On Thu, 2022-03-10 at 22:40 +0000, Patrick O'Callaghan wrote: > On Thu, 2022-03-10 at 11:13 -0800, Samuel Sieb wrote: > > On 3/10/22 02:47, Patrick O'Callaghan wrote: > > > On Wed, 2022-03-09 at 11:25 -0800, Samuel Sieb wrote: > > > > On 3/9/22 02:44, Patrick O'Callaghan wrote: > > > > > Thanks for the detailed info. My current SSD is a Samsung 860 > > > > > EVO > > > > > (2TB) > > > > > so for comparison I did this: > > > > > > > > > > $ time dd if=/dev/zero bs=1G count=23 of=Big > > > > > 23+0 records in > > > > > 23+0 records out > > > > > 24696061952 bytes (25 GB, 23 GiB) copied, 14.9873 s, 1.6 GB/s > > > > > > > > > > real 0m15.087s > > > > > user 0m0.000s > > > > > sys 0m14.640s > > > > > > > > > > However that's clearly not a reflection of actual I/O speed > > > > > as > > > > > the > > > > > writes will have been cached. > > > > > > > > You can use "conv=fdatasync" to make sure all data is written > > > > before > > > > giving the final result. > > > > > > Didn't seem to make a difference: > > > > > > $ time dd if=/dev/zero bs=1G count=23 conv=fdatasync of=Big > > > 23+0 records in > > > 23+0 records out > > > 24696061952 bytes (25 GB, 23 GiB) copied, 15.3153 s, 1.6 GB/s > > > > Are you using btrfs with compression enabled? > > Btrfs in the default F35 configuration, so no compression.
Oops. It actually has "compress=zstd:1" in the fstab line. Apologies. That completely invalidates the numbers. poc _______________________________________________ users mailing list -- users@lists.fedoraproject.org To unsubscribe send an email to users-le...@lists.fedoraproject.org Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/ List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines List Archives: https://lists.fedoraproject.org/archives/list/users@lists.fedoraproject.org Do not reply to spam on the list, report it: https://pagure.io/fedora-infrastructure
