Server Black
Debian GNU/Linux 9.2 (stretch)
i5 processor, USB 3 port
16gb RAM
Server Silver
Debian GNU/Linux 9.2 (stretch)
i5 processor, USB 3 port
16gb RAM
The problem is Server Black has very inconsistent performance when accessing the USB drive but both report they are plugged into USB 3 ports.
Here are the results of a few of these:
Code: Select all
dd if=/dev/zero of=/data/testfile bs=1G count=1 oflag=direct
Server Black
1073741824 bytes (1.1 GB, 1.0 GiB) copied, 34.342 s, 31.3 MB/s
1073741824 bytes (1.1 GB, 1.0 GiB) copied, 38.5034 s, 27.9 MB/s
1073741824 bytes (1.1 GB, 1.0 GiB) copied, 54.9556 s, 19.5 MB/s
1073741824 bytes (1.1 GB, 1.0 GiB) copied, 38.9084 s, 27.6 MB/s
Server Silver
1073741824 bytes (1.1 GB, 1.0 GiB) copied, 12.3527 s, 86.9 MB/s
1073741824 bytes (1.1 GB, 1.0 GiB) copied, 11.7403 s, 91.5 MB/s
1073741824 bytes (1.1 GB, 1.0 GiB) copied, 11.247 s, 95.5 MB/s
1073741824 bytes (1.1 GB, 1.0 GiB) copied, 11.5433 s, 93.0 MB/s
I spent a couple days testing these things. My suspicion was Server Black was not really plugged into a USB 3 port.
Server Black
Bus 004 Device 002: ID 1058:25e2 Western Digital Technologies, Inc.
Bus 004 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
Server Silver
Bus 003 Device 002: ID 1058:25e2 Western Digital Technologies, Inc.
Bus 003 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
What could be causing the performance to vary between two pieces of hardware that are supposed to be the same?