So I just bought a Phanteks PH-TC14PE, trying to squeeze every last ounce of performance out of my FX-8350. My chip has never been a great overclocker, but this experience has left me a little bit frustrated. My absolute goal was to get 4.6GHz stable as a 24/7 overclock. I quickly realized this wasn't possible. These AMD chips can't take hardly any temperature before they start thermal throttling (around 66 C). Problem is, my chip needs gobs of voltage to overclock for whatever reason. I even have to bump the voltage up two notches just to get it to run stable at 4.2 GHz (it's turbo frequency). It has done this on two motherboards, by the way.
Needless to say, I have settled on a 4.5GHz overclock using a combination of FSB and multiplier. I have to crank the voltage to 1.45 to get this chip stable at 4.5GHz, and the temperature is still an issue. Under full load in Prime95, or when doing BOINC distributed computing tasks, it gets up to 65 C and stabilizes there, sometimes jumping up to 66 or 67 C for brief moments. This is with a $75 dollar 140mm dual tower heat sink. I don't really think the Phanteks is to blame here, but rather the fact that these AMD chips can't operate under very much heat at all, which is a bit silly seeing they are prone to get toasty (125w 8-core processor?)
I have a love-hate relationship with this CPU, but some days I do wish I just went Intel. The 62 C or under core temp is a bit hard to achieve when you make a processor that gobbles power and eats tons of voltage.
Probably just unluckly in the silicone lottery, I have a cheaper 8300 that can hit 4.5ghz at about 1.42V, and I didn't notice any throttling issues with what is basically a hyper 212, with a high pressure venturi fan on it
you might be able to hit it if you only use the multiplier for the CPU
What is your goal here? A few more FPS in certain gmaes, a faster render time or just bragging rights?
In reality if you are just a gamer over-clocking an FX 8350 from stock will not get you much more performance and might just lead to instability or a shorter life for your CPU.
When I had an FX 8320 I found that the best tactic was to aim for a base clock of around 4GHz and just create a higher turbo speed - I settled on 4.4GHz for my chip. In all my experiments getting 4.6 - 4.7GHz just was not worth it. I speant money on better cooling etc. for little net gain.
That particular machine now rocks an i5-4570, was the swap worth it, maybe, as it helped with performance in FSX, X-Plane and the ARMA series, but not as much as a subsequent video card upgrade made :-)
Silicon lottery ? Those temps are terrible for a average point of diminishing returns of most 8350's. ( 4.5 ) Temp issues can be caused by total package issues like case airflow, not using the correct fans ( static pressure verses airflow ect. ) and with the phanteks coolers being decent, i would look elsewhere first .Ambient temps. being to high ect.. My personal target temps for the 8350 under load is 55 c. You could of just lost the silicon lottery but i would carefully go back though the cooling system as a whole and consider everything carefully. Better thermal paste, different case, better fans, lowering ambients , remounting the cpu cooler ect......
I have the AC in my room cranked. Don't know what the ambient is right now, but its low. I have a Fractal Arc Midi R2, with a 120mm bottom intake, two 140mm front intakes, and two 140mm exhausts (top and rear). Used the thermal compound that came with the Phanteks coolers, which is supposedly good. Everything mounted down correctly, I work at a PC repair shop. I know how to mount a cooler. PSU is getting air from the bottom of the case so it's not exhausting any of it's heat into the case. My GTX 770 is doing nothing, so it's producing no heat. Right now I lowered it to 4.4Ghz, and lowered voltage a tad, it sits at 60 to 61 C at full load in P95 max heat stress test. Thinking this is where it is going to stay. Makes me wonder how the stock heatsink would have ever had a hope of cooling this chip had I ever used it.
the LLC is probably to blame for your high temps, and high voltage. recently help another member to get stable clocks on his 8350 and the LLC was the menacing culprit that went unnoticed for him.
Thats one of the settings I have hardly played around with. I have it set to medium, but my BIOS options are a bit confusing and I am not quite sure of the difference between the choices. There is Normal, Extreme, Medium, Low, and Auto I believe. Extreme causes crazy voltage spikes and I am afraid of it damaging my chip, medium has worked best for me so far, with low I get blue screens. Have not tried normal yet.
Definitely the core reason because I have gotten with stock voltage both FX-6100 and FX-8370 to run 4.4GHz and my brothers FX-6100 to 4.3GHz. I have Asus Sabertooth R2.0 and brother has the cheapest blue Asrock whatever board.
Voltage required for 4.8 runs way too hot on air, and 4.6 is still alrite +5c bump from that 4.4.
Basically FX overclock works so that you put all power savings and turbo off, then at least for me it didint seem to matter which ways I went for that 4.4 and both multiplier and fsb hit the same limit. I'm using multiplier only to get 4.6 because I dont really know what am I doing.
Seems alrite to me, like yours also jumps +5c just from the next voltage bump with 4.5, 4.6 probably throttles within moments in that Prime95. Don't know if it makes you feel any better, but you are just one multiplier behind the chip I have.
1.5v is way too dangerous as LLC can push it over the 1.55 threshold and instantly destroy the chip. The temps you are suggesting are way too much on Air cooling.
