Wireless Performance, Continued
Figure 5: Security mode performance comparison
Figure 6: Security mode performance comparison
When I switched over and ran the same tests with the Belkin card, the first run in Figure 5 shows the WEP128 and WPA-PSK / AES modes fared the worst with reductions in average throughput of 23% and 19% respectively, primarily caused by drops in throughput to under 16Mbps for at least half of each of the test runs. WPA-PSK / TKIP did a little better, turning in a 17% throughput hit, primarily due to a smoother throughput profile. The second Belkin card run, however, finally produced the behavior I'd expect, with significant throughput reduction (22%) only in the WPA-PSK / TKIP mode.
My conclusion? I suspect there's still some tuning left to do in the WLA2's code, which hopefully can make all clients - or at least all Broadcom-based clients - behave more like the Belkin card's second run.
- The WLA2's "Turbo" mode does not enable Broadcom's throughput enhancement Xpress technology, but just prevents clients that don't support the higher speed OFDM modes, i.e. 11b clients, from connecting.
802.11g Wireless Performance Test Results
|Test Conditions |
- WEP encryption: DISABLED
- Tx Rate: Automatic
- Power Save: Disabled
- Test Partner: Buffalo Tech WLI-CB-G54 CardBus client
|Firmware/Driver Versions AP f/w: |
Wireless client driver:
Wireless client f/w:
|Test Description||SNR (dB)||Transfer Rate (Mbps)||Response Time (msec)||UDP stream|
|Throughput (kbps)||Lost data (%)|
|Client to AP - Condition 1||58||20.8 |
|1 (avg) |
|Client to AP - Condition 2||26||16.9||1 (avg) |
|Client to AP - Condition 3||13||8.6||1 (avg) |
|Client to AP - Condition 4||16||6.8||1 (avg) |
See details of how we test.