Overclock.net › Forums › Intel › Intel CPUs › C-states causing instability @ 4.2 GHz
New Posts  All Forums:Forum Nav:

C-states causing instability @ 4.2 GHz

post #1 of 4
Thread Starter 
just wondering if anyone has has a trick up their sleeve for enabling c-states and keeping stability at over 4.0 GHz on an i7 9xx chip....

4.0 GHz is fine with c-states on and can run prime blend 24/7....with 16 GB of ripjaws 1600 at 9-9-9-24 @ 1.64 v ............

v core-1.28 v
PLL-1.84 v
QPI/DRAM-1.3 v

pushing to 4.2 is stable (when i disable c-states) with following settings

V core-1.32 v
PLL-1.86 v
QPI/DRAM-1.35 v

ram is kept the same...

i have to disable c-states for any sort of stability at 4.2 GHz .... any reason why ......or what should be changed to keep 4.2 GHz and be able to enable c-states while keeping stability would be much appreciated.


all hardware is in my signature....

if anyone has any ideas they are much appreciated.......i have spent weeks trying to get my idle temps down at 4.2....

sorry for any bad grammar or spelling as i am a bit drunk cheers.gif ...
 
The Mrs' Gamer
(15 items)
 
PLEX
(17 items)
 
CPUMotherboardGraphicsRAM
i3 2120 (STOCK) p8H61 Sapphire HD 7950 8GB (2 X 4GB) Kingston 1333Mhz  
Hard DriveOptical DriveCoolingOS
Seagate Multi DVD fan Windows 10 Pro 
MonitorKeyboardPowerCase
Viewsonic 4:3 Logitech wireless 600W thermaltake quiet Asus CM6730 
MouseMouse PadAudio
Microsoft Wired 3500 Asus ROG Promo Monitor Speakers 
CPUMotherboardGraphicsRAM
AMD A10 6700 MS-7778 (JasmineR) Radeon HD 8570 16 GB DDR3-1600 (2 X 8GB) 
Hard DriveOptical DriveCoolingOS
3 TB SuperMulti DVD Burner drive Stock Win 8.1 Home 
MonitorKeyboardPowerCase
KDL-40EX650 Flirc Stock Stock 
MouseMouse PadAudioOther
Cheap Logitech none HT-DDW1500 2TB ext drive 
Other
2TB ext drive 
  hide details  
Reply
 
The Mrs' Gamer
(15 items)
 
PLEX
(17 items)
 
CPUMotherboardGraphicsRAM
i3 2120 (STOCK) p8H61 Sapphire HD 7950 8GB (2 X 4GB) Kingston 1333Mhz  
Hard DriveOptical DriveCoolingOS
Seagate Multi DVD fan Windows 10 Pro 
MonitorKeyboardPowerCase
Viewsonic 4:3 Logitech wireless 600W thermaltake quiet Asus CM6730 
MouseMouse PadAudio
Microsoft Wired 3500 Asus ROG Promo Monitor Speakers 
CPUMotherboardGraphicsRAM
AMD A10 6700 MS-7778 (JasmineR) Radeon HD 8570 16 GB DDR3-1600 (2 X 8GB) 
Hard DriveOptical DriveCoolingOS
3 TB SuperMulti DVD Burner drive Stock Win 8.1 Home 
MonitorKeyboardPowerCase
KDL-40EX650 Flirc Stock Stock 
MouseMouse PadAudioOther
Cheap Logitech none HT-DDW1500 2TB ext drive 
Other
2TB ext drive 
  hide details  
Reply
post #2 of 4
No tricks with my results either raise vcore to a higher value to.keep.cstates on or disable c3 and c6 and keep.it at a lower voltage I was able to.do 1.168 at 4.2 with all power saving on even at 4.5 I could t0o, you will just need more vcore than if you didn't use c3 and c6
Edited by enigma7820 - 2/20/13 at 12:55pm
post #3 of 4
When you enable C3 or C6 on a first generation Core i7-920, you will be unlocking the 22 multiplier. Some long time i7-920 owners have no idea this is built into their CPUs.

The 22 multiplier is only available when a single core is active. When 2, 3 or 4 cores are active, the maximum multiplier is 21 but it can go as high as 22 when a single core is in the active state.

This is probably how C3 and C6 originally got a bad reputation. You can't just take a stable overclock and turn on C3 or C6 and expect everything to be more or less the same. If you were running stable at 21 x 200, now the CPU is going to be jumping up randomly to 22 x 200. Good bye stability.

On the i7-920, there is no way to control this. You could turn off Turbo Boost but then your maximum multiplier is only 20. The 21 multiplier is only available when Turbo Boost in the CPU is enabled. There is no way to enable C3 or C6 and limit the multiplier to only 21.
post #4 of 4
Thread Starter 
thanks guys, i will just use C1E as it still down clocks and saves some temp when its not doing much and have now tested as 24hrs prime blend stable with 4.2 Ghz and C1E enabled.

thanks for the advice. thumb.gif
 
The Mrs' Gamer
(15 items)
 
PLEX
(17 items)
 
CPUMotherboardGraphicsRAM
i3 2120 (STOCK) p8H61 Sapphire HD 7950 8GB (2 X 4GB) Kingston 1333Mhz  
Hard DriveOptical DriveCoolingOS
Seagate Multi DVD fan Windows 10 Pro 
MonitorKeyboardPowerCase
Viewsonic 4:3 Logitech wireless 600W thermaltake quiet Asus CM6730 
MouseMouse PadAudio
Microsoft Wired 3500 Asus ROG Promo Monitor Speakers 
CPUMotherboardGraphicsRAM
AMD A10 6700 MS-7778 (JasmineR) Radeon HD 8570 16 GB DDR3-1600 (2 X 8GB) 
Hard DriveOptical DriveCoolingOS
3 TB SuperMulti DVD Burner drive Stock Win 8.1 Home 
MonitorKeyboardPowerCase
KDL-40EX650 Flirc Stock Stock 
MouseMouse PadAudioOther
Cheap Logitech none HT-DDW1500 2TB ext drive 
Other
2TB ext drive 
  hide details  
Reply
 
The Mrs' Gamer
(15 items)
 
PLEX
(17 items)
 
CPUMotherboardGraphicsRAM
i3 2120 (STOCK) p8H61 Sapphire HD 7950 8GB (2 X 4GB) Kingston 1333Mhz  
Hard DriveOptical DriveCoolingOS
Seagate Multi DVD fan Windows 10 Pro 
MonitorKeyboardPowerCase
Viewsonic 4:3 Logitech wireless 600W thermaltake quiet Asus CM6730 
MouseMouse PadAudio
Microsoft Wired 3500 Asus ROG Promo Monitor Speakers 
CPUMotherboardGraphicsRAM
AMD A10 6700 MS-7778 (JasmineR) Radeon HD 8570 16 GB DDR3-1600 (2 X 8GB) 
Hard DriveOptical DriveCoolingOS
3 TB SuperMulti DVD Burner drive Stock Win 8.1 Home 
MonitorKeyboardPowerCase
KDL-40EX650 Flirc Stock Stock 
MouseMouse PadAudioOther
Cheap Logitech none HT-DDW1500 2TB ext drive 
Other
2TB ext drive 
  hide details  
Reply
New Posts  All Forums:Forum Nav:
  Return Home
  Back to Forum: Intel CPUs
Overclock.net › Forums › Intel › Intel CPUs › C-states causing instability @ 4.2 GHz