V3 with Arch slow FTP performance compared to V2 Debian?

[rampage]

Hi,

I noticed the FTP(proftpd/vsftpd) running on V3 archlinux is a lot slower than the FTP speed on a V2 Debian.
Both reading files from same model USB drivers.

On V3 Archlinux:
with files small around 100MB, transfer rate is around 20MB/s
bigger files can only do 15MB/S.

On a V2 with Debian:
any files can always transfer at 29.9MB/S which I think it's limited by the USB port.

So is it the slow CPU bottleneck on V3 caused this? or configuration/software related?

[WarheadsSE]

It might partially be a CPU bottleneck, although I can hit better speeds than that via samba, so it almost seems like a configuration issue.

[rampage]

it could be either the cpu or the USB IO chip/

On V3 with ALARM
$this->bbcode_second_pass_code('', 'hdparm -Tt /dev/sdb1

/dev/sdb1:
Timing cached reads: 434 MB in 2.00 seconds = 216.85 MB/sec
Timing buffered disk reads: 76 MB in 3.06 seconds = 24.85 MB/sec
')
24.8MB/s is the max speed I can get if the file is smaller than 200MB, drops to ~15MB/s while the file getting bigger.

on V2 with Debian
$this->bbcode_second_pass_code('', '
hdparm -Tt /dev/sdb1

/dev/sdb1:
Timing cached reads: 524 MB in 2.01 seconds = 261.21 MB/sec
Timing buffered disk reads: 90 MB in 3.02 seconds = 29.80 MB/sec
')
I can always get 29MB/sec speed on this box using FTP.

The attached external hard drives are same model.

Time to try the internal SATA port I guess.

[WarheadsSE]

Sounds like the memory might difference might be coming into play.

[karog]

Interesting to see others disk speed results. Here are mine, fastest to slowest on buffered times:

pogo B01 (V3) alarm SATA WD5000BPKT ext3
$this->bbcode_second_pass_code('', '
# hdparm -Tt /dev/sda2

/dev/sda2:
Timing cached reads: 570 MB in 2.01 seconds = 284.22 MB/sec
Timing buffered disk reads: 196 MB in 3.00 seconds = 65.31 MB/sec
')

pogo E02 (V2) alarm USB seagate ext4
$this->bbcode_second_pass_code('', '
# hdparm -Tt /dev/sda2

/dev/sda2:
Timing cached reads: 416 MB in 2.00 seconds = 207.64 MB/sec
Timing buffered disk reads: 86 MB in 3.02 seconds = 28.50 MB/sec
')

pogo P21 (V3) alarm USB Flash ext3
$this->bbcode_second_pass_code('', '
# hdparm -Tt /dev/sda1

/dev/sda1:
Timing cached reads: 466 MB in 2.00 seconds = 232.43 MB/sec
Timing buffered disk reads: 56 MB in 3.09 seconds = 18.12 MB/sec
')

Oh how I wish the V2's had SATA