Re: compared filesystem performance, was Re: 10GBit network performance on OpenBSD 6.4
> totally agree, Anatoli could you please compare ? Will try to make tests these days + will attach dmesg. Anyway, without a FS (sequentially writing to a raw device) we'd be testing just the sequential speed to a raw device, not even to a partition. I think this would be a practical maximum possible performance for that device, not a real-use scenario. But combined with other tests this could be an interesting stat to find the bottleneck. *From:* Chris Cappuccio *Sent:* Tuesday, April 09, 2019 10:36 *To:* Gwes *Cc:* Chris Cappuccio , Anatoli , Misc *Subject:* Re: compared filesystem performance, was Re: 10GBit network performance on OpenBSD 6.4 gwes [g...@oat.com] wrote: That doesn't answer the question: if you say dd if=/dev/zero of=/dev/sda (linux) /dev/rsd0c (bsd) bs=64k count=100 what transfer rate is reported totally agree, Anatoli could you please compare ? That number represents the maximum possible long-term filesystem performance on that drive. you mean non-filesystem?
Re: compared filesystem performance, was Re: 10GBit network performance on OpenBSD 6.4
gwes [g...@oat.com] wrote: > > That doesn't answer the question: if you say > dd if=/dev/zero of=/dev/sda (linux) /dev/rsd0c (bsd) bs=64k count=100 > what transfer rate is reported > totally agree, Anatoli could you please compare ? > That number represents the maximum possible long-term filesystem > performance on that drive. > you mean non-filesystem?
Re: compared filesystem performance, was Re: 10GBit network performance on OpenBSD 6.4
On 04/08/19 19:29, Chris Cappuccio wrote: gwes [g...@oat.com] wrote: What is the rated transfer rate of the SSD you're using to test? SATA 3 wire speed is 6G/sec and realistically 500MB/sec raw rate is near the top. Anything over that is an artefact probably from a cache somewhere. He's using NVMe with its own DRAM cache, which should perform higly. There is a limiter somewhere, it seems. That doesn't answer the question: if you say dd if=/dev/zero of=/dev/sda (linux) /dev/rsd0c (bsd) bs=64k count=100 what transfer rate is reported That number represents the maximum possible long-term filesystem performance on that drive. There are other non-filesystem overheads which have to be excluded before you can be sure that the differences are truly the filesystem code and algorithms without cache differences.
Re: compared filesystem performance, was Re: 10GBit network performance on OpenBSD 6.4
gwes [g...@oat.com] wrote: > > What is the rated transfer rate of the SSD you're using to test? > SATA 3 wire speed is 6G/sec and realistically 500MB/sec raw rate > is near the top. > > Anything over that is an artefact probably from a cache somewhere. > He's using NVMe with its own DRAM cache, which should perform higly. There is a limiter somewhere, it seems.
