# Makeopts [/solved]

## rottingdead

Hello, I've been using MAKEOPTS="-J3" Would it harm the system if I tried -j4?  I have an Intel Core2 Duo, and already realize I need -j3, but to me, I seen no differentce between -j2 and -j3, I know it supports how many compilations emerge can do, was just curious here, trying to figure out a way to make the system compiler faster.

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## Hu

It is very unlikely that you will damage your system in a permanent way.  However, depending on other factors, using -j4 might be overall slower than -j3.

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## rottingdead

 *Hu wrote:*   

> It is very unlikely that you will damage your system in a permanent way.  However, depending on other factors, using -j4 might be overall slower than -j3.

 

Aaaah, so, it wouldn't make sense to use j4?  Then how about j1?  LOL, I bet that would make it even slower than j3.

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## Hu

I said it might be overall slower.  I do not have enough information about your system to say that it will be or will not be overall slower.

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## Veldrin

The makeopts (or more [percisely the jobs for make) are set usually to number of processor cores + 1.

The idea behind is simple, create enough jobs to occupy all cores, and keep one spare job, to fill the gaps.

Nowadays, I would not use -j1, unless you run into problems.

The other factor, is that each compile job consumes memory, thus if you are already tight on memory, lowering the amount of jobs can improve performance.

All that said, -j3 seems a good value for a core2duo.

just my .02$

V.

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## phajdan.jr

 *rottingdead wrote:*   

> Hello, I've been using MAKEOPTS="-J3" Would it harm the system if I tried -j4?  I have an Intel Core2 Duo, and already realize I need -j3, but to me, I seen no differentce between -j2 and -j3, I know it supports how many compilations emerge can do, was just curious here, trying to figure out a way to make the system compiler faster.

 

Just benchmark. If it's faster, stick to it, if it's slower, don't use it. More running processes means more loaded system, especially more memory and I/O contention. If there is no benefit, it could make the system slower.

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