All,

I've been lurking on the OpenWRT forum, looking to see when the CC builds for the WRT1900AC stabilized, and they seem to be so (for a very "beta"-ish version of stable).

So I went ahead and loaded up the daily ( CHAOS CALMER (Bleeding Edge, r45715)).

After getting Luci and sqm-scripts installed, I did a few baseline tests.  Wifi to the MacBook Pro is...  broken.  30Mbps vs. 90+ on the stock firmware.  iPhone is fine (80-90Mbps download speed from the internet).

After some rrul runs, this is what I ended up with:
http://www.dslreports.com/speedtest/538967

sqm-scripts are set for:
100Mbps download
10Mbps upload
fq_codel
ECN
no-squash
don't ignore

Here's a before run, with the stock firmware:
http://www.dslreports.com/speedtest/337392

So, unfortunately, it's still leaving 50Mbps on the table.

However, if I set the ingress limit higher (130Mbps), buffering is still controlled.  Not as well, though.  from +5ms to +10ms, with lots of jitter.  But it still looks great to the dslreports test:
http://www.dslreports.com/speedtest/538990

But the upside?  load is practically nil.  The WRT1900AC, with it's dual-core processor is more than enough to keep up with this (from a load point of view), but it seems like the bottleneck isn't the raw CPU power (cache?).

I'll get a writeup with graphs on the blog tomorrow (I hope).

-Aaron