AMD Ryzen 5 2600 CPU temperatures spiking up and down in new build

[howtobeironic]

Today I have built a new PC with specs:
AMD Ryzen 5 2600 CPU (stock cooler Wraith Stealth, carefully seated and has spring screw system, but the preprinted thermal compund was too stuck that I had to rub the sink a few times with alcohol)
Kingston HyperX Predator 2x8 GB 3200 mHz RAM (somehow system calls it a 1200-1500)
Gigabyte Radeon 580 Gaming OC 8GB GPU
Gigabyte AX370M-Gaming 3 Motherboard
Cooler Master Masterbox 5 Lite RGB ATX case (3 intake, 1 exhaust fans of 120mm, exhause connected to motherboard and intakes are directly on PSU)
Cooler Master Masterwatt Lite 600W PSU
Arctic MX-4 Thermal Compound (applied with single dot method, quantity near a pea size or two lentils stacked)

It works, at least. Drivers are not there yet, and idle temps are fixed to 36 degrees celcius. Seems okay then.

Problem starts after putting it to a bit of stress. Testing with Roblox (not too demanding now, is it) and the usage on all cores is up to %80 instantly, and temps fire up to 70-75 degrees celcius on a 20-second timelapse and stays there until Roblox is closed, then after a second or two it falls back to 50, then starts decreasing steadily until it's back to 36. All this happens in a 1-2 minutes timeframe.

Testing with CPU-Z's Stress CPU feature(%100 on all cores), the exhaust cranks the RPM up, heat kicks up to 70 C max in 20 seconds (Expected temps but should it be this fast?) then when stopped falls back gradually until it's 36 again.GPU temps doesn't change much, steady on 31-35 degrees at the same time.

The question is, is this spike really normal and is it safe to continue usage(assuming that I won't be overclocking nor did any change to BIOS yet)? I'll probably reapply the compound and reseat the sink, but it sounds like a problem.

Thanks again.

 

[CountMike]

Spikes and fast ones are normal, there are multiple temp sensors (internal per core, part of XFR) but you are always shown one that has highest temp. One core, usually most loaded gets hot faster than other ones and presto, high temp.

 

[howtobeironic]

Spikes and fast ones are normal, there are multiple temp sensors (internal per core, part of XFR) but you are always shown one that has highest temp. One core, usually most loaded gets hot faster than other ones and presto, high temp.

Thanks for the reply, so I can assume that it's safe unless it hits 80-85? And also, CoreTemp shows the same temp on all cores.

 

[CountMike]

All programs show only one temperature (highest core) but internally Ryzen has one sensor per core used also internally by XFR to adjust frequency for best performance.
AMD says that although shutdown temperature is 95c. 72 - 75c should be your goal for longer periods. It gets even more complicated than that. There are two temperatures monitored internally and externally, one is higher by 10c, the one used by XFR (temperature offset). in 1st gen it was 20c, in second gen Ryzen it's 10c. Kinda like a safety valve.