Setup - more
Figure 4 shows the view obtained from mousing over the dotted line connecting the two adapters. Mousing over individual adapters brings up a little menu where you can change the device name, turn the LEDs off, set the security code, futz with QoS settings, do a factory reset or get a "device list with column-type".
Figure 4: XAV5001 powerline utility
The last selection gets you a view like the one in Figure 5.
Figure 5: XAV5001 utility device-list view
QoS settings in powerline adapters are usually best left alone. But the XAV5001's settings are relatively understandable. Figure 6 shows that you can set four levels of relative priority (Highest, High, Normal, Low) for all traffic destined for a specific adapter and / or specific services by their TCP / UDP port number. Note also the options for 802.1Q VLAN or TOS header tags.
Figure 6: XAV5001 utility QoS settings
I used the same methodology as in the TRENDnet TPL-401E review so that I could append the results to the tables from that review. Ixia's IxChariot running the standard throughput.scr script generated TCP/IP traffic for testing. The only change made to IxChariot script defaults was to change from 100,000 Byte to 1,000,000 Byte test size. Each test ran for one minute.
Before testing I reset both adapters to factory default and ran the XAV5001 Firmware Upgrade Utility v18.104.22.168 I downloaded. It ran, but told me there wasn't firmware newer than the v0.2.0.9NA that came loaded into the adapters.
For yuks, I also ran the TRENDnet utility, which reported INT7400-MAC-5-0-5010-02-655-20101105-FINAL-D vs. the INT7400-MAC-5-0-5010-01-650-20100818-FINAL-B loaded on the TRENDnet adapters. So it appears that the XAV5001 has newer firmware than the TRENDnets had.
Because Atheros warned me that plugging both adapters into the same outlet or outlet strip could produce front-end overload and reduced performance, I ran "Location A" tests with both adapters plugged into the same wall outlet and also with one adapter moved to an outlet on an adjacent wall about 10 feet from the first.
Figure 7 shows a summary of download (receive) performance at the three test sites. Both Location A tests showed significantly higher throughput variation than the Location C and E tests, with the "different outlet" test indeed showing 82 Mbps, about 10 Mbps higher throughput than the "same outlet" test. So it appears that there is indeed a risk of overload and reduced performance from getting adapters too close together.
Figure 7: NETGEAR XAV5001 throughput, three locations, receive
But the really good news is the significantly lower throughput degradation as distance is increased between the NETGEAR adapters. Figure 8, taken from the TRENDnet review, shows both lower maximum throughput and over 50% throughput reduction in Locations C and E. In contrast, the NETGEAR adapters' lowest throughput is 68 Mbps, only a 17% reduction from best case.
Figure 8: TRENDnet TPL-401E throughput, three locations, receive
Table 1 pulls both results into one place for easier comparison.
(click link for throughput plot)