Writing to USB 3 drive slow


#1

Hi I have a B1300 with version 2 software (I use MESH so version is not yet an option). When I try to write to the USB3 drive attached to the router I get speeds of 5-7MBps. When I try to write to another computer on the network it is twice as high. When I use the drive attached to the router, but I attached it to my machine the speeds are normal USB3 rates. Why is the B1300 so slow at writing to the disk?


#2

5-7Mbps is normal for the router. It is USB3 specs but the SoC cannot handle fast speed.


#3

I just did a small test with a usb 3 drive copying ~20Gbytes of data over windows share/samba, and I get:

Read: 44MB (mbytes)
write: 32MB

I think the huge performance penalty you have is maybe because of the filesystem you use on your drive. I have my desk formatted as ext4… and I’m running vanilla openwrt. The SoC is not that slow when using native protocols (at least not 5-7MBps territory).


#4

I shrank the ntfs partition, created an ext4 partition, copied the data between the partitions and removed the ntfs partition.
Now I don’t see anything from the drive through SAMBA and the mount point is “mnt/Basic data partition”.

What is going on? The NTFS mount point was “mnt/Elements”


#5

Finally managed to get the ext4 partition visible. No real difference on the speed of transfer.instead of 7-8 MBs I am getting 7-9MBs.

Any other ideas?


#6

I should mention that it is a 4TB disk.


#7

Not sure as far as what’s going on with the ext4 setup, but I can tell you from experience - opensource ntfs-3g (as opposed to Tuxera’s proprietary variant) is far more CPU intensive than most filesystem drivers. ext4 should perform significantly better especially if you’re CPU-bottlenecked.

Edit: What protocol are you using? NFSv2 and some NFSv3 configurations do not permit server write caching which utterly kills write performance, especially for smaller writes. Is there a possibility the ext4 partition is mounted with the “sync” option?


#8

Everything is default settings. I have not altered any of the B1300 defaults. So I don’t know what to tell you concerning the protocols used o9r the mounting options.


#9

Reading your original post again, it seems you are using the gl.inet firmware.

As I mentioned in my reply, I’m using vanilla openwrt. While the gl.inet firmware is basically the QSDK, which itself is based on openwrt, the changes from that to current openwrt are substantial (4.4 vs 4.14 kernel, DTS-based, different USB drivers/ext4…etc). Could be any of those…

I didn’t expect that much of a performance discrepancy, maybe its a minor thing… but it could be anything.