Thread: Intel Xeon PHI?
View Single Post
Old 2020-12-01, 21:33   #142
kriesel's Avatar
Mar 2017
US midwest

24×11×29 Posts

Originally Posted by ewmayer View Post
First performance-tweak I tried was fiddling with the onboard-memory frequency. The mobo User Manual uses a quite stupid scheme for indicating submenu levels, right arrows of slightly differing sizes rather than section/subsection numbering. So to get to the

Advanced Setup Configurations -> Chipset Configuration -> North Bridge -> Memory Configuration

Inside that rightmost submenu, I set the Enforce POR option to Disable (the only options were "Enforce POR" and "Disable"; the Enforce Stretch Goals" option cited in the manual was not listed.) Next I set Memory Frequency from its default "Auto" - nowhere did I see what actual clock setting that yielded - to the highest available, 2400, then rebooted. There is a related MemTest (Memory Test) option, for which we read "Select Enabled to enable memory testing during system boot. The options are *Enabled* and Disabled", so that is on by default and presumably we got at least a basic mem-test during boot. Fired up Mlucas to resume the 64-threaded F30 continuation run, waited for next checkpoint ... no change in timings. So it seems "Auto" was already setting the onboard-mem to the max displayed value of 2400.
Have you added DDR4 DIMMs to your system? These systems shipped from the seller with only the 16 GB MCDRAM in the processor package; 6 empty DDR4 slots. I'd expect changing Northbridge settings to have effect on any DDR4 present, and no effect on the much faster integral MCDRAM speed. If you mentioned adding DDR4, I missed it.

Last fiddled with by kriesel on 2020-12-01 at 21:49
kriesel is offline   Reply With Quote