Tweakers Australia has put 5 sticks of high quality DDR333 and DDR266 to the test in their latest article, DDR Memory Performance Roundup. The article explores the performance each stick has to offer in synchronous 133MHz and 166MHz as well as asynchronous 166MHz modes. Here"s a snip:
Not many systems out there run a system bus of 166MHz, so without an overclocked system your not going to benefit from the extra bandwidth DDR333 memory provides, since both AMD and Intel currently make CPUs that only run on a 133MHz bus. A lot of motherboards have a setting in the BIOS which allow you to set a divider that adjusts the DIMM frequency, enabling you to run DDR333 memory in on a system bus of 166MHz, 133MHz and even 100MHz. In my experience, running DDR333 in asynchronous mode doesn"t do much at all, as DDR memory can only derive its true speed and bandwidth from doubling the actual system bus in synchronous mode.