Prime95 not maxing out my AMD cores

Calo

Calo

Calo

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Joined
11 Mar 2016
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361
Hi guys,

My A8 6600K black edition seems to be stable at 4.3Ghz but when doing the blend torture test with Prime95, only two cores are being pushed to 4.3Ghz while the other two sit at 1.9Ghz.

After one minute all cores run at 1.9Ghz. The temperature reaches 95 C for about 30 seconds before the clock drop.

Any advice on how to get them properly stress tested?
Im using HWMonitor to check the stats.

(core voltage is 1.4v)
(A8 is two cores, 4 threads)
 
Maybe they are maxing out but they are then underclocking themselves so they don't melt. Maybe you have a cooling issue.
 
lude1962 said:
The temperature reaches 95 C
oh dear your into chip frying..
what cooler are you using?
Click to expand...

Its a Zalman CNPS5X Performa
A big heatsink and I thought it would do a better job if im honest. Noisy too under full load. I did another test at a slower clock and it hit 91 C, same thing, the cores clocked down after a minute
 
Something's wrong if it's reaching that high, sounds like the CPU is throttling itself from going past the temp limit.

Are you sure the heatsink is making proper contact with the CPU? How did you apply the thermal paste?
 
Orcvader said:
Something's wrong if it's reaching that high, sounds like the CPU is throttling itself from going past the temp limit.

Are you sure the heatsink is making proper contact with the CPU? How did you apply the thermal paste?
Click to expand...

The pc was a new custom build delivered last year. It sounds like Im going to have to inspect the connection this heatsink is making as I didn't install it. That heatsink should give me adequate cooling right?
 
The fact that the temperatures rise almost immediately to throttle temperatures suggest that heatsink is not making a satisfactory contact with the CPU. Maybe there's an issue with the TIM.
 
Tealc said:
The fact that the temperatures rise almost immediately to throttle temperatures suggest that heatsink is not making a satisfactory contact with the CPU. Maybe there's an issue with the TIM.
Click to expand...

I've ordered some new TIM and will do clean up of the Zalman stuff. Is HWMonitor a reliable software to monitor cpu temp? It lists the processer temps under 'Package' but not indiviual core What software do you guys use to monitor CPU core temperatures?
 
Just wanted to close one of the loops here. Turns out that only AMD Overdrive software will give accurate Thermal Margin readings for each core for the APU series.
Good news is they dont go over 40 C when under full load.
Bad news is two of the cores still bomb out and drop the multiplier to x19 after a couple of minutes running ANY stress tests.

Very confused now. Whats causing this?
 
If the temps are within the thermal margins as reported by overdrive then the vrm's on the board are overheating which causes throttling.
Looking at the pictures of the board , only 1 component has a heatsink fitted.
Some boards are cheap for a reason.
 
lude1962 said:
Looking at the pictures of the board , only 1 component has a heatsink fitted.
Some boards are cheap for a reason.
Click to expand...

nuts. I cant try two things then. Lower the voltage im supplying and hope the 4.4Ghz stays stable. Or, maybe, retrofit a VRM Heatsink. Not even sure thats possible.
 
Update:
Great news fellas! once I dropped the voltage to 1.42 from 1.47 I now have four stable cores running stability checks, and an AMD Overdrive Benchmark score of 8563 (which is up from the 6664 i was getting when two cores were clocking down midway.)

So maybe that voltage was just a bit to much for my cheapo Mobo to handle. Im suprised as i didnt think the vrm would ever get close to a heat problem. I read thats only if clocking to 4.8Ghz+ with higher voltages

My shrewd setup is finally working out!
 
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