Times to build just devel/llvm50 via poudriere-devel: Pine64+ 2GB, RPi3, RPi2 V1.1

[Ian Lepore]

On Fri, 2018-01-05 at 00:40 +0100, Andreas Schwarz wrote:
> On 04.01.18, Mark Millard wrote:
> 
> > 
> > eMCC performance notes:
> > The rpi3 can get between 10 MiByte/s and
> > 12 MiByte/s, while the Pine64+ 2GB can get
> > between 5 MiBytes/s and 6 MiBytes/s, from
> > what I have observed.
> Unfortunatly the DiskIO (to SD Card) of the Pine64 is very slow 
> in comparsion to RPI2B (or RPI3).
> 
> root at rpi2b:~ # dd if=/dev/zero of=/var/zero.img bs=1m count=1024
> 1024+0 records in
> 1024+0 records out
> 1073741824 bytes transferred in 80.823823 secs (13284967 bytes/sec)
> 
> root at pine64plus:~ # dd if=/dev/zero of=/var/zero.img bs=1m count=1024
> 1024+0 records in
> 1024+0 records out
> 1073741824 bytes transferred in 383.600722 secs (2799113 bytes/sec)
> 
> Both devices running r327391 with without any debugging, INVARIANTS, 
> etc.. Used SD Cards: Samsung MB-MGBGB SDHC 32GB
> 
> Mark, can you perform the write test with your eMMC to MicroSD 
> Adapter?
> 
> -asc

It used to be that clang used files in /tmp to pass results between
stages of the compile whereas gcc used pipes.  I'm not sure if that's
still true, but if it is, then using tmpfs for /tmp should improve
compile times and remove much of the sdcard performance impact.

-- Ian