On Fri, Mar 06, 2020 at 01:11:05PM +0100, Thomas Seeling wrote:
> Hallo,
>
>
> I did some comparing of build times.
> Building was done on an older i5-6500 with 16 GB RAM, SATA harddisk and SSD.
>
> 9.1 build on SSD:
> The SBU unit value is equal to 117 seconds.
> Total time required to build the system: 79.6 SBU
>
> 8.3 build on HD:
> The SBU unit value is equal to 107 seconds.
> Total time required to build the system: 205.7 SBU
>
> 9.1 build on HD:
> The SBU unit value is equal to 107 seconds.
> Total time required to build the system: 294.9 SBU
>
>
> I'm not surprised about the speed difference but I wonder why the SBU is
> bigger for the SSD build? I was using the same jhalfs configuration file
> for the latest 9.1 build.
>
> Tschau...Thomas
> --
The SBU in LFS is related to the _host_ system (which is why for my
measurements in BLFS I rerun the calculation after booting the new
system). In general, the SBU gets slower, both from toolchain
changes and from kernel changes.
But for your SSD I'm guessing that you might not be using fstrim
(either manually, or the ',discard' option in the fstab), and
therefore writing a new block means it has sufficiently filled up
that it needs to shuffle things about.
Also, if the partitions are misaligned (I forget the details) an SSD
can be slow.
ĸen
--
#define THE_TRUTH_AND_THATS_CUTTIN_ME_OWN_THROAT true
Al Viro, complaining about a 'TRUE' macro in staging
--
http://lists.linuxfromscratch.org/listinfo/lfs-support
FAQ: http://www.linuxfromscratch.org/blfs/faq.html
Unsubscribe: See the above information page
Do not top post on this list.
A: Because it messes up the order in which people normally read text.
Q: Why is top-posting such a bad thing?
A: Top-posting.
Q: What is the most annoying thing in e-mail?
http://en.wikipedia.org/wiki/Posting_style
