> -----Original Message----- > From: linux-btrfs-owner@xxxxxxxxxxxxxxx <linux-btrfs- > owner@xxxxxxxxxxxxxxx> On Behalf Of Peter Becker > Sent: Friday, 23 August 2019 1:40 AM > To: Holger Hoffstätte <holger@xxxxxxxxxxxxxxxxxxxxxx> > Cc: Linux BTRFS Mailinglist <linux-btrfs@xxxxxxxxxxxxxxx> > Subject: Re: [PATCH v2 0/4] Support xxhash64 checksums > > Am Do., 22. Aug. 2019 um 16:41 Uhr schrieb Holger Hoffstätte > <holger@xxxxxxxxxxxxxxxxxxxxxx>: > > but how does btrfs benefit from this compared to using crc32-intel? > > As i know, crc32c is as far as ~3x faster than xxhash. But xxHash was created > with a differend design goal. > If you using a cpu without hardware crc32 support, xxHash provides you a > maximum portability and speed. Look at arm, mips, power, etc. or old intel > cpus like Core 2 Duo. I've got a modified version of smhasher (https://github.com/PeeJay/smhasher) that tests speed and cryptographics of various hashing functions. Crc32 Software - 379.91 MiB/sec Crc32 Hardware - 7338.60 MiB/sec XXhash64 Software - 12094.40 MiB/sec Testing done on a 1st Gen Ryzen. Impressive numbers from XXhash64. Paul.
