5800x undervolt seems off

[deen]

Late to the party, but I've just acquired a 5800x. Detail below, but in summary, this chip seems to hate vcore above 1.3v in temps, but undervolts under 1.3v well with a moderate overclock.

At Stock
This chip runs volcano hot at stock clocks and voltage. I see 58c idle with temps butting up to 90c in benches within a minute (and throttling). Vcore is what you'd expect at stock at ~1.1v on all cores and @1.45v on a single core when boosted. It's a veritable furnace in games after a few minutes.

Undervolting
This is where things get interesting... I tried PBO Curve Optimizing (can get to -25 stable everything else stock), but hardly any effect on temps. I then started lowering peak vcore (in Ryzen Master, then BIOS). With vcore at 1.18v, I can overclock to 4.2ghz on all cores stable with temps at 45c idle/67c load; At 1.2375v, I can get to 4400 with 51c idle/75c load; At 1.28, I can do 4.6ghz with 53c idle/79c load; Finally, at 1.3, I can get to 4.7ghz stable, but temps start climbing to the mid 80s load.

Anyone else seeing similar results? My impression -- from this single example, granted -- is this chip's stock vcore is far too aggressive.

I'm using my trust Alpenfohn Matterhorn with AC-4 paste (seated and re-seated to ensure good contact) -- not the beefiest of coolers, but should handle this CPU. Case is a Corsair Obisidan 650D with great flow. Cooling shouldn't be the issue. I do have an Adata XPG Levante 240 AIO on its way, but not expecting miracles.

That's interesting. You just manually ajusted the vcore? Did you also run the vcurve offset with the lower vcore or only lowered vcore?

But you mention your idle loads go up to 53c at 4.6ghz so that means you run a steady OC 24/7? I'm not sure if 53c idle 24/7 is a good thing. My idle is around 29c and bumps up to 75c at full load with an average clock around 4.55 - 4.6.

 

[harmattan]

That's interesting. You just manually ajusted the vcore? Did you also run the vcurve offset with the lower vcore or only lowered vcore?

But you mention your idle loads go up to 53c at 4.6ghz so that means you run a steady OC 24/7? I'm not sure if 53c idle 24/7 is a good thing. My idle is around 29c and bumps up to 75c at full load with an average clock around 4.55 - 4.6.

What vcore are you running for a stable 4.6ghz?

Yes, I just manually lowered my peak vcore and voilà, significantly lower temps with a decent OC (and confirmed performance increase in benches). I just revisited monitoring my temps at 1.28v/4.6ghz and it's actually idling around 48c once calmed down after benches. Still a bit hot at idle, but not concerning IMO. I suspect my new AIO should help here with idle temps (it's my first AIO apart from closed-loop GPUs e.g. 295x2. I've always built my own custom loops but wanted something lower-maintenance).

 

[deen]

What vcore are you running for a stable 4.6ghz?

Yes, I just manually lowered my peak vcore and voilà, significantly lower temps with a decent OC (and confirmed performance increase in benches). I just revisited monitoring my temps at 1.28v/4.6ghz and it's actually idling around 48c once calmed down after benches. Still a bit hot at idle, but not concerning IMO. I suspect my new AIO should help here with idle temps (it's my first AIO apart from closed-loop GPUs e.g. 295x2. I've always built my own custom loops but wanted something lower-maintenance).

I'm not sure but around 1.325V at full load and very low below 0.9 at idle. Was hoping that I could bring it down with PBO resulting in lower temps and higher clocks but that's not really helping in that regard. Just like your own findings.

At 100% full load on all cores i'm round 78c. So temps are really fine and should be much lower with lower vcore resulting in higher clocks.

I'ts not concerning but 50c all the time sounds like a bit hot though. I would not want to run that hot when just browsing for example. When comparing my cinebech and 3d mark results i'm holding up pretty good only a few points below hard OCéd CPU's so ill just stick with this since the performance gains (for gaming) are not that big anyway.

I've recently started to invest some in OCing RAM because this has a much bigger impact on the 5800x. Should be aiming for 3800mhz running 1:1:1 seems to be the sweetspot performance wise.

 

[harmattan]

Hmmm.... While I'm able to hit 4.6ghz at 1.28v stable, but anything above 1.3v is stable but causes inferno temps. Wonder if there's a correlation as to why I can get good clocks/performance (and reasonable temps) at low vcore, but temps suck at stock?

My RAM can't really go past 3400 with looser timings. I'm more concerned with getting a handle on my CPU voltage-clocks-temp dynamics at present.

 

[deen]

Well, every cpu is different but i've read a lot about 5800x owners seeing 90c's all the time. You could try lowering EDC/PDC settings. This helped for many but In my case it only degraded my performance while not seeing lower temps.

 

[harmattan]

I've pulled it back to 1.28 @ 4.5ghz for the time being until I get the AIO installed which will hopefully get temps under control. Any higher voltage, and temps get uncomfortable after 20 minutes of load. Current cooling setup just can't disperse the heat (and there's a hella lot of heat coming off it). As it is, this chip is completely unmanageable at stock, I don't even think a peltier cooled with liquid N would help.

I haven't experienced a chip this hot-running since prescott.

 

[deen]

I've pulled it back to 1.28 @ 4.5ghz for the time being until I get the AIO installed which will hopefully get temps under control. Any higher voltage, and temps get uncomfortable after 20 minutes of load. Current cooling setup just can't disperse the heat (and there's a hella lot of heat coming off it). As it is, this chip is completely unmanageable at stock, I don't even think a peltier cooled with liquid N would help.

I haven't experienced a chip this hot-running since prescott.

I was wondering, if you have a static OC to 4.5 GHz, how does that work in single core performance? I Assume your single core is also @ 4.5GHZ or does it boost up to atleast 4850?

 

[harmattan]

No, all cores locked at 4.5 GHz. I'm a bit of a luddite with Ryzen overclocking, so am not sure if you can overclock and maintain a single-core boost.

I installed my XGP Levante AIO this morning and temps are much better (44c idle/72c load @ 4.5Ghz 1.28v) but still reach 90c after a minute or two at stock voltage and clocks in Cinebench. I can, however, overclock to 4.7Ghz @ 1.31v stable and load temps stay around 80c. I think my original bad temp results were a combo of a hot chip sample and light-weight cooler (Alpenfohn Brocken really not meant to cool this chip). I'll never be comfortable running this chip at stock voltage, but am happy with my current undervolt/overclock.