On 2013-02-08 2:30 PM, Sujith Manoharan wrote: > Felix Fietkau wrote: >> In many tests throughput with ath9k_rate_control has been shown to be >> worse than with minstrel_ht (the mac8021 default RC). >> >> This module also has some other problems, like starting to use the >> highest possible rate early in the connection, causing problems with >> reliability of connection/authentication attempts. >> >> It also has a much more limited search space, ignoring many potentially >> useful rates, caused by the design decision to operate on a sorted rate >> set with the assumption that higher rates are always more unreliable >> than lower rates. In some scenarios this assumption is not true, and >> this can cause it to fall back to a really bad rate. >> >> minstrel_ht has been tested extensively in AP and client mode by lots of >> users (mostly in the OpenWrt project, where it has been the default for >> years). >> >> The only advantage that ath9k_rate_control previously had over minstrel_ht >> was the support for using CCK rates as fall back in case MCS rates got >> too bad, but this has now also been taken care of. > > Various rates are marked as invalid in the ath9k rate control module. I don't > know all the reasons, but the recommendation to disable certain rates came from > the internal algorithms team. How will this be handled ? I'm pretty sure it's because the algorithm isn't designed to handle more rates. It's a step-up/step-down type algorithm, and those typically only work with a sorted rateset, preferably duplicate free. Minstrel_ht selects rates in a different way that doesn't have the same limitations, so it can use the full rateset. - Felix -- To unsubscribe from this list: send the line "unsubscribe linux-wireless" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
