Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

What is the use of sysctl.d/99-powersave.conf for an SSD drive? #4

Open
adrfantini opened this issue Jan 27, 2017 · 5 comments
Open

Comments

@adrfantini
Copy link

Most of the content of sysctl.d/99-powersave.conf refer to delaying disk writes, which should be, if I'm not mistaken, not necessary on an SSD drive. Is this wrong? Did you do any testing?

Thanks

@Hjdskes
Copy link
Owner

Hjdskes commented Jan 27, 2017

That depends on what you mean with "not necessary", I suppose. If your goal is power saving, then you are probably correct in that it does not save as much power on an SSD as it does on an HDD (haven't tested how much of a difference, if any, it makes. I assume it would be negligible). However, less writing improves the lifespan of your SSD so in that sense you could deem it necessary (although, with modern SSDs, this is also not much of an issue anymore).

In any case, it won't hurt to have them listed. Most of the entries in that file are currently commented, too.

@adrfantini
Copy link
Author

adrfantini commented Jan 28, 2017 via email

@Hjdskes
Copy link
Owner

Hjdskes commented Jan 28, 2017

Still it wouldn't be bad to specify that the powersaving impact of those
changes are probably minimal for SSDs.

I'm planning on writing an in-depth blog post about these settings, in which I will definitely mention this. I'll add it to the README too.

I would think that with a modern SSD those settings are probably best left at the default values as the benefits are very limited, and you pay a small price in responsiveness and amount of data lost on a crash.

They are left at the defaults, except for vm.dirty_writeback_centisecs (which, I admit, is a leftover from the time where I did not have an SSD - I'll probably change it when I write that blog post). In this case I'd still like to keep them in, if only to notify others of their existence. I have not noticed a (however small) decrease in responsiveness nor (increased) data loss on a system crash. In any case, feel free to change the settings to whatever you prefer!

@adrfantini
Copy link
Author

adrfantini commented Jan 28, 2017 via email

@Hjdskes
Copy link
Owner

Hjdskes commented Jan 28, 2017

No problem, I appreciate the message!

Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
Labels
None yet
Projects
None yet
Development

No branches or pull requests

2 participants