To probe further and make sure I wasn't seeing a special case, I also ran tests using 802.11b. Although I ran both throughput vs. throughput and throughput vs. streaming tests, I'll show just the dual-throughput tests since I consider them the worst-case conditions.

I first changed the Broadcom and GlobespanVirata products from 11g to 11b mode and left the Atheros-based equipment in dynamic Super-G mode. Figures 14 and 15 tell two very different stories.

Figure 14 shows that the Super-G WLAN tromps on the Broadcom WLAN, even when it's set to 11b mode. But Figure 15 shows that the GlobespanVirata-based equipment still interoperates very nicely with the Super-G WLAN, even when set to 802.11b mode. Note that for the tests shown, I started the Super-G WLAN first. I also ran the same tests starting the Super-G WLAN second and obtained similar results.

Figure 14: Throughput for Atheros Super-G vs Broadcom 11b - 10ft
(click on the image for a full-sized view)

Figure 15: Throughput for Atheros Super-G vs GlobespanVirata 11b - 10ft
(click on the image for a full-sized view)

For my last set of tests, I switched to pure 11b products. I chose a Buffalo Technology WLI-USB-L11G 11b USB adapter (which uses an ORiNOCO Gold PC card) and NETGEAR ME102 11b access point (based on a GlobespanVirata 11b PRISM chipset).

Figure 16 shows that when the 11b WLAN is started first, it continues undisturbed when the Super-G pair kicks in. Note that the Super-G pair is running at 12Mbps, typical for an 11g WLAN speed-limited by 802.11b protection.

Figure 17 shows that the Super-G pair starts out at around 30Mbps, but immediately drops down to 12Mbps to accomodate the 11b WLAN when it starts transmitting.

Figure 16: 10ft Throughput for Atheros Super-G vs 11b - 11b first
(click on the image for a full-sized view)

Figure 17: 10ft Throughput for Atheros Super-G vs 11b - Super-G first
(click on the image for a full-sized view)