I’m curious as to what people are seeing in terms of I/O performance from the internal eMMC, I’m seeing that reads are significantly slower than writes which is unexpected.
Writes:
purism@pureos:~$ dd if=/dev/zero of=io-test-file bs=4096 count=250000 conv=fdatasync
250000+0 records in
250000+0 records out
1024000000 bytes (1.0 GB, 977 MiB) copied, 16.0372 s, 63.9 MB/s
Reads:
purism@pureos:~$ dd if=io-test-file of=/dev/null bs=4096 count=250000 iflag=direct
250000+0 records in
250000+0 records out
1024000000 bytes (1.0 GB, 977 MiB) copied, 59.1235 s, 17.3 MB/s
These results are consistently repeatable.
The phone in question is running Byzantium luks variant, although bench marking the crypto would suggest that it’s capable of encryption/decryption magnitudes faster than disk I/O so shouldn’t be a factor?
@Loki, I managed to find my post (I’m tired now to explain everything on how I’ve tested) yet creating test_eMMC_zero_data file of preferable size is important. Please follow this procedure that I made when I had more time, hope that helps:
Afterwards, when ready to use above created file (within that folder) you might like to take a look (proceed) with something as posted inside of my post #40, same thread. All actually based on @amosbatto request, his post #24.
I’d also like to see your Librem 5 eMMC performance results (therefore this post), sure, if you don’t mind.
Thanks for the links. I’m trying not to get too caught up in the details these days, this caught my eye as I was taking a baseline to compare with after changing the encryption on the root file system from LUKS1 to LUKS2 and upping the key size, but as dos has pointed out, I needed the oflag=direct in order for the read and write results to be comparable.