HT/NB values set in BIOS don't take effect (990fxa-ud3 Rev. 4.0)

Hi all, first post here. Not quite a veteran overclocker but I've read and tinkered a good bit.

I have a 990FXA-UD3 rev 4 board with BIOS F3. I will update my signature after posting so you have my hardware info. I'm trying to get the most out of my fx8350 on air cooling. Right now it seems stable at 22.5 mp and 1.425 volts. Not impressive but I'm guessing my chip just isn't a great one. I tried 4.6 and temps got well into the 60C's and I wasn't stable so I stopped at 4.5ghz.

Then I tried to lower the MP and increase the BCLK to achieve roughly the same CPU frequency but get the advantage of faster memory/bus/HT/NB (i think that's all? maybe IMC if i understand correctly?)

Then I read that you want to try and keep the NB/HT at roughly the stock speeds and try to get just the memory tweaked out. Thing is, I can't change the HT/NB speeds. The defaults are 2200/2600 and I can manually type those values in rather than leaving it on auto, but they don't affect the system at all it seems. I boot to Win10 and run CPU-Z and it shows both are overclocked along with everything else. I don't understand why the settings don't do anything.

I'm also not sure if the HT/NB going up causes my instability but I guess that's a different question.

I turned off all the power saving settings, turbo, c1e, c6, apm, svm, cool&quiet ... I think I turned HPC back on after reading that it actually needs to be on to prevent the cpu from downclocking itself but I still see the CPU drop to 1400ish MHZ in HWMonitor on occasion. I don't know why.

I'll leave it that for now. Your comments are appreciated

You should be able to highlight the option (NB/HT) and use the (+) or (-) key to change the value then hit enter. Those busses have dividers so you can't just drop it 50 MHz you have to drop to the next divider. Can you not just raise the ram speed by one divider and adjust the voltage for it ? You didn't give many details on your ram. You would also be better served by getting the NB up to 2400 from 2200 anyway.

I turned off all the power saving settings, turbo, c1e, c6, apm, svm, cool&quiet ... I think I turned HPC back on after reading that it actually needs to be on to prevent the cpu from downclocking itself but I still see the CPU drop to 1400ish MHZ in HWMonitor on occasion. I don't know why.

Click to expand...

Did you set Windows power plan to performance?

Please, if your going to talk about Revisions on a MB, then say Rev 4.0, don't say r4 because that can confuse people to think there is a new GA-990FXA-UD3 (R5) is not a revision but part of the model name)
Sp to repeat, there is Rev 4.0 but NOT R4

I'll try those keys, I usually use page up/down. The BIOS doesn't have a divider/multiplier setting for those, just straight up MHz values. It lets me type a number and it saves the values, but it doesn't take effect according to CPU-Z.

Is the RAM multiplier linked to the NB/HT speeds? Or is there a separate hidden one? Is a divider the same as a multiplier?

RAM is G.SKILL Ripjaws Series 4x4GB 8x200 1.5V 9-9-9-24 with XMP profile.

I normally set my power plan to performance but I'll double check. Last night the lowest clock it had after gaming was in the 3GHz range (rather than 1400) and highest was 4.6 while it's supposed to be fixed 4.5 so I'm missing something.

I'll see if I can rename the thread title. I forgot there's an R5 model.

"Divider" is the proper term when referring to RAM Frequency steps. It is not normally linked to the HT/NB frequencies but all three of those are linked to the BLCK.

I played around with the NB/HT settings in the BIOS. It jumps in steps of 200MHz. If I type in a bad value it rounds it for me to the next step. If I type 2201 it jumps to 2200. If I type 2202 or higher it rounds it to 2400. So I couldn't put in a bad value. I set NB to 2400 and booted up. CPUZ still showing 2210ish. BCLK is at stock 200.

Power plan was set to high performance but I found the minimum processor state was at 5%. I changed it to 100% minmax and rebooted. I haven't monitored for long yet but it has stayed between 4491 and 4546MHz. I'll watch it some more and if it still fluctuates I'll post back.

Seeing a low of 3360 and high of 4611 so far. Still a big range for something that should be fixed afaik.

Is there a turbo mode that needs to be disabled in bios? Shooting in the dark here as I have not overclocked an FX CPU in a long time.

Yeah, it's disabled.

Even when running prime95 I see it go down on a pattern basis to 1400 or 1500ish. CPU utilization stays at 100% but the clock speed goes up and down. I hadn't noticed before if that's typical for prime95. 3 seconds at 1500, 3 seconds at 4500, 3 seconds at 1500, 3 seconds at 4500 etc.

Anyway, I upped the NB core voltage from default 1.625 to 1.2 and started increasing the bus speed. I'm at 225 and 8 minutes into prime95 so far. HT is at 2925 and NB freq at 2474 because of it. Still can't set them lower.

I've thought about going back to F2 BIOS as I read a post a couple of days ago that someone had an easier time getting overclocking stability on it. Why would it let me set a value if it doesn't do anything... sigh.

Side question, what's the highest NB core voltage I could safely try?

You're throttling. Is there an option in BIOS called APM ? If so disable it. Should be under CPU setting with the C-states and Cool& Quiet. Forget about NB abd HT for now. You need to get the OC working right first

Yes, APM was already disabled along with all the others. From memory that's turbo boost, cool and quiet, c1e, c6, svm, hpc, apm. I might be forgetting one. I set all the voltages manually to their defaults except for CPU which is at 1.425V to get 4.5ghz with just the multiplier. I set LLC to Medium. I even turned HPET off in the BIOS and Windows. Memory was all default with XMP. So now I'm lost.

I've since reverted the bclk overclock. It survived 20 minutes of prime but later on a game froze up likely due to that. I wanted stability for the evening so I reverted.

I'm wondering if I should reflash the BIOS or go back a version to see what happens. Not sure if there are issues with doing that. It's been a long time since I went back a version.

IIRC, the Giga boards were a bit backward, try enabling the APM and HPC

Okay tried it, and within a couple minutes of running I have seen it range from 4385 - 4549. It mostly sits at 4520-4521 but the dips and rises happen.

The dips to 1400ish don't happen every 3s now like before. I've seen it stay at 4.5 for 15 seconds and then do a quick dip while running prime. Seen it dip as low as 1397 though. Before it was always in the 1400-1500s range.

Any clue as to why the NB/HT values are ignored?

Not sure but I have seen weird thing with thos Giga AMD boards.

I think it's time you p[ost up a screenshot of p95 running ( 20 minutes) with HWMonitor or similar capturing the temps/voltages. You could be throttling due to socket/VRM temps.

Attached screenies. Took them while running prime. I have tried all 3 prime tests. I believe the small FFT's test is best for CPU testing so that's what I've used the most but the screenie happens to be of the Blend test. Temps are the same across all though.

The temps don't seem extreme but you're definitely at the end of that 212's cooling abilities. You can try placing a small fan on the VRM and behind the motherboard at the CPU socket. That should help with the throttling.

Just found this:

It seems that the HT multiplier max is 13 (2600) and the NB is 11 (2200). Setting the HT higher (ie. 2800 would = 14x) = no post. Setting the NB to whatever seems to always yield the same 2200 so fixed at 11. I brought the HT down to 11 so NB and HT are the same and then started upping the FSB while bringing down the RAM and CPU multiplier to keep them in check. I'm currently at 240 on the FSB, 4440 on the cpu, which means the HT and NB are now the same at 2640, RAM mp is 6.66 but with 240fsb it's back at 800. I was able to bring the temps down as well to the mid 50s as I was able to lower the CPU core voltage, while I had to increase the NB core. I seems the common safe voltage for NB core is about 1.35. Is the System temp in HWMonitor what I should watch for NB or is NB core/CPU_NB still CPU temp? I'll see how far I can push this and then try to find the sweet spot.

Any tips for finding a sweet spot? What benchmarks do you guys use? I've only been using cinebench.

The CPU_NB is part of the CPU so the heat from it is transferred to the core. It's nice to see you got something worked out. I find that CB15 is a good gauge for performance not so much for stability.