Slow POST on Zen 2

Steo · March 3, 2020

I've been trying to figure this out for a while now, and the only thing I can find about it is that it's possibly from memory training. Basically, my X370 takes about 15-20 seconds on boot to POST (it takes this long before the internal speaker beeps). If I restart my computer, it posts within about 5 seconds, so it would be nice if it could do this from a cold boot. Does anyone have any advice on making it possibly POST faster?

I have already tried setting the RAM timings manually, so nothing there is set to auto. Also, when I look at the numbers on the motherboards display from a cold boot, it cycles through the same sequence twice before booting, displaying "19" before restarting the cycle. I also have the latest BIOS version, my specs are in my sig.

March 3, 2020

I have the same motherboard. From a cold boot there is nothing you can do to make the process any quicker.

That is the system going through the different checks to make sure everything is somewhat ok, when the system is already running, it has no reason to go back through this process and skips most of it.

I have the Crosshair VI Hero X370 and a Asus Strix B450, the Crosshair just has a much longer list of things it goes through before it reaches the Display.

nick name · March 3, 2020

What was said above. The more robust the motherboard the longer it takes to POST. The Crosshair VII does the same. My previous Prime X470 was far quicker to POST. My laptop is even quicker to POST.

Steo · March 3, 2020

I assumed so, Ryzen seems to just go through more checks than an Intel by the looks of things. I recall an earlier BIOS revision being slightly faster, where it didn't need to cycle through the tests twice. I could try it since I have flashback, but then it could cause other issues with the system, as it's probably happening for a reason.

I do think it's worth the longer post even if there's nothing that can be done, considering the price and performance of the chips.

Steo · March 11, 2020

I was messing around today since I recall my board definitely booting faster before, so I decided to try an older BIOS as a test (since I have flashback if something goes wrong anyway).

I rolled back to version 7501 and loaded my settings, the system was POSTing in 9 seconds. On versions 7601 and 7704, it takes about 18 seconds to POST, as it reboots during the RAM test for some reason.

It also turns out that clearing the CMOS on BIOS 7704 will make it POST in 11 seconds, but then as soon as you start changing anything like the RAM timings or CPU clock speed, it goes back to taking 18 seconds again. Loading optimised defaults will result in it still taking 18 seconds to POST, but pressing the clear CMOS button will make it be able to POST in 11 seconds again.

I'd almost stay on 7501 due to the fact that it halves the POST time and makes it boot much faster, but there are some changes in the later revisions, such as an AM4 combo PI patch. What I find weird about the newer BIOS revisions though, is that it will POST must faster until you start making changes. Using TPU to auto overclock the CPU will result in it still POSTing fast, but then as soon as you alter the ratio manually and save the settings, it goes back to having a slower POST again.

EDIT: It seems that the computer posts in 6 seconds if you had shut down from an OS on 7501, but unfortunately there were some issues from a cold boot (only if you had last shut down from an OS for some reason, powering off via the power button beforehand or just rebooting wouldn't introduce this issue) while using the D. O. C. P timings for the RAM. The second profile for my RAM worked (3000MHz with lower timings than 3200MHz), I'll have to look into it again tomorrow.