860K OC Temp/Stability

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slyu9213

Honorable
Nov 30, 2012
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11,660
I'm starting to see the final endpoint in finding a stable overclock of my current computer so I am going to use the OP to make an overview of what happened.

My Build.

AMD Athlon X4 860K
Gigabyte FM2A88XM-D3H
Gigabyte Radeon HD 7850 1GB
8GB of DDR3 RAM (1333MHz-2400MHz)
Corsair H100i (4 fan, push/pull)
Cooler Master N200 Case
7X 120MM fans, 1X ~60/70mm fan

- I tried OCing initially by raising the BLCK and then again with just CPU Multipliers
- Highest OC to boot to OS = 4.7GHz, but never was stable even with 1.55v. All sorts of stress programs crashed quickly
- Highest OC to be stable is 4.5/4.6GHz
- Idle temps were 50C+ in the BIOS, Room Ambient Temperature is around 20C
- Corsair Link would not detect the H100i nor it's fans so the fans spun at a low RPM, I got this issue fixed later
- Stock paste of the H100i was used so I reinstalled the cooler (Remove, Clean, Repaste, Reinstall) and the temps dropped significantly almost 10C+. That shows I had bad contact between the cooler and CPU.
- The initial OC was done with RAM running at the stock 1333MHz speeds. I later overclocked the RAM to 1866MHz and 2133MHz. 2133MHz wasn't stable so I decided to use 1866MHz.
- Adding a small 70mm fan to spot cool the VRMs helped drop the temp times, with the addition of curing time for the Ceramique 2 Thermal compound that was used. The FM2A88XM-D3H has no heatsinks on the VRM so I installed my own.

- GSkill 2 x 4GB Ripjaws Z 2400MHz was bought for $64
- Computer would not work at the previously stable 4.5GHz OC at 2400MHz RAM speeds, so CPU was underclocked to 4.2GHz
- Prime95 tests still failed in Blend tests which stress a decent amount of RAM. So I did my overclocks again but this time used Small FFT so I could first find the stable overclock speeds without stressing RAM. Conclusion 4.5GHz with 1.464v.
- I ran Memtest86+ and got nearly 200+ errors very quickly. The 2400MHz RAM has default timings of 10-12-12-31. Seeing that AMD's 2400MHz RAM have CAS 11-12-12-31 I lowered the CAS 10 to 11. Running Memtest86+ for 5 passes and there are 0 errors. Very surprising one number makes that much of a difference in stability.

Stable OC Settings for my PC build.

4.1GHz (1.344v [+0.054])
4.2GHz (1.368v [+0.078])
4.3GHz (1.368v [+0.078])
4.4GHz (1.452v [+0.162])
4.5GHz (1.464v [+0.180])

I will be sticking with 4.5GHz with this build as it was the highest-stable OC through several tries. I will stick with 2400MHz for the RAM and stick with the 11-12-12-31 timings as they are stable in Memtest86 unlike 10-12-12-31 which causes a lot of errors. With those out of the way I am now going to look into overclocking my IMC/NB as that seems to boost memory performances a bit for the 860K. 1800MHz is the default speed 2000MHz should be pretty easy with little to no voltage increases to the NB.

.:edit:.

These voltages are no longer accurate. With F7 BIOS things have changed. +0.180 use to be 1.464v but now is 1.512v. +0,138 will be 1.464v now. Temps are now running higher than before. So far 4.6GHz is lasting longer i Prime95 but still failing at some point. Good news is I might be able to get 4.5GHz at a lower voltage. Lots of more stability testing to do now to find the newest highest stable clock.

.:edit:.

I have made a conclusion for myself that the best Temp reading for my 860K on my FM2A88XM-D3H motherboard is the CPU temps from the Super I/O Controller (ITE IT8620E) and the CPU 0 Temps are the closest for Core Temps. Both of these temps can be found on HWiNFO64. My reasonings is that the numbers from the Super I/O Controller seems to match well with the Thermal Margin given by AMD Overdrive. With my 860K overclocked to 4.7GHz with 1.548 (1.55V) I get average CPU Temps of low 50Cs to low 60Cs. Core Temps are 40-50C. Additionally when AIDA64 shows the same numbers from the Super I/O Controller. If the Maximum Operating Temperature for a 7850K is ~72.4C then a 860K (7850K minus IGP) should be about the same. If I am getting a Thermal Margin from 15-30C (15-30C of Thermal headroom) then that should match with the fact that the 50-60C as there is 10-20C of headroom until it hits ~72.4C. I could be wrong but I won't know until my CPU dies a premature death.
 
Solution
That's an awfully big OC on your RAM. Don't be surprised if one or more modules burns out in a much shorter period of time than should be expected for a memory module. I probably wouldn't take a 1333 module past 1866, if I bothered with it at all. The performance gains from overclocking RAM, or even from just using faster RAM, is minimal in most applications and operating systems. Lower CAS latency settings offer more improvement than the clock speed, and even then you probably wouldn't notice the different of a CAS 7 module versus a CAS 10 module except maybe in benchmarks. Very unlikely you would notice it in real world applications.

slyu9213

Honorable
Nov 30, 2012
1,054
0
11,660
Sorry for bringing up the topic again. Just wanted to update you or others on what has changed.

The 2400MHz RAM came in sometime this week and it has succesfully been installed/running at rated speeds with my motherboard and CPU. The 4.4-4.5Ghz OC I was running with 1866MHz RAM was not stable with the 2400MHz RAM so I dropped the CPU to 4.2GHz.

Initially the BIOS read ~45-50 C but after repasting/reseating the H100i it dropped to 35C at BIOS at stock speeds and voltage. The good news is that with a overclock to 4.2GHz with an ~1.36v VCore I am getting 31C in the BIOS. Additionally 4.5Ghz at ~1.422v VCore is running at only 39C. The only things that could have made an impact in the extra cooling is the additional 70mm fan I have no installed to spot cool the VRMs and that maybe the Ceramique 2 Thermal Compound has now cured to perform a little better.

.:edit:.

Okay so I tested for stability @4.5GHz at ~1.428V (+.138v) and the test failed almost immediately. After that I used (+.180) ~1.47v and it still failed. So instead I underclocked the RAM to 2133MHz instead of 2400MHz and the stability/stress test has not ended prematurely. Now I will try for 4.7GHz
 

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