need help overclocking my 3900X

[kaitlin4599]

im looking to overclock my 3900X on all 12 cores but have some questions



#1 is the aida64 full FPU stress test good for testing for a stable overclock on a 3900X? if its not what program do you recommend?

#2 whats the max safe vcore for 24/7 always on

#3 is there anything else i need to know havent overclocked a cpu since the LGA 1366 days

im on a 360mm aio and a CH7 hero mobo

also should i disable AVX in what ever program i use to stress test?


for context while PBO works ok for me i wanna try a static all core overclock

 

[dejo]

I wont claim to be an expert. Intel Burn Test is a decent stability tester that does so way quicker than prime95. That program does use avx instructions, and will generate a ton of heat. It should also bring more heat than any program that I could imagine using in daily tasks.
Many have said that 1.35v is the stop point for daily voltage.

 

[Tír na nÓg]

I agree, run a quick dirty test with IBT, and if it goes through, add a notch of vcore and run p95 for at least 6hours.

 

[Zerileous]

1.35 may be too much for Zen2 parts. Some seem to tolerate it but others have reported rapid degradation at those levels. 1.325v is likely safer (per the stilt).

A lot of people (mainly reddit) are recommending that you use your "FIT voltage" for these chips. This is derived from the CPUs internal silicone fitness monitor and is a little complicated. Using PBO (apparently just maxing them out is not ideal for ? reasons), buildzoid recommends PPT 300, TDC 230 and EDC 230, and then observing the maximum stable vcore in a program like HWiNFO64 while running a load like prime95 small FFT or AIDA should be fine as well. The reading to use is the one labeled SVI2 TFN, as supposedly this is the same number that the CPU reads in determining its boost. Of course after setting vcore manually it is necessary to repeat the load and see that the reading is the same, not the set vcore in BIOS and adjust your set voltage in BIOS or Ryzen master until you get the SVI2 TFN reading that matched. Of course this is all given that you don't encounter thermal limitations during the initial PBO run of prime95, which you can notice as a moderate decrease in voltage and clock speed (50 to 100 mV) around the 85c mark.

Since the 3900x is constructed with two dies with 6 cores each, it has been hypothesized that generally one higher quality die is used (such as would be used on the 3600x) and one lower quality die is used (such as would be used on the 3600). Hence the ryzen master features allowing different overclocks to be applied to different core dies has been reported as beneficial. On the down side, it's not a BIOS overclock but rather one that requires you to have a windows program running.

After all of this you'll likely find that stock, or stock with PBO enabled works out best for you since you're usually giving up hundreds of MHz in single core boost for at best 100MHz benefit in all core loads.

 

[DaveB]

Since the 3900x is constructed with two dies with 6 cores each, it has been hypothesized that generally one higher quality die is used (such as would be used on the 3600x) and one lower quality die is used (such as would be used on the 3600).

Exactly my 3900X experience. One die goes to 4.6 GHz on all 6 cores, the 6 cores on the other top out at around 4.4 GHz.

After all of this you'll likely find that stock, or stock with PBO enabled works out best for you since you're usually giving up hundreds of MHz in single core boost for at best 100MHz benefit in all core loads.

This has been my experience and so I always run my 3900X under PBO. On top of that, the CPU will run cooler and the fans will spin slower so the system is also quieter.

 

[Woomack]

Exactly my 3900X experience. One die goes to 4.6 GHz on all 6 cores, the 6 cores on the other top out at around 4.4 GHz.

My 3900X is more like one die - 4.6, the other one 4.4GHz ... all cores at once 4.35GHz and not an MHz more.
I'm thinking to maybe sell it before Ryzen 4000 will be released so the price won't drop so much. I just wish something like APU 4650G or 4750G, and I can't find it without a bundle with a motherboard.

1.35 may be too much for Zen2 parts. Some seem to tolerate it but others have reported rapid degradation at those levels. 1.325v is likely safer (per the stilt).

This is probably because this architecture is improved 1st Zen which was designed as low power and low voltage chip. It was scaling well and was really efficient up to about 3GHz but to make higher clock it needed a much higher voltage. 1.45V which is standard Ryzen voltage since release is already pushing it to the limits but at the same time the chip itself is stronger and has improved design so shouldn't degrade so quickly. On the other hand, there is a reason why 1.45V is only for a short time when the CPU runs at auto, and most of the time, it's closer to 1.2V.
I had no problems with my Ryzens but I've seen some users reporting degradation at ~1.5V.

 

[Metlcub]

I have my R9 3900X set at 4.35 ghrtz on all cores @ 1.2v and super stable with my AIO My Max temp was 62c after 45min under full load.. Not sure what type of OC you are trying to get , but you can get a good OC with also under volt. I am happy with 4.35 on all cores

 

[Zerileous]

That's not bad Metlcub!