[SOLVED] AMD FX 8370 Overclock - A potential throttling issue

[foxhound525]

So I've been experimenting with a multiplier overclock on my CPU, the idea was to squeeze some extra performance out for VR until next gen hits and an upgrade is necessary.

I managed to disable all the bios stuff that was blocking me (like powernow etc), enabled custom p states and HPC, put it at 4.5Ghz and got it fairly stable. The big issue is that when under load, it performs as expected most of the time, but it also regularly drops down to 1.4Ghz for a second or 2 before jumping back up. After testing until 3am last night, I found this was the cause of the significant regular performance dips I've been having in VR, and that my performance is actually better on stock settings without these weird CPU spikes. The overclocked performance is significantly better when it doesn't throttle however, so there is a gain to be made if I can stop the core speed dropping.

What I'm trying to figure out is what the hell is going on. My PSU is overkill, and I have a Gamaxx 400 cooler, so I have a suspicion that maybe its VRM throttling (as the CPU never exceeds 57 degrees C and even then it normally maxes out at 52, well below max operating temps). How I can actually verify that I have no idea though. I've only overclocked one CPU before and didn't run into this, can anyone help?

EVGA Supernova 850W Semi Modular 80+ Bronze Power Supply
AMD FX 8370 Black Edition 4GHz Socket AM3+ 8MB L3 Cache + Gammaxx 400
Asus GTX 1060 TURBO 6GB GDDR5 Graphics Card
Biostar TA970 Plus Ver. 5.x Socket AM3+ 8-Channel motherboard
3 HDDs
2 SSDs

 

[sizzling]

That motherboard looks to have a 4+1 VRM design which is a weak setup. It at least has a heatspreader which puts it ahead slightly of some other boards but it’s really not a good choice for overclocking a 125w cpu. I very much suspect the VRM’s are the problem.

 

[foxhound525]

That motherboard looks to have a 4+1 VRM design which is a weak setup. It at least has a heatspreader which puts it ahead slightly of some other boards but it’s really not a good choice for overclocking a 125w cpu. I very much suspect the VRM’s are the problem.

Thank you for confirming my suspicions. Can I ask how you knew that or where you found that info? I tried scouring the website for my mobo and I don't think it even mentions VRMs.

And would you say that I shouldn't overclock at all, or that I should just be conservative with it? I'm considering trying for 4.2Ghz (100mhz above boost) just to see if it can handle anything above stock and then incrementally upping it from there (probably should have done it this way the first time)

 

[sizzling]

Thank you for confirming my suspicions. Can I ask how you knew that or where you found that info? I tried scouring the website for my mobo and I don't think it even mentions VRMs.

And would you say that I shouldn't overclock at all, or that I should just be conservative with it? I'm considering trying for 4.2Ghz (100mhz above boost) just to see if it can handle anything above stock and then incrementally upping it from there (probably should have done it this way the first time)

I found a review that said it had 5 phases which I expect they mean 4+1. How much you push it depends how much of an issue will it be if the motherboard fails. While there is protection built from the posts online I’ve seen many people come for help when their low end motherboards fails over the years.

 

[foxhound525]

I found a review that said it had 5 phases which I expect they mean 4+1. How much you push it depends how much of an issue will it be if the motherboard fails. While there is protection built from the posts online I’ve seen many people come for help when their low end motherboards fails over the years.

Ah well it was a cheap mobo, if it fails I can use that as an excuse to get one with better VRMs. I plan on doing a new build with ryzen in the next year or 2 so I'll need an am4 board anyway.

I've done some testing this morning and 4.3ghz seems stable under stress with no throttling and no additional voltage required. 4.4 and above requires additional voltage which seems to increase the chances of random throttling, so I'll leave it at 4.3 for now and call it a win!

One final question, what number of vrm phases/what vrm setup would you look for in a overclocking mobo? For a serious performance overclock but not crazy Ln2 level stuff. Just with solid air cooling

 

[sizzling]

I recall 8+2 being what the higher end FM3+ motherboard used but try to find one that hasn’t been stressed to the max overclocking or running a FX9XXX cpu might be a challenge.

 

[foxhound525]

I recall 8+2 being what the higher end FM3+ motherboard used but try to find one that hasn’t been stressed to the max overclocking or running a FX9XXX cpu might be a challenge.

Oh wow, can you literally not buy new AM3+ boards anymore? I saw someone recommend a Gigabyte GA-970A-UD3P ATX AM3+ for its 8+2 phase delivery but I can't seem to find stock for that anywhere.

I guess I will have to look at refurbished motherboards (never thought I'd say that) when/if this one dies.

Thanks for your help!

 

[sizzling]

Oh wow, can you literally not buy new AM3+ boards anymore? I saw someone recommend a Gigabyte GA-970A-UD3P ATX AM3+ for its 8+2 phase delivery but I can't seem to find stock for that anywhere.

I guess I will have to look at refurbished motherboards (never thought I'd say that) when/if this one dies.

Thanks for your help!

AM3+ was discontinued years ago and has been out of production for about the time AM4 was released.

 

[drivinfast247]

It's a dead platform. Time to upgrade everything.