Add read/write speed after finishing each file

[mathew0007]

It would be nice to have a speed reporting for each file, so a HDtune-like graph could be compiled externally for each GB written.
The reason I ask is that I would like to see speed changes for the entire drive.

I already see speed reporting during writing, I just want it also present after "OK"-ing each file.

[makefu]

I'd love to see the same for f3brew which currently does not show any output in the run except for Writing blocks from 0x0 to 0xee8bff... until finished

[AaronCompNetSys]

Honestly, this app is kind of useless to may people unless we know the write speeds are consistent and accurate. If a handful of blocks only wrote at 1Mbps then the card is trash and can't be used in any media device. We would never know if the issue happened in the middle of the f3write process.
I just had a card that I tested with f3, slow down during a drone flight, and I don't even know how to test a replacement card.
This app needs the ability to detect slow periods of write speeds, the same as FPS counters or CPDT Benchmark.

[ArturKlauser]

I was also hoping to find some option (like a verbose progress) that would document the writing speed of each file once the file is done. While watching the terminal, I noticed that the writing speeds of "real" and "fake" blocks on my flash seem very different - I guess it's easy to write fast if it just throws away the data. But USB sticks are getting up to very large "claimed" capacities (I'm testing one that claims to be 1TB), writing/reading of which takes on the order of 24 hours. And I'm not watching the terminal for that period of time, but would still like to be able to look at the terminal history later and see how the speed was behaving .

[Bzzz]

I second that.
The current generation of fake NVMe drives passes f3probe, but write speed falls off a cliff in f3write pretty soon. Having just a per-line output of speed would help tremendously documenting that behaviour

sudo f3probe /dev/nvme1n1
F3 probe 8.0
Copyright (C) 2010 Digirati Internet LTDA.
This is free software; see the source for copying conditions.

WARNING: Probing normally takes from a few seconds to 15 minutes, but
         it can take longer. Please be patient.

Probe finished, recovering blocks... Done

Good news: The device `/dev/nvme1n1' is the real thing

Device geometry:
                 *Usable* size: 3.64 TB (7814037168 blocks)
                Announced size: 3.64 TB (7814037168 blocks)
                        Module: 4.00 TB (2^42 Bytes)
        Approximate cache size: 0.00 Byte (0 blocks), need-reset=no
           Physical block size: 512.00 Byte (2^9 Bytes)

Probe time: 9.14s

After a 64GB write when I noticed it's no longer whizzing by, and a full 4TB trim (!?), this is what shows up:

sudo f3write /media/bzzz/fake4tb/
F3 write 8.0
Copyright (C) 2010 Digirati Internet LTDA.
This is free software; see the source for copying conditions.

Free space: 3.58 TB
Creating file 1.h2w ... OK!                             
Creating file 2.h2w ... 0.05% -- 367.31 MB/s -- 3:43:21
OK!                             
Creating file 3.h2w ... OK!                             
Creating file 4.h2w ... OK!                             
Creating file 5.h2w ... OK!                             
Creating file 6.h2w ... OK!                            
Creating file 7.h2w ... OK!                            
Creating file 8.h2w ... OK!                            
Creating file 9.h2w ... OK!                            
Creating file 10.h2w ... 0.27% -- 43.29 MB/s -- 24:02:28

[AltraMayor]

The just-merged pull request #271 adds the following per-file statistics: average, minimum, and maximum speeds.