Advanced Micro Devices Inc (AMD)

[dacaw]

E0 steppings, interesting post

This at Anandtech, comment posted by someone who sounds like they know:

"I don't think the BIOS of the test machine was adapted to Revision E Opterons.

I adapted LinuxBIOS to the Rev E stepping last week and the 1 GHz support is really the easiest thing (was already present in revision D processors). Changing the HT speed while the operating system is running is _very_ difficult. It requires a reset or LDTSTOP on both CPUs for the new frequency to be effective, so this is normally done a boot time in the BIOS. I guess ntune does not really change the HT frequency.

In addition Revision E has a number of errata fixed which result in improved performance (for example Errata 94).

The most important point is the new memory controller mode that reduces the DRAM bank conflicts. It improves STREAM benchmarks scores around 30%. This modes has to be automatically enabled by the BIOS, so please rerun the benchmark on a mainboard that supports Rev E processors."