CentOS

I'm not overclocking, stability is most important for me since analyses sometimes take weeks.

I tried ram sticks in pairs and found two that worked fine (prime95 blend for a few hours and md5sum of larger files), and two that did not (failed both tests). I'm going to RMA the set giving me problems. I did not play around with voltages since the two good ones had no issues alone and the two bad ones did. If I have problems when going back to 4, I'll bump up the voltage.

Latest bios updates have resolved multiple issues with RAM, so update to newest possible.
As rysen support ECC , you might consider switch to ECC RAM /if yours doesn't have that feature/ and force the ecc kernel module.

I've solved this issue and thought I would post my experience in case anyone else has similar issues. The solution was to disable C6 State/Mode in the bios.

With this enabled, I get reliable hard freezes within hours unless I have a computationally intensive job running. With a job running, the system was stable for 60+days. Once I disabled that option, the system remains stable with no jobs running.

7.5 should be in CR sometime very soon and it would be interesting to know if the problem persists with the new 3.10.0-862 kernels.

jacscha wrote:I'm not overclocking, stability is most important for me since analyses sometimes take weeks.

I tried ram sticks in pairs and found two that worked fine (prime95 blend for a few hours and md5sum of larger files), and two that did not (failed both tests). I'm going to RMA the set giving me problems. I did not play around with voltages since the two good ones had no issues alone and the two bad ones did. If I have problems when going back to 4, I'll bump up the voltage.

For those of us of a "curious" nature

1) Who made your RAM and what was its rated MHz speed??

2) Is this more the maker of the mobo or model of mobo or is this a problem with ASUS mobo as well?? I'm looking at the ASUS X370-PRO mobo with a Ryzen 7 1800X CPU with 32 GB of GSkill TridentZ DDR4 2400 (PC4 19200).

3) As Ryzen is still a relatively "NEW" CPU. Have you checked to see if your particular mobo works well with Linux?!? There are some boards that a company makes that work will with Linux, and others not some much. I *try* to research which boards work well and which boards tend to have a finicky history running linux. The ASUS X370-PRO *seems* to work with Linux but there really is very little data out there so I have been more or less holding back. My current workstation has at least another 2-3 years left on it before I need to update it, but the next update will be to Ryzen, and I've actually speced out the above combo for a friend.

Your input will be valuable.

Thanks

The ram is Corsair Vengeance LPX (4x8GB) DDR4 DRAM 3000MHz C15

The motherboard is ASRock AB350 Pro.

I had one bad stick of ram, and issues with C State. Since those were resolved, the systems has been fine.

CentOS 7.5 is now in CR.