Originally Posted by Pedros
question ... is it normal the 3900x idles at 39-50ºC ?
Is there anything we can do to get these temps lower ( no manual overclock for now ) ?
Originally Posted by Oversemper
Just assembled 3800x+asus x570-f. EKWB custom water. Idles at the same temps, this is because auto voltage can hit 1.5v. So these 39-50C is internal transient temperature which can be lowed only by undervolting. Mine hits 4525 Mhz on 6 cores (not simultaneously, just statistic during the use), the remaining two "bad" cores hit 4450. These frequencies are the combination of good cooling with unrestricted autovoltage. Also I have PBO activated and set to +200Mhz mode. When I run intel burn test all cores are at 4.2 with 1.3 voltage, temp not exceeding 75C, everything automatically by mobo. So mobo pushes cores as high as its internal algorithms allow it, but it tends to apply massive overvoltage to eliminate instability and crashes. I'm kinda ok with it, coz anyway I'm going to swap 3800x for something like 4950x when (if) it arrives for AM4.
Suddenly I've managed to considerably lower idle temps when I was tinkering with ram overclock applying different dram calculator values in bios. It was like this. My 3800x on auto soc voltage successfully booted on Infinity Fabric 1866Mhz, ram is 3733Mhz. Infinity Fabric 1900Mhz unbootable for me whatever the soc voltage. Soc auto-voltage for IF 1866 & ram 3733 is 1.1v. I lowered it to 1.05 and it's stable in every torture test. CPU temps (idle and torture test) were not affected by the soc voltage at all.
Then I decided to apply VDDG CCD, VDDG IOD and VDDP voltages from the DRAM calculator. First I used the "Min." values from the calculator which are 0.950, 0950 and 0.700 ("700" in bios), respectively. It did not boot. The auto values for VDDG CCD, VDDG IOD and VDDP for me are unknown because they are not shown in the bios and I do not use ryzen master (the lesser there programs/services in windows the better). The "Rec." values from the calculator for me were 1.025, 1.025 and 0.900. But I tried 1.000, 1.000 and 0.900. It booted alright and I started HM monitor and did not believe my eyes. CPU temp now idles down to 33
! It almost never touched anything below 40 prior to that. Maximum temperature in intel burn test using 90% of ram did not change, it is 71-72 for me. Cinebench score also did not change. So, I guess, ASUS x570-f on bios 1405 (latest) sets too high VDDG CCD, VDDG IOD and VDDP, which keeps idle CPU temp elevated. It should be taken into account.