How is GNU `yes` so fast?

Re:How is GNU `yes` so fast? by du_bing on Tuesday June 13, 2017 @05:44AM (#14543738)

I run the command `yes | pv > /dev/null` on my MacBook Pro, it's only 37m/s, is this normal? I am not familiar with the command.

[ Parent | on HN ]

Re:How is GNU `yes` so fast? by likelynew on Tuesday June 13, 2017 @08:28AM (#14544248)

I am getting 26 MiB/s using native yes, and 620 MiB/s using GNU yes in macbook air.

[ Parent | on HN ]

Re:How is GNU `yes` so fast? by kjensenxz on Tuesday June 13, 2017 @05:57AM (#14543784)

From the OP:

>OS X just uses an old NetBSD version similar to OpenBSD's >NetBSD's is 139MiB/s, FreeBSD, OpenBSD, DragonFlyBSD have very similar code as NetBSD and are probably identical,

It really depends on how fast your memory and processor are. Everything there was benchmarked with an i7-4790 with DDR3-1600, and very very little running in the background.

[ Parent | on HN ]

Re:How is GNU `yes` so fast? by qb45 on Tuesday June 13, 2017 @06:08AM (#14543817)

Two orders of magnitude difference can't easily be blamed on CPU, in this case it depends on how optimized yes is. I have some older version of coreutils on one machine here and performance is similarly abysmal.

[ Parent | on HN ]