AMD high & unstable Idle temps
Posted by FreakMediaLP@reddit | buildapc | View on Reddit | 12 comments
AMD high & unstable idle temps
I am using a R7 9800X3D with a Lian Li Hydroshift II for a couple of months now. Gaming temps look great, at around 60-70°C, only surpassing 70°C during shader compilation. Despite that, my CPU sits between 53-60°C during Idle, spiking up on every occasion (like opening the browser) and even on its own every few seconds (look at the temp graph in the image).
Although these temps are nothing to worry about, it is really annoying to adjust a fan curve (which is supposed to only ramp up during gaming), if the margin between idle and gaming is that small. My fans either ramp up too late or during idle.
My AIO coolant sits at about 35°C in idle, I am running an undervolt at -10 all cores and even reapplied thermal paste today, without any improvment. If I increase the undervolt to -20, the gaming temps drop, but the idle temps do not, and they only drop below 50°C, if the coolant is still at room temperature (after boot or fans at full throttle).
Other users seem to have far better temps and I dont know what else to try at this point, so any help would be appreciated, maybe if someone could tell me, the clock speed ist ok.
Temp-Graph | Taskmanager | HWiNFO https://imgur.com/a/fpNE5Tv
PS: I know the CPU ussage seems a bit high from all the backgound tasks, but still with everythin closed, it stays the samme.
Mindless_Fisherman68@reddit
9800X3D idle temps in the 50s with brief jumps higher are normal AMD behavior, not a problem. a few things going on at once:
zen 5 boosts on a per-core basis the moment any thread asks for more than ~5% utilization. windows is constantly running background tasks (defender, search indexing, telemetry, browser tabs, RGB software). every one of those wakes a core from C-state, the core spikes to 5.0+ GHz at 1.4V for a few hundred ms, and the temp sensor reads that as a 70+ spike. you're seeing the boost algorithm working as designed, not a cooling problem.
the X3D chiplet has a metal lid bonded directly to the cache layer with a thinner IHS than non-X3D chips. that means the same wattage at the die translates to a higher reported temp, but the actual thermal density is fine. AMD calibrated the safety threshold for this, which is why the official Tjmax is 89C and the chip just throttles itself before doing damage.
the CCD-only sensor is what HWInfo and Ryzen Master report. the all-core average is much lower. don't watch "CPU" temp, watch "CCD" and check the package power (PPT). idle PPT under 30W, you're fine, period. PPT consistently above 50W with no foreground load means a background process is hammering, not a cooling issue.
if you actually want to flatten the idle behavior:
but none of this is required. 9800X3D running 50-70 idle on a 240/280 AIO is exactly what every reviewer reports. the chip is fine.
FreakMediaLP@reddit (OP)
Or did you really meant the "CCD1 Tdie" sensor, because this on has far lower temps, but seems to spike a bit more frequently
Mindless_Fisherman68@reddit
yeah, exactly that one. 9800X3D is single-CCD so CCD1 Tdie reads the raw silicon temp on that die without the offset Tctl applies. cooler readings, spikier because per-core sampling is faster than the smoothed package-level Tctl. for fan curves you want hysteresis. CPU Die avg (the 2-4C cooler one you mentioned) is the smoothest readout in HWiNFO, it averages across reporting points. either Tdie or Die avg works as fan source if you set 2-3C of fall-deadband in your fan software so the curve doesn't chase every bounce. boost still triggers on Tctl regardless of what your fan curve reads, so you're not affecting performance by picking a quieter sensor.
FreakMediaLP@reddit (OP)
Very much apreciated, thank you.
PPT is around 40W, with all background apps closed (from system tray) about 27W, so it is actually doing stuff.
You are right, the CPU Die (average) is about 2-4°C cooler on average, so I will use that as a source.
I will test the "Eco Mode" mode, the other two methods I am already using, also switched back to a -20 all core undervolt.
According_Spare7788@reddit
Interesting. Is this a 360mm AIO? For context, i have my 9800x3d under a Arctic LF III 360mm (not the newer pro version) and my gaming temps usually hover around 45-55c. And this is paired with a 5080 at 1440p ultrawide. Shader comp, where the cpu is hit with a heavy load can make it go up higher tho, 70-80c.
FreakMediaLP@reddit (OP)
Yes its a 360mm AIO, but the Arctic LF has a 1cm thicker radiator. But still 45-55 seems crazy, I dont even get those temps during Idle, what RPM are your pump and fans running at?
According_Spare7788@reddit
https://www.reddit.com/r/pcmasterrace/comments/1pkt6qn/i_am_shocked_by_the_9800x3d_temps/
Yeah, it's pretty amazing imo. And here's my old post about it with some pics. Compared to my old 5800x3d it's night and day.
I've only had delidded intel cpus under liquid metal that worked at this temp. Dunno if it because of the improve 3dvcache layer design or something. I don't remember about pump and rpm, i'll have to check when i get home.
Plenty-Industries@reddit
Set your AIO pump speed to be 70-80%.
Adjust the actual fan curve based on what you are okay with, balancing noise and temps. And then leave it alone.
"Idle" doesn't exactly mean "idle". Your CPU is constantly processing things in the background, whether you're doing something on the PC or not. Some of those processes, like Windows Defender, will start periodically - such a process requires additional CPU processing... so the load is increased and as a result the CPU gets warmer. Rinse and repeat.
Coolant temp is a meaningless metric because liquid has a far higher thermal capacity than what is able to be transferred from the CPU into the liquid due to thermal transfer inefficiencies.
This is all normal. Nothing to be concerned about. The CPU is designed to actually sit at its 95c thermal limit and adjust voltage and clocks to sit there, 24/7 for years on end. Anything below that is perfectly fine.
Don't obsess over things that are perfectly normal, and enjoy your PC.
FreakMediaLP@reddit (OP)
Alright, thank you very much for the clarification
FreakMediaLP@reddit (OP)
Can anyone tell me, if the clocks are right for idle and what these frequent temp spikes in the image graph are?
9okm@reddit
This all sounds normal. Your problem is with the fan curve hysteresis.
FreakMediaLP@reddit (OP)
I thought about that, but I don't like my coolant to go above 40+°C, although it should theoretically be fine until 50°C if im correct?
But if you say it is fine, I will give it a try