Flemming Have done MANY tests with every combo of boards you can think of plus version of code with Linux. I can tell you the numbers below are right on with the tests you are doing. I am sure you can play with the settings on iperf to push these numbers a bit higher to around 28-29Mb but that's about it.
The issue is that the Atheros wireless driver relies heavily on the CPU where the Ethernet does not, this is one reason why the cards are lower cost to make these days. For example we tested and use a XScale 533Mhz core design and we maxed out at about 41Mb with a 54Mb link (all Atheros advanced options on using a pre-compressed 100Mb file) which is great using iperf, doing the same test via Ethernet was 95Mb. With this test CPU load never maxed out so we know we maxed the drivers performance. To answer your question we tested a Prism54 chipset card a while back and these used less CPU then Atheros, but because of costs I don't think you are going to see this going forward. For example cards from Ralink we are testing also put load on the CPU via the drivers. Anyone can easily do the same test with two X86 computer running a Linux build etc so the CPU is not the issues. Sincerely, Tony Morella Demarc Technology Group, A Wireless Solution Provider Office: 207-667-7583 Fax: 207-433-1008 http://www.demarctech.com -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Flemming Frandsen Sent: Thursday, May 31, 2007 12:47 PM To: [email protected] Subject: [Soekris] Atheros maxes out CPU at 24Mb/s on net4801 Hi, I'm using Atheros 5212 minipci cards with the latest linux driver (from SVN) and I find that I cannot get more than 24Mb/s out of the wireless link, is that normal? I've tested it by routing traffic through the link and running iperf on separate machines, so nothing runs on the net4801 machines other than the kernel and top. I first tried setting one box to AP and the other to Sta and that got me 13Mb/s with the CPU maxed out, when I switched to ahdemo mode (like adhoc, but without any fancy stuff like mac addresses) that got me 22Mb/s. Then I upgraded to the very latest driver and that got me 24Mb/s, but the CPU is still the bottleneck, which is really quite sad as I was hoping to saturate the wireless link. One could argue that I'm simply trying to go faster than the cpu allows, but I get 50Mb/s if I iperf to the box from eth0, so the CPU should be capable of routing that much, right? I guess my main questions are: * Is this really all I can hope for with Atheros cards? * If it's the card that has been designed to eat CPU then are there others that do more work in hardware? * On paper the net5501 looks to be about twice as fast as net4801, which is not quite enough to reach the performance I want, how does the net5501 CPU perform compared to net4801? Max at 54Mb/s (CPU maxed out): AP/STA mode: 13Mb/s ahdemo mode: 22Mb/s New driver: 24Mb/s 802.11a (ch 136): Bit Rate=54 Mb/s : 24.3Mb/s (0% idle) Bit Rate=36 Mb/s : 16Mb/s (15% idle) Bit Rate=24 Mb/s : 15Mb/s (37% idle) Bit Rate=6 Mb/s : 4.3Mb/s (81% idle) 802.11Ta (ch 152): Bit Rate=54 Mb/s : 23.5Mb/s Bit Rate=36 Mb/s : 23.5Mb/s Bit Rate=24 Mb/s : 23.9Mb/s Bit Rate=12 Mb/s : 17Mb/s Bit Rate=6 Mb/s : 9Mb/s The driver version is: ath_hal: 0.9.30.13 (AR5210, AR5211, AR5212, AR5416, RF5111, RF5112, RF2413, RF54 13, RF2133) wlan: 0.8.4.2 (svn r2377) ath_pci: 0.9.4.5 (svn r2377) ath_rate_sample: 1.2 (svn r2377) -- Regards Flemming Frandsen - YAPH - http://dion.swamp.dk _______________________________________________ Soekris-tech mailing list [email protected] http://lists.soekris.com/mailman/listinfo/soekris-tech _______________________________________________ Soekris-tech mailing list [email protected] http://lists.soekris.com/mailman/listinfo/soekris-tech
