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FX-8350: Trying to understand why disabling cores improves game performance

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Maybe I'm missing it but I don't see what his brother is running the FX 8350 at. If its at default or only slightly OC'd, I agree with you the 970 mobo with 4 + 1 power phasing should handle it fine. But this is overclockers and if I was running an FX 8350 and trying to get optimal performance, I'd be shooting for an OC between 4.5 GHz and 5 GHz. For that kind of OC, I would want a 990FX mobo personally. And, while I'm not as knowledgeable as many others here on AMD, I'm not aware of any 970 mobo that has a true 8 + 2 power phase design.
 
if it was OC'd i would have mentioned that in the OP. The limitation of a 970 chipset board would likely not have many people OCing on one, especially OCing an 8-core.
 
Maybe I'm missing it but I don't see what his brother is running the FX 8350 at. If its at default or only slightly OC'd, I agree with you the 970 mobo with 4 + 1 power phasing should handle it fine. But this is overclockers and if I was running an FX 8350 and trying to get optimal performance, I'd be shooting for an OC between 4.5 GHz and 5 GHz. For that kind of OC, I would want a 990FX mobo personally. And, while I'm not as knowledgeable as many others here on AMD, I'm not aware of any 970 mobo that has a true 8 + 2 power phase design.

https://www.asus.com/us/Motherboards/970-PRO-GAMING-AURA/
http://www.gigabyte.com/products/product-page.aspx?pid=3907#ov

There are two I can think of off of the top of my head that handle the 8 cores and overclocking fine. They are both 7+1 or 8+1

if it was OC'd i would have mentioned that in the OP. The limitation of a 970 chipset board would likely not have many people OCing on one, especially OCing an 8-core.

There is no limitation using 970 vs 990. The chipsets more or less overclock the exact same. The quality of the board is where the difference is.
 
But not much over stock if any. Best is to undervolt as much as possible
 
https://www.asus.com/us/Motherboards/970-PRO-GAMING-AURA/
http://www.gigabyte.com/products/product-page.aspx?pid=3907#ov

There are two I can think of off of the top of my head that handle the 8 cores and overclocking fine. They are both 7+1 or 8+1



There is no limitation using 970 vs 990. The chipsets more or less overclock the exact same. The quality of the board is where the difference is.

Yes you are correct, board quality is an issue with 970 boards as they are slotted for lower-end builds. The 970 also has fewer PCI-e lanes, not affecting overclockability, but limiting high-end usage and therefore high-end build quality and pricing. Both boards you linked have smaller heatsinks on the VRMs, Northbridge and Southbridge than the better 990FX boards and there are no heatpipes so they are far more likely to overheat when overclocking.
 
Ok so here we go. Ran Prime95 smallFFT on it on saw a little fluctuation then after a bit there was a big fluctuation, a drop to 1.4ghz on all cores at 100% load pretty much. Guess its VRM throttling. I'll have him flip the rear fan to intake and possibly move the fan on the CPU heatsink to the back of it as well to double up intaking from the rear. The top fan is already exhaust so hopefully this should do the trick. As it stands, the VRM has hot air blowing over it i guess.

 
Disabling cool n' quiet mode and APM actually got it running at a slightly higher frequency, 4000mhz flat instead of 3991. Anyways, re-ran prime and witnessed the same thing happening with the throttling. In BF1, however, the issue has seemingly gone away. Ive still advised my brother to flip his rear fan to an intake and to otherwise optimize his airflow to blow over the VRMs better, so I guess there we go.
 
That IS NOT the answer. Like I said before add proper fans behind the mobo and on the VRM and dowclock/undervolt as much as possible. You brother is never going to have a satisfactory experience as long as it is throttling. Best answer is to get a decent board like the ASUS 970 Gaming Aura. For the $$ you can't beat it.
 
That IS NOT the answer. Like I said before add proper fans behind the mobo and on the VRM and dowclock/undervolt as much as possible. You brother is never going to have a satisfactory experience as long as it is throttling. Best answer is to get a decent board like the ASUS 970 Gaming Aura. For the $$ you can't beat it.

You are incorrect and not reading what im saying. Like i've said beore, Ive already advised for him to optimize the airflow around the VRM (which includes making the rear fan an intake which blows directly over the VRM in this case) and have advised putting a spot fan on there as well. The manufacturer support page for this board also states "additional cooling" for the VRM if using an 8350, which is supported and what is going to be followed. At this point in time the suggestion to buy a new board is a joke, especially since my brother was/is already on the verge of switching to intel. Being told to buy a new AMD board would just speed up the process of throwing out whats left of AMD in his build. Satisfactory experience? Again, as previously stated, satisfactory has been obtained and measures are going to be taken to ensure that "satisfactory" remains going forward.

So i guess there we go.
 
I assume that if everything was fine you wouldn't have asked for assistance. Reversing the rear exhaust doesn't work, it only disrupts the natural flow of air through the case. I tried it even made myself a nice louvered cover to further direct the air to the VRM that didn't work the best option is a fan on the rear of the motherboard. Like this, I used the fan off the stock CPU cooler or a small chipset fan will work. I have also put a 120mm slim 15mm thick fan in this position. This directly lowers the socket temps which are first to cause throttling.

Capturefan.PNG
vrm fans.jpg


This was my attempt with two 120 fans blowing in.
Capturevents.PNG
 
Very perceptive! There was an issue going on at first and I came here to help figure it out, and figured it out it was because you guys are the absolute best. It wasn't figured out before I posted, otherwise this thread wouldn't exist.

You are making too many assumptions. You don't know the air flow setup of the case, or what it can be after tweaks. Putting a fan on the VRM? This is like the third time I've repeated that it has since been advised. It'll be handled. Simply turning off cool n quiet and APM is not acceptable to me. It provided the short term solution for the games at the moment, but the other routes of cooling are still going to be done. The figuring out is done, the work is next.

So I guess there we go.
 
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Cool and quiet should still work with APM disabled. You'll need to keep APM that way. Pretty sure it only effects turbo boost. I just assumed that your case works the same way as every other case, cool air in the front/bottom warm air out the back /top. Good luck with your airflow.
 
Cool and quiet should still work with APM disabled. You'll need to keep APM that way. Pretty sure it only effects turbo boost. I just assumed that your case works the same way as every other case, cool air in the front/bottom warm air out the back /top. Good luck with your airflow.

Cooler Master HAF 932 is a beast for airflow. Though the future proposed changes to it will have it intaking from rear fan, heatsink fan flipped as well to further draw air in from the rear, top will is already exhaust but is a huge 220mm fan, huge 220mm side fan is on intake, front 120mm is on intake. With this setup, cooler air will enter the rear and pass over the VRM, through the heatsink, then up and out while cool air will be drawn in from the side and front. That big 220mm up top should be all the exhaust it needs. I think this will be more ideal given the situation. Then we can rectify the little things with spot fans and should be good to go going forward. Also, will become more positive pressure and deal with less dust. Currently, its an absolute dust monster. Cleaning it out every month or two isn't just good practice, its basically required.
 
That 200mm fan doesn't move crap. It's only 110 CFM.
You have 3 times the intake than exhaust, and coming from 3 different directions. Your airflow is a swirling heat sh1tstorm because there is so much going on that the heat doesn't have a chance to rise to your exhaust. It just keeps getting whipped around the case.
Smoother flow, is the WTG. ;)

Even if you added fans like Johan suggested, chances are it will still throttle, maybe just not as much. The board is sub standard for an 8 core FX.
 
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