[fuloyezih]

I have searched Google a lot, but could not find a solution.

I have installed the latest beta. Let's say I have three computers: C1, C2, and C3. C1 and C2 are connected using Ethernet, and C3 is using Wi-Fi. When copying a file C1->C2, I get about 100MB/s. When C1->C3, I get about 10MB/s (5GHz) or 5MB/s (2.4GHz).

C3 is of course capable of 300Mbps (Intel Dual Band Wireless-AC 8265). The linked speed is shown as 300Mbps. But after changing the stock firmware to DD-WRT, the Wi-Fi speed got that slow.

I have not changed much from the default settings. What's wrong?

Mode: AP
Network: N-Only 5Ghz
Width : HT40 (also tried Dynamic or Full)
Channel: Auto
SEcurity: WPA2 Personal (also tried disabled)
Alg: AES

I have seen the Status page, and there is some strange thing:

MAC Address Interface Uptime TX Rate RX Rate Info Signal Noise SNR Signal Quality
mobile 1 ath1 0:11:45 72M 6M HT20SGI -41 -96 55 100%
mobile 2 ath1 0:29:11 58M 6M LEGACY -52 -96 44 96%
My C3 computer ath1 0:29:20 135M 300M HT40SGI -59 -96 37 82%
mobile 3 ath1 0:29:44 300M 24M HT40SGI -43 -96 53

All other devices have higher TX but the C3 computer had higher RX rate (its TX rate was 135M).