Overclocking – 25% to 4.00 GHz

Raising the multiplier even further to 10x increases the processor’s clock speed from 3.60 GHz to 4.00 GHz. Here, the stock voltage of 1.250 V proved insufficient. Our QX9775 CPUs were only able to complete our torture test with Prime95 after we increased their core voltage to 1.400 V.

We do not recommend running the processors for extended periods of time with the voltage increased by 0.150 V. These CPUs were manufactured on a 45 nm production process and the risk of electron migration is simply too high. Nonetheless, the overclocking potential is a little higher than that of our socket 775 QX9770.

The next multiplier would be 11x, which force the CPU to run at 4.40 GHz due to the 400 MHz front-side bus. Our Skulltrail board refused to so much as POST at this setting. Obviously, the frequency jumps are far too big if we rely only on the CPU multiplier. So the only other way to increase the CPU’s clock speed any further is to underclock the FSB. We attempted to boot the system with the settings 11 x 386 MHz = 4.25 GHz. Sadly, even with more voltage tweaking, we were unable to convince our review CPU’s to boot at this speed.

2x Core 2 Extreme QX9775 @4.00 GHz

CPU Frequency	4.00 GHz (+25 %)
FSB	400 MHz (1600QDR)
Multiplier	x10
Core Voltage	1.400 V
Memory Multiplier	1.66x
Memory Frequency	FB-667 (333MHz DDR)
Timings	CL 4.0-4-4-12
Memory Mode	Quad-Channel

• 9 – Overclocking – 25% to 4.00 GHz
  

  1. 1 – Intel Skulltrail II - Core 2 Extreme QX9775
  2. 2 – Processors - Intel Core 2 Extreme QX9775
  3. 3 – Processor – The QX9775 in Detail
  4. 4 – Processor – Support for 43 Xeon Models
  5. 5 – Processor – Support for 43 Xeon Models (Cont’d)
  6. 6 – Processor – Support for 43 Xeon Models (Cont’d - 2)
  7. 7 – BIOS – No Memory Frequency Setting
  8. 8 – Overclocking – 12.5% to 3.60 GHz
  9. 9 – Overclocking – 25% to 4.00 GHz
  10. 10 – Skulltrail Board not Suitable for Overclocking
  11. 11 – More Core Voltage
  12. 12 – Idle Power Consumption higher than AMD 4x4
  13. 13 – Power Consumption – 227 Watts under Load
  14. 14 – System-Level Power Consumption – 470 Watts
  15. 15 – Energy Cost – €248 at 8 Hours a Day
  16. 16 – Other Parts of this Article
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