel tunables e.g. with `sysctl -a | grep pae` to disable it
2. build a kernel without PAE
3. check your Computer‘s BIOS for an option to disable it


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## Maxnix (Jan 30, 2020)

According to the FAQ you linked, PAE is supported, disabled by default, and can be enabled compiling a new kernel with 
	
	



```
options PAE
```
 in its config file (4.1.3).
Am I missing something?


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## JibJabM (Jan 31, 2020)

Oh. Maybe it is disabled by default... I assumed it was enabled... and that it might solve my problem... Sorry to waste time, I misread.


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## SirDice (Jan 31, 2020)

Maxnix said:


> PAE is supported, disabled by default


Yep. To add to that, it was never enabled by default, you always had to explicitly enable it with a custom kernel.


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