Will adding mos-c1 heatsinks cool vrm's better then stock

[crosslhs82]

Hi
Hoping somebody can help.
I think I have a problem with the vrm's throttling during P95 testing on my fx 8350 on my Gigabyte ga 970 gaming sli ocing anything over 4.3g on stock voltage.
This system is w/cooled with the corsair h100i with the fans replaced using the noctua 120mm 3000 rpm fans set at top as exhaust.
Cpu temps 37c during tests.

Also using the fx wraith cpu fan mounted directly over the vrm mosfet heatsink about an inch away.

The questions;

Is this common with the gigabyte ga-970 gaming sli and the fx 8350 or is this a possible rma ?

Will removing the stock heatsink and replacing with the Enzotech mos-c1 lower the vrm temps enough for a little bit more oc ?

Or is there any other solutions?

I'm not trying to get an extreme oc, but would be happy with anything over 4.3g

System specs:
Win 10 CU
Fx 8350
Ga-970 gaming sli
Corsair h100i with 2 120mm noctua fans top as exhaust
Zotac gtx 960
Crucial 525gb ssd os
Pny cs1311 120gb ssd programs
Toshiba 1tb hdd storage
Corsair cs750m psu
Elgoto hd60pro capture card

Thermaltake f31 suppressor with 120mm fan at bottom and front bottom as intakes
140mm front middle or top position intake, and 140mm rear as exhaust
And the stock 8350 wraith fan mounted about 1 inch away vrm heatsink using a L bracket from Home Depot attached to the rear 140mm fan corner.
Thank You for your time and knowledge in advance.

 

[bigpinkdragon286]

Removing the stock heat sink and replacing it with a better heat sink may help, but in the case of the Enzotech heat sinks you plan to use, it actually looks like you'll be ending up with smaller heat sink capacity overall.

If the monolithic heat sink is not making ideal contact with all of the chips beneath it, this may factor in to the current problem you're identifying. Replacing with individual sinks at that point would certainly help then.

On the other hand, depending on how Gigabyte has affixed the sink to the chips beneath, you could be risking damage during removal. Some thermal solutions can be as bad as glue, ripping traces and solder in the process of removing them.

That you have a fan actively cooling the current heat sink is probably as good as you can hope to get temperatures in that area in any reasonable fashion, unless of course the heat is simply pooling there and has no place to go.

Even after getting ideal cooling for your VRM MOSFETs, you may find they still throttle. It may be a matter of current limiting that is throttling your power delivery, not heat, and there's not going to be anything practical you can do about that.

Edit:

Looking at the CPU support list for your motherboard you will see that the 220 watt FX CPUs have not been validated, the first of which runs at 4.4 GHz. Either Gigabyte never bothered to test the CPUs with that board, or the board has issues past a certain level of current draw. The FX CPUs scale really poorly in terms of power usage, so my first guess is you may actually be up against a current limit here on that board with your existing overclock, unless you have some good temperature numbers to say the chips are just too hot still.

 

[crosslhs82]

Thank You for a Excellent response.
The enzotech was for an example. I would prefer only if I have to, use a gigabyte heatsink if there were no others that would work but still at a very last resort.

I think I will try to get with gigabyte tech support and see what they think.

Using hwinfo64 at 4.3g on a 7 1/2 hr P95 blend test my cpu passed but showed a 21.4 multiplier average.
Over 4.3 that average dropped while I was watching.
It would change the multi from where it was to 7 back to where I had it and back and forth still passing P95 blend tests.

I don't know for sure like you say if it is heat to blame, and thinking of getting a heat gun to measure.

So with those multi's dropping is there any way to verify whether the cpu is being throttled?

 

[bigpinkdragon286]

I've only ever witnessed my 8370 throttle when it's thermal margin was within 1 - 2°C of 0 (approximately 72°C), but throttle it did, consistently and successfully. Brought the temps down about 5°C or so, and then it stopped throttling, heated up again, and the cycle continued until I stopped pushing the CPU. This of course, was on a motherboard that is rated to handle the 220 watt FX CPUs. I didn't keep the CPU overclocked long term however. I personally didn't find the temperatures worth it. The compromise I found reasonable was to keep the normal 4.0 GHz stock clock, but bump the boost clock to 4.6 GHz.

You might find that a high boost clock will work where an all-core overclock doesn't, and it might run stable with far less core voltage, remaining within the TDP limits of your motherboard VRM section.

If your multiplier is bouncing from where you set it to 7, the lowest multiplier possible, under full load, yes, your CPU is throttling. Whether it's throttling because your CPU is too hot, or because the VRM section of your motherboard is too hot or running too much current would need further investigation.

The simple answer may end up being that you need a motherboard with a better VRM section. For the small improvements you're going to see in a 100 MHz overclock, this would be a terrible value.

 

[crosslhs82]

Thank You again for responding.
The throttling I have is mild @the 4.3g over the 7.5 hrs tested the multi average was 21.4 of 21.5 that's still pretty sad that the board can't handle even that mild of an oc.
I do remember seeing a cpb and what looked to be a multiplier setting. I will try playing around a bit and see what happens while trying gigabyte tech support as the board was bought less then 3 months ago.
I'm not really going to expect a lot out of them but they can still listen my discontent with issue of not being able to run even a mild oc.