Topic Title: AMD A8-3870K - CPU speed fluctuation during stress test - HELP NEEDED!!!
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Created On: 05/07/2014 01:18 PM
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 05/07/2014 01:18 PM
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rajamsa
Peon

Posts: 2
Joined: 05/07/2014

Problem description:
During stress test (prime95) when CPU load is 100% CPU speed drops to minimum (multiplier: 30x -> 8x), when CPU temp reaches 57 °C (or core temp reaches 50 °C). When temperatures have dropped about 10 °C, CPU speed returns to maximum (multiplier: 30x) and the cycle continues.

Configuration:
Motherboard: ASRock A75M-HVS
BIOS: problem tested on versions: 2.00, 1.80 and 1.70
CPU: AMD A8-3870K (also tested on AMD A8-3850)
Memory: G.Skill F3-14900CL9D-8GBSR
2x4GB, DDR3, 1866MHz, 1.50V, 9-10-9-28-2N
Graphic Card: SAPPHIRE HD 6670 1GB GDDR5 Ultimate
OS: Windows 7 Ultimate 64-bit Retail
Temp monitoring: SpeedFan / AIDA64


BIOS / Advanced / CPU Configuration:
Core C6 Mode: Enabled
Cstate Pmin Mode: Disabled
Cool 'n' Quiet: Enabled
SVM: Enabled
CPU Thermal Throttle: Disabled

BIOS / H/W Monitor
CPU Fan 1 Setting: Automatic Mode
Target CPU Temp: 65 °C
Target Fan Speed: Level 1
Chassis Fan 1 Setting: Automatic Mode
Target CPU Temp: 65 °C
Target Fan Speed: Level 1


Also tested:

Core C6 Mode: Disabled
Cool 'n' Quiet: Disabled
SVM Disabled

CPU Fan 1 Setting: Full
Chassis Fan 1 Setting: Full

Is this malfunction due to faulty CPU?

Or is this malfunction because of BIOS?

Or is it Windows 7 related?

HELP NEEDED!!!

rajamsa
FINLAND

 05/30/2014 10:11 PM
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rajamsa
Peon

Posts: 2
Joined: 05/07/2014

Problem solved

As I originally suspected; the problem was in BIOS.
Although not in the way I suspected.
My original thought was that the BIOS code in itself was faulty,
as it turned out the code was OK, but the physical BIOS chip was faulty.

I discovered this by doing once again a BIOS update and ending up with a completely
dead PC. When I tried to boot it, the only thing that happened were beeping sounds from
the PC speaker.

I immediately contacted AsRock asking for an RMA for my motherboard.
AsRock tech people replied that the problem was probably a faulty BIOS chip and that
they would send one to me in the mail.

After receiving the new BIOS chip with the latest BIOS version, I removed the old one and
plugged in the new one.

Voilà, my PC was up and running and the original problem was gone.
No CPU speed fluctuation during stress test.

As I said in my thank you email to AsRock:
Excellent customer service.

rajamsa
FINLAND

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