Question FX 6100 - what causes clock to go down?

[vissen]

OC is set to 3.60 GHz from 3.30 GHz base (though it hovers around 3.5 GHz - 3.46-3.57 - is it normal?). Clock regularly (every ~40s for ~15s) goes down to 1.37 GHz @ ~63°C. Is it throttling already at that temp or is it something else?
MB is Asus M5A78L-M LX3, all BIOS settings default except CPU multiplier.

 

[Darkbreeze]

FX CPUs can't be thermally monitored like other CPUs. Your numbers won't be accurate. Please read this and then figure out what your thermal margin is, but yes, the reality is that FX processors were likely to throttle at temperatures above 60°C.

How to Understand AMD CPU Temperatures | Daves Computer Tips

Over the years I've used both Intel and AMD processors and whichever monitoring utility I've used, it has always reported the real temperatures at core and socket. Since upgrading one of my PCs from…

davescomputertips.com

Also, you need to factor in the fact that you've got a very cheap board, barely capable of running FX 6 core processors at their stock configurations, much less while overclocking. Your throttling may not even BE from the CPU core temps, it may be from the poor VRM configuration on that board.

 

[vissen]

FX CPUs can't be thermally monitored like other CPUs. Your numbers won't be accurate. Please read this and then figure out what your thermal margin is, but yes, the reality is that FX processors were likely to throttle at temperatures above 60°C.

How to Understand AMD CPU Temperatures | Daves Computer Tips

Over the years I've used both Intel and AMD processors and whichever monitoring utility I've used, it has always reported the real temperatures at core and socket. Since upgrading one of my PCs from…

davescomputertips.com

Also, you need to factor in the fact that you've got a very cheap board, barely capable of running FX 6 core processors at their stock configurations, much less while overclocking. Your throttling may not even BE from the CPU core temps, it may be from the poor VRM configuration on that board.

Makes sense. So I guess I have to either run it on lower clock or try better cooling, yeah?

 

[Darkbreeze]

What does your full configuration consist of? Full hardware specs including case, number and size of case fans, location of case fans and orientation of case fans, as in, whether each of them are oriented to be intake or exhaust?

EXACT power supply model, memory kit model or specifications, etc.

 

[vissen]

What does your full configuration consist of? Full hardware specs including case, number and size of case fans, location of case fans and orientation of case fans, as in, whether each of them are oriented to be intake or exhaust?

EXACT power supply model, memory kit model or specifications, etc.

Woah, that's a lot. I wouldn't think many things affect the CPU that much.
Can't tell you anything about a case, it's completely random. Just one exhaust fan so I decided to keep the case opened. PSU is 500W, MODECOM premium 500, cheap local brand. Can't check RAM right now, all I can say is it's 2x4GB 1600 MHz (DDR3 ofc). GPU is a Palit 750 Ti if that's significant.

 

[Darkbreeze]

So, first thing is, you don't want to be overclocking with a generic cheap PSU like that. You're probably really lucky if works without any problems at the stock configuration much less with the additional stress of an overclock. Having a quality power supply is pretty much always a very important consideration for anything more than a very basic internet browsing machine, but it becomes incredibly important once you start overclocking anything including CPU, graphics card or memory.

The memory you have shouldn't be a problem for that platform since it's 1600mhz. Some of those FX platforms had problems with anything higher, like 1866mhz or 2133mhz, also some of them had problems trying to run four DIMMs because the memory controllers were rather weak on FX CPUs depending on the configuration.

What CPU cooler are you running? The stock cooler?

 

[vissen]

So, first thing is, you don't want to be overclocking with a generic cheap PSU like that. You're probably really lucky if works without any problems at the stock configuration much less with the additional stress of an overclock. Having a quality power supply is pretty much always a very important consideration for anything more than a very basic internet browsing machine, but it becomes incredibly important once you start overclocking anything including CPU, graphics card or memory.

The memory you have shouldn't be a problem for that platform since it's 1600mhz. Some of those FX platforms had problems with anything higher, like 1866mhz or 2133mhz, also some of them had problems trying to run four DIMMs because the memory controllers were rather weak on FX CPUs depending on the configuration.

What CPU cooler are you running? The stock cooler?

No idea if it's the stock cooler for a 6100 but it looks stock. No heat pipes, just a cube of fins and a fan with an AMD logo.

 

[Darkbreeze]

Yeah, that's the stock cooler then. My advice would be, stop. The stock coolers on the FX processors are not suitable for overclocking. If you want to overclock it is HIGHLY recommended that you AT LEAST get something like the 212 EVO or Gammaxx 400, at minimum. These are like 20-30 dollar coolers which can also be repurposed to a newer system if you upgrade at some point.

But the bottom line here is that unless this is being done just for fun/hobby it's probably a waste of time. You will never really see enough gains going from the stock configuration to 3.6Ghz to make it worth spending money on (Unless you have to get a new cooler anyhow OR plan to upgrade at some point and will be needing that cooler anyway) and given the age of the hardware already it's probably almost a certainty that overclocking on it is going to put it in an even earlier grave, especially since it's not a quality board to begin with. That board was never intended for, or good enough for, overclocking, even when it was new.

In fact, it even lacks heatsinks on the VRMs, which is generally a pretty good indicator that overclocking is a very bad idea on it.

 

[drea.drechsler]

I had both an FX4100 and anFX6300 (6 cores) CPU's so I can say pretty confidently that 3.6Ghz is a VERY mild overclock. Even on the stock cooler it should work OK enough, although I'd have it set to a pretty high speed (screaming) when doing so.

The more likely culprit is the VRM overheating. If your case has poor ventilation and there's no airflow back around the FET's, which have no heatsinks, they'll get toasty and throttle back the CPU. I had a similar Asus board that I tried running my 6300 on and it throttled incessantly until I put some glue-on heatsinks on the FET's and a fan blowing on them. But then I raised the overclock (to around 4.4-4.5Ghz) and it started again.

 

[DSzymborski]

I can see VRM overheating. This is a really low-end board. As Drea probably also knows since he's been around for a long time, we get a lot of people who aren't able to even get a 125W running at stock on that board. The good news is that this is one of the 95W CPUs, but there's just not that much performance to wring out of this platform. These Bulldozer CPUs were so underwhelming compared to Intel CPUs at the time and AMD's own previous Phenom II series that they completely killed off AM3+ after the Piledriver CPUs so that they could switch gears entirely in the hope that the Zen microarchitecture would save their bacon. And it did.

 

[Karadjgne]

FX temps are easy to understand, as long as you throw out Any preconceived notions of Temp as a definitive number. Actual physical max temp of the FX cores, as measured on specially modified by AMD engineering samples is 63°C. Those modifications didn't make it into the production cpus, leaving the FX without actual temp reading possibilities.

So AMD developed Overdrive as the result of need. And it's actually seriously good. The resultant number is not a temp. It's a value representing your closeness to max. It's comprised of a number of results from load, voltages, socket temps, amperage, and other things all put through an algorithm. That's the thermal margin number. If you see that number at 40, it's just a number, not a temp. Add a load, it might drop to 30, or 10 or 39, depending on the algorithm results. It simply means you have room for more heat output. If it gets below @ 10, the cpu is hot, if you hit Zero, it's at the thermal limit. So your range would be 40-0.

Looking through old posts, you'd often see ppl saying their cpu idles at 18° but at full load it's -20°. Basically that means their idle would be equivalent to an intel at 60ish°C and full load at 115°C. And they wonder why they have throttle issues.

For all intents and purposes, with FX, the word Temperature doesn't apply as a set specific number. You get a cold-hot range instead and the bigger the number, the further away from max you are.