Caporegime
- Joined
- 30 Jul 2013
- Posts
- 30,187
I spent a few hours last night tinkering with my i7 5930k to try and improve the overclock but what I realised was it wasn't quite as stable as I thought.
Firstly, my system specs:
Cpu: Intel i7 5930k
Motherboard: Asus X99-S (latest BIOS 1103)
RAM: GeIL EVO Potenza 16GB (4x4GB) DDR4 PC4-24000C16 3000MHz
GPU: Sapphire 295x2 & Sapphire 290x (Trifire)
Cooler: Swiftech Open Loop H240-x AIO (280mm rad / 2x 140mm fans)
PSU: SuperFlower 1200W Platinum PSU
First time I overclocked I used the 5 way optimisation (all cores) and it came back with a recommendation of 4.4Ghz at something like 1.29 volts (adaptive)
I then manually adjusted it in the BIOS AI Extreme tweaker and got what I thought was a stable 4.5Ghz at 1.31 volts. (Will come back to this later)
However, I noticed my RAM was 'only' operating at 2400Mhz, so I attempted to activate the XMP profile.
This changed the CPU strap and BCLK speed from 100 to 125Mhz and the multiplier from 46 to 36, and the memory speed to 3000Mhz which is supposedly what the RAM is rated to.
After this, the PC won't even POST.
Now I don't know for sure, but could this be due to an incompatibility between the BCLK speed and my GPU's?
The reason I ask is that I was in a situation where my BCLK speed was set at 102, either by AI Tweaker or the BIOS Tuning Wizard and although windows would load, the GPU's weren't detected properly, and re-installing the drivers would cause the screens to flicker on and off. The only way to resolve that was to set the BCLK back to 100.
Note that neither of my GPU's are overclocked past factory defaults...
If it isn't the reason for not getting past POST, then why is the CPU (seemingly) happy to boot in to Windows at [email protected] and play games, but the minute I change it to [email protected] v, it won't even post?
This brings me to another issue. I thought I had better properly test my system stability at 4.5Ghz so I downloaded the Asus 'Realbench' stress test, set it to 16GB and left it running for 15 minutes.
After 5 minutes it BSOD
So I upped core voltage to 1.32 and ran the test again
After 8 minutes another BSOD
I again upped the core voltage to 1.33 and ran the test again
After 11 minutes another BSOD.
So obviously my 4.5Ghz overclock isn't as stable as I initially thought. I was monitoring the CPU using Core Temp and during the last stress test most of the cores were in the 75°C range, but core 2 did hit 82°C. I believe this is still well within TJ Max temps but considering the hefty cooling I have on the CPU it was a bit of a concern.
For now I've dropped the overclock back down to 4.4Ghz as the 5 way optimisation initially set. But really I'd like to be able to run the Ram at 3000Mhz as well, or try and get my CPU stable at 4.5Ghz.
I got lucky on my 4770k chip as that did 4.5Ghz all day long at 1.2v core, and that was a simple overclock but the Haswell-E looks like it will need a lot more tinkering.
What other settings should I be changing?
Firstly, my system specs:
Cpu: Intel i7 5930k
Motherboard: Asus X99-S (latest BIOS 1103)
RAM: GeIL EVO Potenza 16GB (4x4GB) DDR4 PC4-24000C16 3000MHz
GPU: Sapphire 295x2 & Sapphire 290x (Trifire)
Cooler: Swiftech Open Loop H240-x AIO (280mm rad / 2x 140mm fans)
PSU: SuperFlower 1200W Platinum PSU
First time I overclocked I used the 5 way optimisation (all cores) and it came back with a recommendation of 4.4Ghz at something like 1.29 volts (adaptive)
I then manually adjusted it in the BIOS AI Extreme tweaker and got what I thought was a stable 4.5Ghz at 1.31 volts. (Will come back to this later)
However, I noticed my RAM was 'only' operating at 2400Mhz, so I attempted to activate the XMP profile.
This changed the CPU strap and BCLK speed from 100 to 125Mhz and the multiplier from 46 to 36, and the memory speed to 3000Mhz which is supposedly what the RAM is rated to.
After this, the PC won't even POST.
Now I don't know for sure, but could this be due to an incompatibility between the BCLK speed and my GPU's?
The reason I ask is that I was in a situation where my BCLK speed was set at 102, either by AI Tweaker or the BIOS Tuning Wizard and although windows would load, the GPU's weren't detected properly, and re-installing the drivers would cause the screens to flicker on and off. The only way to resolve that was to set the BCLK back to 100.
Note that neither of my GPU's are overclocked past factory defaults...
If it isn't the reason for not getting past POST, then why is the CPU (seemingly) happy to boot in to Windows at [email protected] and play games, but the minute I change it to [email protected] v, it won't even post?
This brings me to another issue. I thought I had better properly test my system stability at 4.5Ghz so I downloaded the Asus 'Realbench' stress test, set it to 16GB and left it running for 15 minutes.
After 5 minutes it BSOD
So I upped core voltage to 1.32 and ran the test again
After 8 minutes another BSOD
I again upped the core voltage to 1.33 and ran the test again
After 11 minutes another BSOD.
So obviously my 4.5Ghz overclock isn't as stable as I initially thought. I was monitoring the CPU using Core Temp and during the last stress test most of the cores were in the 75°C range, but core 2 did hit 82°C. I believe this is still well within TJ Max temps but considering the hefty cooling I have on the CPU it was a bit of a concern.
For now I've dropped the overclock back down to 4.4Ghz as the 5 way optimisation initially set. But really I'd like to be able to run the Ram at 3000Mhz as well, or try and get my CPU stable at 4.5Ghz.
I got lucky on my 4770k chip as that did 4.5Ghz all day long at 1.2v core, and that was a simple overclock but the Haswell-E looks like it will need a lot more tinkering.
What other settings should I be changing?
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