Quote Originally Posted by massman View Post
Any reason why the HT link has to be above 2G for better performance?

In regard to the efficiency: I suppose that Thuban still has the same issues as Deneb has when it comes to memory data transfer. AMD people confirmed that an elevated memory frequency is no use if you don't increase the IMC frequency accordingly. An appropriate ratio would be IMCRAM as 3:1, which would mean a 6GHz IMC if you want to make propper use of 2G memory.
It is an auto rule function in the BIOS, in fact raising HTT (Bclk) above 240 with both NB and HT set to auto will result in both of them falling back to 1920MHz (depends on ratios also), which is even worse, they should stay in sync at 2400MHz until the next auto rule limit is reached. So far, most Thuban processors we have tested will do NB/HTat 2600MHz on safe voltage settings so additional tuning is in order for the tables.

This will be corrected in the next BIOS but the main reason for maxing HT is to sync with NB speed (which you obviously want as high as possible on this platform) to keep the current memory table at optimum settings. Right now the rules are set to ensure stability/compatibility instead of maximum performance. Now that the AGESA code is stable for Thuban, we will set different rules when the BIOS "sees" performance settings being utilized.

Before anyone says anything, we went through four different AGESA code levels in the last two months or so as the platform and processors were finalized. This is the reason why we had around seven BIOS releases since the ES samples were delivered in early March.

Yes, to truly maximize memory performance, we truly need higher NB speeds to improve efficiencies as memory increases above 1066 on this platform. This is one of the main reasons I like to run NB/HT/Memory in high-sync where possible and why 1600C6 is still my favorite memory setting for everyday use, provided I have a IMC that allows that setting and 3200 on the NB/HT side. I have one right now that will do it on air so I am fortunate.