EXT4/Btrfs/XFS/F2FS Benchmarks On Linux 3.17

[Michael]

why are all btrfs benchmarks here using mount option space_cache?
as far as i know this is a very bad idea on ssd, not only regarding their life time but it also should'nt yield any performance gain on them if not even make things slower.

Stock mount options were used for each file-system.

[nanonyme]

Honestly, I have no idea where you guys get tearing with blob, I've been using multiple cards from 8800 to 670 and never got any unexpected tearing with the blob. Maybe someone needs "X: Drivers and Compositing 101"?

There's been a lot of debate on this and iirc it resulted mainly in that whether or not you get tearing is based on luck with regards to GPU etc and whether your eyes just happen to pick it up

[mike4]

My Asus GTX770 on Ubuntu/Unity is in a recent test about 18% faster with x-plane than on Win8.1 or OSX.
Needless to say that it also looks as good.

[magika]

It's a longstanding problem with the Nvidia blob, I'm using driver version 340.24.

Honestly, I have no idea where you guys get tearing with blob, I've been using multiple cards from 8800 to 670 and never got any unexpected tearing with the blob. Maybe someone needs "X: Drivers and Compositing 101"?

[kenjitamura]

I also use nouveau with my GTX 770, as I don't play games under Linux and couldn't get the Nvidia driver to stop tearing under KDE.

You tried going into the Nvidia X Server Settings and changing the PowerMizer "Preferred Mode" settings from "auto" to "Prefer Maximum Performance"?

Only thing that severely reduces/eliminates tearing for me with my GT 640. It's a night and day difference in tearing for me just changing that one setting when I watch videos in VLC or SMPlayer. It's a longstanding problem with the Nvidia blob, I'm using driver version 340.24.

[geearf]

why are all btrfs benchmarks here using mount option space_cache?
as far as i know this is a very bad idea on ssd, not only regarding their life time but it also should'nt yield any performance gain on them if not even make things slower.

I am curious, why would space_cache be bad for an ssd performance?

[a user]

why are all btrfs benchmarks here using mount option space_cache?
as far as i know this is a very bad idea on ssd, not only regarding their life time but it also should'nt yield any performance gain on them if not even make things slower.

[jwilliams]

The main feature of btrfs is that it hashes all the files, so that it can detect bitrot and if in a raid... be able to repair it. Hashing the files takes time. Its a trade off. Somewhat slower file reads/writes for a more secure filesystem vs speed.

The time to compute (or check) the hash has insignificant effect on the speed of btrfs. The time to read and write the hash metadata has only a small effect.

The hashing is not the reason btrfs is usually slower. Most of it has to do with the COW nature of btrfs and resulting fragmentation (although in a few cases, COW will outperform non-COW filesystems). Some of it has to do with btrfs still not being well optimized.

Also, assuming he has not changed the IOMeter fileserver access pattern benchmark, the fio tester benchmark is doing 512 Byte IOs, which are an especially weak spot for btrfs.

[vivo]

The main feature of btrfs is that it hashes all the files, so that it can detect bitrot and if in a raid... be able to repair it. Hashing the files takes time. Its a trade off. Somewhat slower file reads/writes for a more secure filesystem vs speed.

I will take that any day over slightly more speed. I am using btrfs on my home server in RAID 1 exactly for that reason (with an ext4 backup and CrashPlan, just in case). I considered ZFS, but its non-nativeness,
RAM-chewing feature and my server's lack of ECC put me off. I also only have 8GB RAM, and I do run VMs as well.

On my desktop, I again use btrfs, but because I keep telling myself that I will start using its snapshot capabilities for my desktop.
Having it on an SSD, I cannot feel the performance difference compared to ext4. I also use nouveau with my GTX 770, as I don't play games under Linux and couldn't get the Nvidia driver to stop tearing under KDE.

I also do a fresh install on my desktop every couple of months, and that also includes a fresh /home partition (all data I want to keep is on the server), so I don't mind if btrfs bites my desktop every now and then.

[ua=42]

The main feature of btrfs is that it hashes all the files, so that it can detect bitrot and if in a raid... be able to repair it. Hashing the files takes time. Its a trade off. Somewhat slower file reads/writes for a more secure filesystem vs speed.