Overclock.net › Forums › Intel › Intel CPUs › i7 875k to 3.8GHz
New Posts  All Forums:Forum Nav:

i7 875k to 3.8GHz

post #1 of 27
Thread Starter 
I picked up an i7 875k yesterday at Micro Center for $199.

I'm trying to get it stable at 3.8GHz, but I'm having a terrible time.

Right now, it failed Prime95 blend after 20 minutes with:
bclk - 181 x 21
vCore - 1.35 LLC off
vtt - 1.21
PLL - 1.9
PCH - 1.12

I've tried 152 x 25 and 159 x 24 and none of these are stable.

Shouldn't I be able to do this quite easily with 1.35 vCore? I've also attempted 1.29 vtt, but no luck there either.
Cloaked
(13 items)
 
  
CPUMotherboardGraphicsRAM
i7 875k @ 4.0GHz Gigabyte GA-P55-UD3L Sapphire HD 4870 1GB Toxic 2 x 2GB OCZ Gold 
Hard DriveOSMonitorPower
C300 128GB + Caviar Black 1TB Windows 7 Pro 64-Bit Samsung 23" 1080p 550W Antec Truepower 
CaseMouse
X-Clear Acrylic Case G500 
  hide details  
Reply
Cloaked
(13 items)
 
  
CPUMotherboardGraphicsRAM
i7 875k @ 4.0GHz Gigabyte GA-P55-UD3L Sapphire HD 4870 1GB Toxic 2 x 2GB OCZ Gold 
Hard DriveOSMonitorPower
C300 128GB + Caviar Black 1TB Windows 7 Pro 64-Bit Samsung 23" 1080p 550W Antec Truepower 
CaseMouse
X-Clear Acrylic Case G500 
  hide details  
Reply
post #2 of 27
Why stay at 860 multiplier when you have a 875k?
Try to up the multiplier and turn LLC on with 1.35v
Main Rig V 6.8
(16 items)
 
  
CPUMotherboardGraphicsRAM
Intel Core i7 6850K @ 4.4Ghz Asus Rog Rampage V Extreme U3.1 GTX 1080 Ti @ 2050/6000 Corsair Vengance LPX 16GB DDR4-2800 
Hard DriveHard DriveHard DriveHard Drive
Intel 600P 512GB NVMe Samsung 850 PRO 256GB Samsung 850 EVO 500GB WD Caviar Black 640GB X2 
CoolingOSMonitorKeyboard
Corsair H115i AIO Windows 10 Pro x64 Philips BDM4350UC 4K Monitor 10bit + LG IPS231P Corsair K70 LUX CherryMX Brown 
PowerCaseMouseAudio
Corsair AX1200 80Plus Gold Thermaltake Core P3 Logitech G502 Proteus Core  ALC1150 Optical Out to Pioneer VSX-824-K 
  hide details  
Reply
Main Rig V 6.8
(16 items)
 
  
CPUMotherboardGraphicsRAM
Intel Core i7 6850K @ 4.4Ghz Asus Rog Rampage V Extreme U3.1 GTX 1080 Ti @ 2050/6000 Corsair Vengance LPX 16GB DDR4-2800 
Hard DriveHard DriveHard DriveHard Drive
Intel 600P 512GB NVMe Samsung 850 PRO 256GB Samsung 850 EVO 500GB WD Caviar Black 640GB X2 
CoolingOSMonitorKeyboard
Corsair H115i AIO Windows 10 Pro x64 Philips BDM4350UC 4K Monitor 10bit + LG IPS231P Corsair K70 LUX CherryMX Brown 
PowerCaseMouseAudio
Corsair AX1200 80Plus Gold Thermaltake Core P3 Logitech G502 Proteus Core  ALC1150 Optical Out to Pioneer VSX-824-K 
  hide details  
Reply
post #3 of 27
Its been said before not all chips are made equal. Some chips will OC like a MOFO, others like dogs.
post #4 of 27
Thread Starter 
Just tried 152 bclk x 25 again at 1.35 vcore, failed after 5 minutes.
Cloaked
(13 items)
 
  
CPUMotherboardGraphicsRAM
i7 875k @ 4.0GHz Gigabyte GA-P55-UD3L Sapphire HD 4870 1GB Toxic 2 x 2GB OCZ Gold 
Hard DriveOSMonitorPower
C300 128GB + Caviar Black 1TB Windows 7 Pro 64-Bit Samsung 23" 1080p 550W Antec Truepower 
CaseMouse
X-Clear Acrylic Case G500 
  hide details  
Reply
Cloaked
(13 items)
 
  
CPUMotherboardGraphicsRAM
i7 875k @ 4.0GHz Gigabyte GA-P55-UD3L Sapphire HD 4870 1GB Toxic 2 x 2GB OCZ Gold 
Hard DriveOSMonitorPower
C300 128GB + Caviar Black 1TB Windows 7 Pro 64-Bit Samsung 23" 1080p 550W Antec Truepower 
CaseMouse
X-Clear Acrylic Case G500 
  hide details  
Reply
post #5 of 27
You try 147 x 26 yet? Whats your RAM running at?
    
CPUMotherboardGraphicsRAM
Core i3 550 @ 4,202,210,000hz 1.32v K0 MSI P55-GD80 PNY GTX 465 (not unlocked yet) Super Talent Speed 1750mhz @ 7-6-6-24 
Hard DriveOSMonitorPower
320GB Seagate SATA II 7200 RPM + 200gb Barracuda Windows 7 64 bit pro Viewsonic VG700 17"/Westinghouse 42" LCD Rosewill Bronze 1000w 80 plus bronze 
Case
Blue Custom Techbench :) 
  hide details  
Reply
    
CPUMotherboardGraphicsRAM
Core i3 550 @ 4,202,210,000hz 1.32v K0 MSI P55-GD80 PNY GTX 465 (not unlocked yet) Super Talent Speed 1750mhz @ 7-6-6-24 
Hard DriveOSMonitorPower
320GB Seagate SATA II 7200 RPM + 200gb Barracuda Windows 7 64 bit pro Viewsonic VG700 17"/Westinghouse 42" LCD Rosewill Bronze 1000w 80 plus bronze 
Case
Blue Custom Techbench :) 
  hide details  
Reply
post #6 of 27
Try turning that PLL down to 1.8v. More then likely don't need it raised that high, and could be throwing your OC outta whack.
Black Dynamite
(13 items)
 
  
CPUMotherboardGraphicsRAM
Core i7 875K ~ 4.027Ghz(22x183)@1.388v HT on EVGA P55 SLI E655 EVGA GTX 480 SC - [903c/2100m] G.Skill PC17600-(2200Mhz)-CL7-4GB Pi's 
Hard DriveOptical DriveOSMonitor
64GB Corsair C300 (OS)-300GB Vraptor-1TB WD Black Samsung Super Writemaster DVD-R/RW Windows 7 Home Prem. 64 bit 40" Toshiba 1080p HD 
KeyboardPowerCaseMouse
Logitech G15 Corsair TX850W Silverstone TJ09-B Logitech G9x 
Mouse Pad
Rocketfish game pad 
  hide details  
Reply
Black Dynamite
(13 items)
 
  
CPUMotherboardGraphicsRAM
Core i7 875K ~ 4.027Ghz(22x183)@1.388v HT on EVGA P55 SLI E655 EVGA GTX 480 SC - [903c/2100m] G.Skill PC17600-(2200Mhz)-CL7-4GB Pi's 
Hard DriveOptical DriveOSMonitor
64GB Corsair C300 (OS)-300GB Vraptor-1TB WD Black Samsung Super Writemaster DVD-R/RW Windows 7 Home Prem. 64 bit 40" Toshiba 1080p HD 
KeyboardPowerCaseMouse
Logitech G15 Corsair TX850W Silverstone TJ09-B Logitech G9x 
Mouse Pad
Rocketfish game pad 
  hide details  
Reply
post #7 of 27
Thread Starter 
Ram is bclk x 8 right now. Stock timings and voltage.
Cloaked
(13 items)
 
  
CPUMotherboardGraphicsRAM
i7 875k @ 4.0GHz Gigabyte GA-P55-UD3L Sapphire HD 4870 1GB Toxic 2 x 2GB OCZ Gold 
Hard DriveOSMonitorPower
C300 128GB + Caviar Black 1TB Windows 7 Pro 64-Bit Samsung 23" 1080p 550W Antec Truepower 
CaseMouse
X-Clear Acrylic Case G500 
  hide details  
Reply
Cloaked
(13 items)
 
  
CPUMotherboardGraphicsRAM
i7 875k @ 4.0GHz Gigabyte GA-P55-UD3L Sapphire HD 4870 1GB Toxic 2 x 2GB OCZ Gold 
Hard DriveOSMonitorPower
C300 128GB + Caviar Black 1TB Windows 7 Pro 64-Bit Samsung 23" 1080p 550W Antec Truepower 
CaseMouse
X-Clear Acrylic Case G500 
  hide details  
Reply
post #8 of 27
sometimes it's not the chip, it's the mobo.
I have this same chip having hard time going pass 3.4 on a ECS POS P55 board and now running great volts @4 on the giga with good speed.
Main Rig V 6.8
(16 items)
 
  
CPUMotherboardGraphicsRAM
Intel Core i7 6850K @ 4.4Ghz Asus Rog Rampage V Extreme U3.1 GTX 1080 Ti @ 2050/6000 Corsair Vengance LPX 16GB DDR4-2800 
Hard DriveHard DriveHard DriveHard Drive
Intel 600P 512GB NVMe Samsung 850 PRO 256GB Samsung 850 EVO 500GB WD Caviar Black 640GB X2 
CoolingOSMonitorKeyboard
Corsair H115i AIO Windows 10 Pro x64 Philips BDM4350UC 4K Monitor 10bit + LG IPS231P Corsair K70 LUX CherryMX Brown 
PowerCaseMouseAudio
Corsair AX1200 80Plus Gold Thermaltake Core P3 Logitech G502 Proteus Core  ALC1150 Optical Out to Pioneer VSX-824-K 
  hide details  
Reply
Main Rig V 6.8
(16 items)
 
  
CPUMotherboardGraphicsRAM
Intel Core i7 6850K @ 4.4Ghz Asus Rog Rampage V Extreme U3.1 GTX 1080 Ti @ 2050/6000 Corsair Vengance LPX 16GB DDR4-2800 
Hard DriveHard DriveHard DriveHard Drive
Intel 600P 512GB NVMe Samsung 850 PRO 256GB Samsung 850 EVO 500GB WD Caviar Black 640GB X2 
CoolingOSMonitorKeyboard
Corsair H115i AIO Windows 10 Pro x64 Philips BDM4350UC 4K Monitor 10bit + LG IPS231P Corsair K70 LUX CherryMX Brown 
PowerCaseMouseAudio
Corsair AX1200 80Plus Gold Thermaltake Core P3 Logitech G502 Proteus Core  ALC1150 Optical Out to Pioneer VSX-824-K 
  hide details  
Reply
post #9 of 27
What mobo?
Lappy
(13 items)
 
  
CPUMotherboardGraphicsHard Drive
I5 2520M Dell Intel HD3000 Samsung 830 128GB SSD 
OSMonitor
Windows 7 Ultimate LED 
  hide details  
Reply
Lappy
(13 items)
 
  
CPUMotherboardGraphicsHard Drive
I5 2520M Dell Intel HD3000 Samsung 830 128GB SSD 
OSMonitor
Windows 7 Ultimate LED 
  hide details  
Reply
post #10 of 27
Thread Starter 
Whenever I run P95, I get temps around 63C; anyone recommend I just raise the vCore more to 1.375 because I have much more headroom for higher temps?
Cloaked
(13 items)
 
  
CPUMotherboardGraphicsRAM
i7 875k @ 4.0GHz Gigabyte GA-P55-UD3L Sapphire HD 4870 1GB Toxic 2 x 2GB OCZ Gold 
Hard DriveOSMonitorPower
C300 128GB + Caviar Black 1TB Windows 7 Pro 64-Bit Samsung 23" 1080p 550W Antec Truepower 
CaseMouse
X-Clear Acrylic Case G500 
  hide details  
Reply
Cloaked
(13 items)
 
  
CPUMotherboardGraphicsRAM
i7 875k @ 4.0GHz Gigabyte GA-P55-UD3L Sapphire HD 4870 1GB Toxic 2 x 2GB OCZ Gold 
Hard DriveOSMonitorPower
C300 128GB + Caviar Black 1TB Windows 7 Pro 64-Bit Samsung 23" 1080p 550W Antec Truepower 
CaseMouse
X-Clear Acrylic Case G500 
  hide details  
Reply
New Posts  All Forums:Forum Nav:
  Return Home
  Back to Forum: Intel CPUs
Overclock.net › Forums › Intel › Intel CPUs › i7 875k to 3.8GHz