Puppy Linux Discussion Forum

NeverThere · Joined: 24 Nov 2010 Posts: 18

Sorry if this sounds newbish.

Do all Puppies use the same kernel timer frequency? And if not, which speed is most commonly used?

1000Hz? 300Hz?

jemimah · Joined: 26 Aug 2009 Posts: 4309 Location: Tampa, FL

I think most of the kernels are tickless these days.

NeverThere · Joined: 24 Nov 2010 Posts: 18

Sorry for my lack of knowledge, but does that mean that Puppy would favor energy savings, and/or throughput, over responsiveness in heavier media apps?

Would setting a custom kernel to 1000 Hz produce better results for media players, or video game performance, at the cost of using more power?

Béèm · Posted: Fri 24 Dec 2010, 05:26 Post_subject:

The information you ask is basic for hardware working of a PC and isn't really a puppy question.

You could google to know more about how hardware works.

In short, the higher the frequency of the CPU the more power it needs.

Therefor laptops can be set, mostly through the bios to meet a balance between battery live and workability.

You don't say which puppy you use, which is a must, but there are puppy's which have a program: frequency scaling. The frequency for the CPU is adapted to user-defined settings.

NeverThere · Joined: 24 Nov 2010 Posts: 18

I'm referring to the kernel timer, and that timer's frequency, not the CPU clock.

- How fast should HZ be?
- How To determine Linux Kernel Timer Interrupt Frequency

Surely some of the Puppy maintainers custom compile their kernels, right?

trapster · Joined: 28 Nov 2005 Posts: 1966 Location: Maine, USA

Puppeee1.0 on EEEPC1005HA

NeverThere · Joined: 24 Nov 2010 Posts: 18

Are there any Puppies with a pre-emptible kernel, with the hz set to 1000 during the compile?

jemimah · Joined: 26 Aug 2009 Posts: 4309 Location: Tampa, FL

Fluppy is compiled PREMPT, with NO_HZ. NO_HZ adjusts dynamically depending on the needs of the scheduler. I think Puppy Studio also has a preempt kernel.

You really shouldn't need to worry about latency with a tickless kernel.
http://forum.soft32.com/linux/tickless-HZ-1000-throughput-advantage-ftopict494863.html

NeverThere · Joined: 24 Nov 2010 Posts: 18

Really?

I was told recently that when I compiled a Debian kernel that I should select PREMPT, and 1000hz. The tickless kernel thing was mentioned to be dependent on the hardware, with some older PCs actually running slightly faster without it. Minus the power saving efficiency of course...

They said 250/300 hz kernels were for server, or compiling, uses. 1000hz was mentioned to be better for multimedia performance like audio, video, games, xorg, or the desktop in general.

Would Fluppy run on older IBM PC desktops, or would the hardware drivers not be supported?

jemimah · Joined: 26 Aug 2009 Posts: 4309 Location: Tampa, FL

I know some people are successfully running it on older hardware. But all my test machines are less than 5 years old.

My understanding is the l0wt3ch did pretty thorough testing and Puppy Studio (with a similar kernel to Fluppy) far outperformed anything else in terms of latency - mainly just due to the lightness of the OS I suppose.

The only way to know for sure is to try it.

NeverThere · Joined: 24 Nov 2010 Posts: 18

I don't know...

If I had a laptop, I might give Fluppy a shot, but it's too tailored to hardware I don't have. Same for Studio, I need a Puppy with a kernel that favors low-latency desktop environments, video, games, emulators, etc... not sound.

It says right on the first page that isn't what Studio is for.

Does anyone know how I could recompile the latest Lucid kernel, changing only those two options? ie - PREEMPT, 1000hz for the kernel

The out-dated Puppy 4.3.1 runs decent on this, but Lucid 5.1 is a bit slow.

NeverThere · Joined: 24 Nov 2010 Posts: 18

Well, Fluppy fails at boot, and Studio (lite version) is monstrously slow.

Those are a no go for this old PC. Anyone know how to replace a kernel in of the pre-built puppy distros?

Béèm · Posted: Sun 02 Jan 2011, 05:19 Post_subject:

I found that the new born Teh gray puppy 053, recent announced wary 5.0 run snappier on my PC then Lucid

NeverThere · Joined: 24 Nov 2010 Posts: 18

Thanks for the recommendations. Wary runs the fastest out of the currently maintained Puppies I've tried. A bit light on available apps, but hey... Smile

One thing I noticed about it though is that a couple, or more, of the media apps seem to have unresolvable dependencies. At least the default Mplayer works like a charm.

I suppose that if nobody has the time/ability to tell me how to recompile a kernel for puppy with the RT tweaks, I'm plain out of luck.

I guess I'll use Wary until I finish building my minimal Debian install into a more moderate one.

Béèm · Posted: Mon 03 Jan 2011, 07:55 Post_subject:

Sent a PM to Barry Kauler to ask.