Issues with AMD FX cpu thermal throttling

Doc Holliday

Doc Holliday

Doc Holliday

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This is the first time I've upgraded my own rig with the idea of tweaking it for greater performance. As budget is limited I went for AMD FX 6200, ASrock 990fx extreme 3 Mobo, 8 gigs of patriot 1600 ram to add into my CM storm scout case, hard drives and TX650 PSU. Now the kicker is I went for the CM siedon 120M AIO water cooler. In retrospect, this was the wrong choice but I was interested to see what I could do with it and added an extra fan for push pull config.

What I have found is even at stock 3.8Mhz the CPU is thermal throttling down at 52 degrees which it is hitting pretty quickly when I stress test on Prime95. So really, from what I can see, the cooler is not adequate.

Is there anything else I should be looking at?
 
A mix of core temp which I know is not the most accurate, HWMonitor, AXTU (ASrock mobo software) and CPU Z. I can see the CPU throtttling to 15Mhz everytime the temp hits around 52 on the AXTU readout for cpu temp. when it drops to around 45degrees it throttles back up to 3.8 and so on.

Just trying the tests again and getting throttling @ 53 / 54
 
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Your CPU cooler is fine, you are well in the safe temperature zone for now and replacing it wont help much.I would put my money on the VRM's being the ones to throttle you. I see 3/4 posts every week with that exact same board combined with a fx8xxx or a 6xxx. Let me link you to a similar thread started yesterday.

http://forums.overclockers.co.uk/showthread.php?t=18495319

Like you, this person recently upgraded to an FX chip, though 8 core and not 6 core, it still is a power muncher at load. Your board has only a power phasing of 4+1, this is not ideal for high power CPU's. Some board's are perfectly capable of powering these chips with 4+1 phasing, however i would say the quality of the extreme 3 VRM's aren't quite on the same level as it's competitors like gigabyte or Asus or even Asrock's own Fatal1ty.

How long stress testing before it throttles?

Is your VRM heatsink hot just after it throttles?
You don't need the exact temperature of the heatsink or VRM's (i don't think the board has a sensor there)

If it throttles pretty quickly (within a handful of minutes), it is very likely your VRM's, considering your CPU temperature is well within the safe zone. You could lower your CPU voltage and knock your multiplier down a tiny bit and see if you still get throttled.

If it is your VRM's, the best solution would be to return the board for another more suitable one, doesn't have to be more expensive. Gigabytes UD3 has 8+2 power phasing, better MOFSET's and will be able to clock your CPU well for about the same price. I have solved VRM throttling by directing airflow onto the heatsink or replacing it with a waterblock, however, if your throttled not long after you start your stress test, a bit more air wont save you and a watercooling solution for VRM's is overkill and more costly than a high end board which will perform better.
 
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Cheers, just tried that with big old 120mm aimed straight at the whole vrm/ cpu area. Sadly same results except took a little longer getting there but still only a few minutes. Oddly enough the CPU has throttled to 2.7 mhz this time and is staying there happily. However bios settings should be overidden with manual set up forcing a straight 3.8 all the time? bios issue maybe or cpu? or just failed cooling ?

AH thanks for the tip Avenged7. Yes the throtting doesn't take long to kick in and additional airflow via dodgey 120mm fan set up doesn't help either. I think it could be the Mobo as you say.

Any reccomendations on similarly priced mobo's ? I'm new to the amd stuff so reviews and recc's are all i have to go on.

Many thanks
 
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Doc Holliday said:
This is the first time I've upgraded my own rig with the idea of tweaking it for greater performance. As budget is limited I went for AMD FX 6200, ASrock 990fx extreme 3 Mobo, 8 gigs of patriot 1600 ram to add into my CM storm scout case, hard drives and TX650 PSU. Now the kicker is I went for the CM siedon 120M AIO water cooler. In retrospect, this was the wrong choice but I was interested to see what I could do with it and added an extra fan for push pull config.

What I have found is even at stock 3.8Mhz the CPU is thermal throttling down at 52 degrees which it is hitting pretty quickly when I stress test on Prime95. So really, from what I can see, the cooler is not adequate.

Is there anything else I should be looking at?
Click to expand...

You should have gone with a FX6300 and a cheaper motherboard. The FX6300 has a lower 95W TDP and consumes less power than a FX6200. Is there any chance you can return the CPU and the motherboard??
 
It sounds like the board just can't handle the power draw needed to run Prime95.

I'm not sure if Piledriver would be much better on a board like that (when pushing it with Prime95), personally I wouldn't recommend any 6-8 core AMD FX processor unless you are willing to invest in a decent motherboard for it like the Asus Sabertooth. Prime95 and AMD FX is a bit of a volatile mix.
 
mmj_uk said:
It sounds like the board just can't handle the power draw needed to run Prime95.

I'm not sure if Piledriver would be much better on a board like that (when pushing it with Prime95), personally I wouldn't recommend any 6-8 core AMD FX processor unless you are willing to invest in a decent motherboard for it like the Asus Sabertooth. Prime95 and AMD FX is a bit of a volatile mix.
Click to expand...

The OP is using a FX6200 which is a 125W TDP Bulldozer CPU. Piledriver based CPUs like the FX6300 have a lower 95W TDP and consume far less power. Moreover,as Legitreviews indicated their FX6300 overclocked more than a FX6200 consume 60W to 70W less at the wall.

My mate has no problems with a Gigabyte 970A UD3(8 phase VRM) which cost £75 and he has his FX6300 is overclocked to 4.3GHZ and his earlier revision version lacks LLC too. He used a 12 hour Prime95 run with no issue.

The same goes with the Asus 970 EVO(6 phase VRM). The VRM sections are the same as the 990X versions.

I also know people with the Biostar TA970 motherboard which costs £50 and this has no issues. Like all Biostar AMD motherboards they use 4 phase VRMs,but they are stronger than the ones found in AsRock motherboards for example. I would not overlock on it personally,but the people I knew who have them,were not overclocking so it was no issue anyway.

The 990X version uses a similar phase arrangement(stronger VRMs AFAIK) and both TPU and Anandtech had no issues with it.

It seems both MSI and ASRock AM3+ motherboards seem to be a tad hit and miss,it seems so I would not use them personally.

However,Gigabyte,Asus and other companies do make better AM3+ motherboards.

Just because a 125W TDP FX8350 probably needs a decent motherboard to be overclocked,does not mean the FX6300 and FX4300 series need £100+ motherboards.

There are plenty of decent 970 and cheaper 990X motherboards which will be fine.
 
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The ASUS M5A99X Evo at about £80-100 easily copes with my FX-8350 at 4.7+GHz, memory at 2GHz and bus clocks up to 302MHz. In fact throttling only occurs when the CPU temps hit 68C and above. This is with no active cooling to the VRM area. I believe it is a 6+2 phase power.

YOUR BASKET
1 x **B Grade** Asus M5A99X EVO AMD 990X (Socket AM3+) DDR3 PCI-Express ATX (MB-462-AS) £70.00
Total : £79.90 (includes shipping : £8.25).



B grade board, some accessories missing, may be driver disk, easily download utilities from ASUS website, or maybe cables.
 
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Download Asus Overdrive.

Fire it up, ENABLE turbo (as it should be disabled in bios, hopefully), then DISABLE turbo mode. APPLY or click OK.

Now fire up Prime, I bet it runs full belt!

My FX6300 had this daft restriction, doing the above unlocks whatever's stopping it from going full belt. Run CPU-Z at the same time, you'll see no throttling now :-)
 
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