# Wanted: howto on building a 3.2 realtime kernel

## more10

There is a lot of information on the net regarding building a realtime kernel, but its all outdated. 

I am very new to gentoo and would appreciate all help I can get on configuring the 3.2 kernel with realtime patches.

My goal is to build an audiophile gentoo music player, so I am not interested in the pro audio stuff.

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## i92guboj

I can only point you to kernel.org. The patches are there.

http://www.kernel.org/pub/linux/kernel/projects/rt/

However, I wonder what's the problem that you are tryin to solve. You don't need this to play audio files. You need real time, for example, when you are recording a voice or a guitar over a previously recorded mix and you want to hear that voice at the same time, while recording it.

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## xaviermiller

by the way, rt-sources are in Portage  :Wink: 

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## more10

But there are gentoo sources, sys-kernel/rt-sources.

I don't know if I really need realtime, but I want to try. Since I am an audiophile I will go to extreme lengths trying to improve my system  :Smile: .

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## xaviermiller

Hello,

Realtime is absolutely not needed for audio playback. It is only needed when you need deterministic time response. Not the fastes time response, but a maximum delay.

RT is useful for musicians who need to have controlled latency. But I don't think audiophiles need a RT kernel, they only need that the sound streams are uninterrupted, which is 99,9% the case.

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## more10

Its the last 0,1% I want  :Smile: . 

It is quite useless to argue with an audiophile what he needs. What he wants is more inportant than what he needs. That is what identifies an audiophile.

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## i92guboj

 *more10 wrote:*   

> Its the last 0,1% I want . 
> 
> It is quite useless to argue with an audiophile what he needs. What he wants is more inportant than what he needs. That is what identifies an audiophile.

 

Whatever. But if anything, this is going to harm you, instead of helping, even if for a very slight margin.

What you need is responsiveness in multitasking. That's the opposite of what rt aims to.

A typical desktop system is tuned so you can use many things at one in a fashion that none of them will be starved in which regards cpu time. You probably don't want gaps in between the tracks of your playlist if you are enabling visualizations in your player, do you?

rt on the other side concentrates on making uninterruptable things like jackd so the sound latency is a low as your hardware permits, often in detriment of things like frontends, the desktop, the visuals, or simply, playlist handling (which is a thing that will be done by your frontend, not by your rt jack audio sound daemon), etc.

Probably, in a modern system using one or the other kernel is not going to change the perceived interactiveness, unless you hit a bug in jackd (not that that's too difficult though). But, again, rt is conceptually the opposite of what you want. Anyway, it's your time, so you can "invest" it in whatever you want. If you say helicopters to drive are better suited than cars for the highway, you might be wrong, but you are absolutely in your right to think so.  :Laughing: 

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