For the last test, I ran a stress test that I've run on other routers, the WRT610N included, to see if wired and wireless bandwidth affect each other. The setup is the same as shown in Figure 9, but this time I ran only one stream each on the 2.4 and 5 GHz radios and added single LAN to WAN and WAN to LAN wired routing tests.
I first ran the tests with no bandwidth limits, i.e. blasting each stream as fast as it would go, which produced the results shown in Figure 11. The test starts the 2.4 GHz downlink stream first, then at 30 second intervals adds the 5 GHz wireless, wired LAN to WAN, then wired WAN to LAN streams. The wireless streams appear to share bandwidth fine, as you'd expect from the previous wireless maximum bandwidth test above.
Figure 11: Simultaneous 2.4 and 5 GHz plus routing - full bandwidth
But as soon as the first wired routing stream starts, wireless bandwidth on both radios is knocked down significantly. When the second routing stream is added, wireless throughput ends up being reduced by more than 50%.
Since it's unlikely that any router in a consumer setting would be connected to such a fast Internet connection, I re-ran the test, this time limiting the WAN > LAN speed to 50 Mbps and LAN > WAN to 5 Mbps, as you might have from a fiber-based ISP. Figure 12 shows what happened.
Figure 12: Simultaneous 2.4 and 5 GHz plus routing - routing bandwidth limits
When the 5 Mbps LAN to WAN traffic starts one minute into the test, both wireless streams seem unaffected. But when the 50 Mbps WAN to LAN traffic starts, both wireless streams get knocked down ~ 10 Mbps each.
So the lesson here is that the E3000 doesn't have unlimited bandwidth, which should be no surprise. But it appears that unless you have a very busy LAN and a very fast Internet connection, you won't run into the limits that I found.
For everyone who has been asking for a test of the WRT610N V2, well, you finally have it, since the E3000 is the same product with a new name. While the E3000 is a decent router and I'm sure that Cisco will sell plenty of 'em, it isn't as good as NETGEAR's WNDR3700, which is still the best-performing dual-band simultaneous N router that I've tested so far.