I just recently changed my WR1043 v2 to a WDR4300 (both are TP-Link). 1043 has one USB port as I was capable to reach around 10-12 MB/s read speed on middle-grade USB3 flash driver with vsftpd.
4300 has a hub(GL850G) in place, but I couldn't read or write faster than 1.1 MB/s which is USB 1.1 speed. From the resources perspective top doesn't show any bottleneck, as I said the same drive with the same filesystem was 10 times faster. Both the routers are using 19.07 snapshot with the ath79 target.
root@OpenWrt:~# dmesg | grep -i 'usb\|hci' [ 0.152807] GPIO line 22 (tp-link:power:usb1) hogged as output/high [ 0.159814] GPIO line 21 (tp-link:power:usb2) hogged as output/high [ 0.393394] ar7200-usb-phy usb-phy: phy reset is missing [ 6.011611] usbcore: registered new interface driver usbfs [ 6.017322] usbcore: registered new interface driver hub [ 6.022803] usbcore: registered new device driver usb [ 6.056740] ehci_hcd: USB 2.0 'Enhanced' Host Controller (EHCI) Driver [ 6.083391] ehci-platform: EHCI generic platform driver [ 6.088995] ehci-platform 1b000000.usb: EHCI Host Controller [ 6.094827] ehci-platform 1b000000.usb: new USB bus registered, assigned bus number 1 [ 6.102874] ehci-platform 1b000000.usb: irq 3, io mem 0x1b000000 [ 6.134090] ehci-platform 1b000000.usb: USB 2.0 started, EHCI 1.00 [ 6.141299] hub 1-0:1.0: USB hub found [ 6.155395] usbcore: registered new interface driver usb-storage [ 6.894112] usb 1-1: new full-speed USB device number 2 using ehci-platform [ 7.136918] usb 1-1: not running at top speed; connect to a high speed hub [ 7.168798] hub 1-1:1.0: USB hub found [ 7.694800] usb 1-1.1: new full-speed USB device number 3 using ehci-platform [ 7.858914] usb 1-1.1: not running at top speed; connect to a high speed hub [ 7.888265] usb-storage 1-1.1:1.0: USB Mass Storage device detected [ 7.904681] scsi host0: usb-storage 1-1.1:1.0
Did anybody experience the same?