AT&T U-verse → Re: NV589 Bridge mode - Speed Degradation on ethernet port

Just as any FYI, the Asus RT-AC66U & the Asus RT-AC66R are the exact same router. The R is for retail sales (usually big box stores like Best Buy) and the U is if you order it from Asus or most online retailers.

Further to this, did you make sure the Asus and the Buffalo are not running the same chipset and/or a similar chipset from the same manufacturer? If they're both running the same or similar chipset from one of the big manufacturers, say Broadcom, it wouldn't be surprising to see the same issue show up since the chipsets are likely to act similarly if they are the same, from the same lineage (so the same code base), or the same company (which likely uses similar designs across chipsets)

Thanks Paralel. I was aware they were the same router, but hoped I had a problem with one of them so tried the other.

Great idea on the chipset. Going to explore that now. If they are both the same I will look for a router with a different chipset.

Edit: son of a... the buffalo is a Atheros and the Asus is a Broadcom. Are these two that similar?

Do you have "hardware acceleration" turn on. I remember hearing that any thing over 100M you need it turned on when using the Rt-N66U. it is in the Rt-N66U/R somewhere.

I did not. I had enable advanced (Per IP) logging turned on which killed the hardware acceleration. I have turned this off and rebooted and I am at 280Mbps. That may be because I just reset it up, but will monitor and see what happens. Will update when in a day or two or earlier if it drops.

Atheros and Broadcom are as different as you can get.

Also, the tip that Gap gave is right on regarding the Asus. Also, make sure QOS is off in the Asus. If you have that turned on, even though your router will indicate that Hardware Acceleration is on as well, if you have QOS turned on in the router, it will automatically disable the Hardware Acceleration since the two are mutually exclusive on the Asus Router.

If that still fails to resolve your problem there is one other thing that we can try, which is overclocking the processor and memory on the Asus.