"Dual-ing" Standards, continued
Of course, if you’re running more than one 11g card, you’d expect them to share the available bandwidth nicely. The Chariot plot in Figure 16 essentially confirms this.
Figure 16: Two pair test – Two Buffalo Tech WLI-CB-G54
(click on the image for a full-sized view)
This plot just happened to do the sharing during the downward throughput hop. It’s interesting to note that whatever the mechanism is that’s causing the hopping throughput, it didn’t cut the throughput yet again in half when the second draft-11g client kicked in.
I, of course, ran my usual four-location throughput test, the results of which are shown in the chart at the top of this section. I also did Chariot runs, which are shown in Figure 17.
Figure 17: Four condition throughput
(click on the image for a full-sized view)
The hopping throughput problem makes the plots not very useful, but I included the screenshot so that you can see the Max, Avg, and Min throughput numbers for each run.
I also ran tests with 128bit WEP enabled, and didn’t see any throughput degradation, at least none that I could separate out from the normally varying throughput.
Finally, I tried running some Turbo-mode tests, but couldn’t find a Turbo setting in the Buffalo Client application. After some back-and-forth, Buffalo told me that Turbo mode is presently implemented in the AP (router) side only. The client is supposed to auto-detect the Access Point’s mode, and adjust itself accordingly.
After following Buffalo’s instructions and setting the router into Turbo mode, I did a Chariot run and found that, once again, I couldn’t accurately see any Turbo effect due to the normal throughput variation. So the question of how much boost Turbo mode gives you, and whether it lowers effective throughput under weaker signal conditions as 802.11a’s Turbo does, will have to wait for a future firmware release.
802.11g Wireless Performance Test Results
| Test Conditions - WEP encryption: DISABLED | Firmware/Driver Versions AP f/w: | ||||
|---|---|---|---|---|---|
| Test Description | Signal Quality (%) | Transfer Rate (Mbps) | Response Time (msec) | UDP stream | |
| Throughput (kbps) | Lost data (%) | ||||
| Client to AP – Condition 1 | 100 | 15.5 [No WEP] 15.9 [w/ WEP] | 1 (avg) 1 (max) | 499 | 0 |
| Client to AP – Condition 2 | 75 | 16.5 | 1 (avg) 1 (max) | 499 | 0 |
| Client to AP – Condition 3 | 30 | 10.5 | 1 (avg) 1 (max) | 499 | 0 |
| Client to AP – Condition 4 | 45 | 6.9 | 1 (avg) 2 (max) | 497 | 0 |
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