Overclock.net › Forums › Intel › Intel CPUs › Voltage Fluctuation & CPU Health
New Posts  All Forums:Forum Nav:

Voltage Fluctuation & CPU Health

post #1 of 2
Thread Starter 
So, thought experiment here. I have a CPU. It clocks at 5 ghz @ 1.5Vcore. Obviously, that is a somewhat high voltage, so we don't want to be stuck at 1.5 all day. Since it doesn't usually need to run at full load, it dynamically underclocks itself to as low as 1 ghz, running at 1.0V at absolute idle. When the load varies, the clockspeed and voltage can vary in between these values. However, even while idling, the Vcore rarely stays at 1.0; it does spike and fluctuate a lot as well.

I'm thinking - what would be better for the health of the CPU? To have a 1.0V baseline and fluctuate between that and 1.5V? Or to have a 1.2V baseline? Or even 1.3?

Thoughts? Science? Opinions?
I hate my CPU
(11 items)
 
  
CPUMotherboardGraphicsRAM
2500k | 4.7 Asrock Extreme3 Gen3 XFX 7970  Mushkin 1333 9-9-9-24 (2x4) 
Hard DriveHard DriveOSPower
Seagate 1TB Samsung 840 Pro, 256 Win 7 x64 Corsair HX750 
Case
Coolermaster CM 690 
  hide details  
Reply
I hate my CPU
(11 items)
 
  
CPUMotherboardGraphicsRAM
2500k | 4.7 Asrock Extreme3 Gen3 XFX 7970  Mushkin 1333 9-9-9-24 (2x4) 
Hard DriveHard DriveOSPower
Seagate 1TB Samsung 840 Pro, 256 Win 7 x64 Corsair HX750 
Case
Coolermaster CM 690 
  hide details  
Reply
post #2 of 2

The fluctuation is normal, and there's actually a lot more fluctuation than any software can show us.  If we were able to see exactly how much fluctuation there really is, then we would probably panic and then faint.  ;)

 

I think I don't know much, so my feelings are that it seems best to allow the CPU to downclock to 1.6 GHz and to downvolt to the 1.0V range.  I also have C3 and C6 enabled, but I can get away with this because I'm also using 25% LLC (Medium for my ASUS board, so probably level 4 or so for you).  This means that when my CPU is truly idling and has entered the C6 state, it's not consuming any power at all - it's actually sitting at 0V.  However, software like CPU-Z can't show this because it has to keep at least one core awake which means it's going to be showing that one core sitting in the 1.0V range.

 

So yeah, I guess I prefer an Offset voltage, 25% LLC, C3 and C6 enabled (C1E and SpeedStep enabled too), and there's something else I forgot to mention:  I have my power plan in Windows customized so that my minimum processor state is 0%, and my maximum is, of course, at 100%.  I don't know if this makes any difference, but it's not hurting anything.

 

By enabling C3 and C6, I saw a ~15W reduction in my idle power consumption. 

It's a computer!
(19 items)
 
  
CPUMotherboardGraphicsRAM
i5-2500K @ 4.5GHz (1.368-1.384V fixed voltage) ASUS P8P67 EVO B3 (UEFI ver. 1850) GTX 780 ASUS DirectCU II (1228 / 6300, 1.180V) G.SKILL Ripjaws X 8GB (2 x 4GB) 1866MHz, CL9 
Hard DriveHard DriveHard DriveOptical Drive
250 GB Samsung 840 EVO (C:\) 250 GB Samsung 840 EVO (D:\) 150 GB WD VelociRaptor Samsung SH-S243N 24x DVD Burner 
Optical DriveCoolingOSMonitor
Samsung SH-S203N 20X DVD Burner Thermaltake Frio Win 7 Home Premium x64 SP1 Retail AOC G2460PG (24" 1920 x 1080 144Hz G-SYNC) 
KeyboardPowerCaseMouse
Filco Majestouch 104-key Cherry MX Blues w/NKRO Corsair HX650 (Bronze, ordered on 12-12-2009) CM 690 Intellimouse Optical (1.1A) 1000Hz polling rate 
Mouse PadAudioAudio
Basic, but premium round X-Fi Titanium HD Klipsch ProMedia 2.1 (with 16 AWG Monster Cable... 
  hide details  
Reply
It's a computer!
(19 items)
 
  
CPUMotherboardGraphicsRAM
i5-2500K @ 4.5GHz (1.368-1.384V fixed voltage) ASUS P8P67 EVO B3 (UEFI ver. 1850) GTX 780 ASUS DirectCU II (1228 / 6300, 1.180V) G.SKILL Ripjaws X 8GB (2 x 4GB) 1866MHz, CL9 
Hard DriveHard DriveHard DriveOptical Drive
250 GB Samsung 840 EVO (C:\) 250 GB Samsung 840 EVO (D:\) 150 GB WD VelociRaptor Samsung SH-S243N 24x DVD Burner 
Optical DriveCoolingOSMonitor
Samsung SH-S203N 20X DVD Burner Thermaltake Frio Win 7 Home Premium x64 SP1 Retail AOC G2460PG (24" 1920 x 1080 144Hz G-SYNC) 
KeyboardPowerCaseMouse
Filco Majestouch 104-key Cherry MX Blues w/NKRO Corsair HX650 (Bronze, ordered on 12-12-2009) CM 690 Intellimouse Optical (1.1A) 1000Hz polling rate 
Mouse PadAudioAudio
Basic, but premium round X-Fi Titanium HD Klipsch ProMedia 2.1 (with 16 AWG Monster Cable... 
  hide details  
Reply
New Posts  All Forums:Forum Nav:
  Return Home
  Back to Forum: Intel CPUs
Overclock.net › Forums › Intel › Intel CPUs › Voltage Fluctuation & CPU Health