forza_user

I was surprised of the new attempt for performance profiles/device roles/hints when we already have a very good patch set maintained by kakra.

- https://github.com/kakra/linux/pull/36

- https://wiki.tnonline.net/w/Btrfs/Allocator_Hints

What do you think?

The mic of my XM5 picks up background chatter pretty much, making them difficult to use in calls in the office. The receiver hears my colleagues just as loud as my own voice. I am hoping improvements here. The poly headphones are lightyears ahead in this regard.

As for general noise, it is better, but I am annoyed that an ambient-like mode turns on during calls, negating much of the ANC for me.

What do you think of the new XM6? Worth the upgrade from XM5? What are objectively the very best ANC wireless headphones on the market?

24VDC is the most common supply for industrial electronics like PLCs, sensors etc. It is used in almost every type of industrial automation systems. 48VDC is also not uncommon for bigger power supplies, servos, etc.

https://www.siemens.com/global/en/products/automation/power-...

There is a patch for this. Hopefully it will be available in mainline kernels soon. https://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux....

The allocator hints only makes sense with at least two devices. Btrfs is metadata heavy, so offloading metadata to faster devices can make a big performance difference. For example a HDD combined with a small SSD or NVMe disk, you would set "data preferred" on the HDD and "metadata preferred" on the SSD/NVMe disk.

One advantage with these patches compared to using dm-cache, lvmcache or bcache is that everything is native Btrfs and fully compatible with non-patched kernels (though the 'hints' won't apply for new writes). Btrfs allows for adding additional devices to existing filesystems, so no mkfs and data-shuffling is needed. If you do not like the result, simply set default hint (type 0). You can then "btrfs device remove" your previously added SSD/NVMe devices.