# git diff timing oddity

3 messages from 2010-05-06 to 2010-05-06. Participants: Jay Soffian, Jeff King.
Thread: https://gitlist.dev/t/23713

## Jay Soffian, 2010-05-06 05:04

Subject: git diff timing oddity
Message-ID: <y2j76718491005052204qb6de9c26k58eb1550f1c5346f@mail.gmail.com>
URL: https://gitlist.dev/e/y2j76718491005052204qb6de9c26k58eb1550f1c5346f%40mail.gmail.com

```
git version 1.7.1, Mac OS X 10.6.3, largish repo (42K files, 35K
commits, well packed ~ 1GB). Difference between origin and HEAD is a
single commit.

$ time git diff --stat origin  >/dev/null

real	0m0.942s
user	0m0.713s
sys	0m0.223s

$ time git diff --stat origin  >/dev/null

real	0m0.944s
user	0m0.712s
sys	0m0.227s

$ time git diff --stat origin  >/dev/null

real	0m0.944s
user	0m0.712s
sys	0m0.225s

$ time git diff --stat origin HEAD >/dev/null

real	0m0.022s
user	0m0.006s
sys	0m0.012s

$ time git diff --stat origin HEAD >/dev/null

real	0m0.022s
user	0m0.006s
sys	0m0.013s

$ time git diff --stat origin HEAD >/dev/null

real	0m0.023s
user	0m0.006s
sys	0m0.013s

These should be identical commands, so why is the "origin HEAD" form
running an order of magnitude faster?

j.

```

## Jay Soffian, 2010-05-06 05:07

Subject: Re: git diff timing oddity
Message-ID: <u2x76718491005052207z252008c5sb0d3eafb4a50ada6@mail.gmail.com>
URL: https://gitlist.dev/e/u2x76718491005052207z252008c5sb0d3eafb4a50ada6%40mail.gmail.com
In-Reply-To: <y2j76718491005052204qb6de9c26k58eb1550f1c5346f@mail.gmail.com>

```
On Thu, May 6, 2010 at 1:04 AM, Jay Soffian <jaysoffian@gmail.com> wrote:
> These should be identical commands, so why is the "origin HEAD" form
> running an order of magnitude faster?

Because I'm an idiot. Three times I ran "origin" and thought I was
running "origin..". Sigh.

j.

```

## Jeff King, 2010-05-06 05:08

Subject: Re: git diff timing oddity
Message-ID: <20100506050836.GA11578@coredump.intra.peff.net>
URL: https://gitlist.dev/e/20100506050836.GA11578%40coredump.intra.peff.net
In-Reply-To: <y2j76718491005052204qb6de9c26k58eb1550f1c5346f@mail.gmail.com>

```
On Thu, May 06, 2010 at 01:04:18AM -0400, Jay Soffian wrote:

> git version 1.7.1, Mac OS X 10.6.3, largish repo (42K files, 35K
> commits, well packed ~ 1GB). Difference between origin and HEAD is a
> single commit.
> 
> $ time git diff --stat origin  >/dev/null
> 
> real	0m0.942s
> user	0m0.713s
> sys	0m0.223s
>
> [...]
>
> $ time git diff --stat origin HEAD >/dev/null
> 
> real	0m0.022s
> user	0m0.006s
> sys	0m0.012s
>
> [...]
> 
> These should be identical commands, so why is the "origin HEAD" form
> running an order of magnitude faster?

Isn't "git diff --stat origin" comparing against the working tree?

-Peff

```