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decreasing voltage on 955

post #1 of 12
Thread Starter 
Hello all,

I overclocked my 955 to ~3.6ghz by increasing the multiplier to x18 and the nb frequency to 2200. I upped the CPU NB frequency to 1.15 while my CPU voltage is still at default (1.4v). I've set everything in the bios to manual as opposed to auto.

My question: is it feasible to lower the voltage to say 1.35 or 1.38? My temps running prime95 are 58c max. This with the stock cooler. I'm slightly concerned about the temperature, even if no practical application utilizes 100% on all four cores. I've heard people reaching 3.6ghz with CM2 stock voltage (1.35). Will lowering my voltage help decrease temps? OR should i just leave it at stock.

I will be installing hyper 212+ cooler this Friday, so hopefully my temps fall anyway. My goal is 3.8+ which according to my research should be attainable with 1.4-1.5v.

Also, is there any chart that details nb frequency scaling with voltage? Is 1.15 good for 2200mhz?

Sorry for the barrage of questions. First post and i have a lot to learn. Thank you.
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G.Skill Ripjaw 8g 1600mhz  Samsung Spinpoint F3 1tb n/a Cooler Master Hyper 212+ 
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post #2 of 12
Lowering your voltage will decrease temps, start dropping it by 0.001v at time to find your lowest stable voltage - every chip is different and will require different voltage for set clocks - you must find yours. Make sure you are looking at "Core Temp" under load - see my guide for more information.
post #3 of 12
Easiest way to find your lowest stable voltage is to go by the smallest increment possible, until you cannot boot anymore. Then bump it until you're Prime95 stable.

It all depends on how good your chip is, if it's any good, you should get it at low as 1.3v.
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post #4 of 12
Thread Starter 
Thanks guys. I can't go .001 but i'll try the smallest increments. Then again, with my new cooler coming, i might keep it at 1.4 and try to get a higher overclock. decisions decisions.....
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G.Skill Ripjaw 8g 1600mhz  Samsung Spinpoint F3 1tb n/a Cooler Master Hyper 212+ 
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Windows 7 x64 Some old Acer 1440x900 Sidewinder X4 Antec Earthwatts 750 
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RAMHard DriveOptical DriveCooling
G.Skill Ripjaw 8g 1600mhz  Samsung Spinpoint F3 1tb n/a Cooler Master Hyper 212+ 
OSMonitorKeyboardPower
Windows 7 x64 Some old Acer 1440x900 Sidewinder X4 Antec Earthwatts 750 
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post #5 of 12
You'll never hear me say "nah your fine" when it comes to overclocking
post #6 of 12
Thread Starter 
i guess overclockers are never satisfied. always burdened by that extra .1 in v, ghz, mhz etc...
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RAMHard DriveOptical DriveCooling
G.Skill Ripjaw 8g 1600mhz  Samsung Spinpoint F3 1tb n/a Cooler Master Hyper 212+ 
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Windows 7 x64 Some old Acer 1440x900 Sidewinder X4 Antec Earthwatts 750 
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Phenom II 955 CM3 @ 4.0ghz  Gigabyte GA-990FXA-UD3 XFX 6870 XFX 6870  
RAMHard DriveOptical DriveCooling
G.Skill Ripjaw 8g 1600mhz  Samsung Spinpoint F3 1tb n/a Cooler Master Hyper 212+ 
OSMonitorKeyboardPower
Windows 7 x64 Some old Acer 1440x900 Sidewinder X4 Antec Earthwatts 750 
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post #7 of 12
Exactly, it gets to the point where 100Mhz extra isn't going to increase performance to where you'd even notice it, but it's bragging rights - right?
post #8 of 12
@OP


My 955 is running at 3.7~Ghz (at the moment) at 1.3875v. That's just an estimate for you. I am able to run 3.6Ghz at 1.3375.
    
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post #9 of 12
My chip is by no means golden. It can do stock 3.2 @ 1.25V, and 3.6 @ 1.35. I have it set now to 3.87GHz and 1.375. The 955's are really good chips.
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CPUMotherboardGraphicsRAM
Intel i7 4770k Gigabyte z97x-soc force XFX R7 260X Crucial Ballistix Sport LP  
Hard DriveHard DriveCoolingCooling
Crucial M500 Seagate  EK-KIT L120 Swiftech MCR-H220 
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Arch Linux x86-64 HP E201 Cooler Master Rapid-i mx red/green led EVGA SuperNOVA 850B2 
CaseMouseMouse PadAudio
Corsair C70 Perixx MX-1800R Something from Radio Shack Altec Lansing 2.1 
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HP 2009m Noppoo Lolita 87 Corsair HX650 Cooler Master Haf 912 
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AMD Opteron 185 DFI LANPARTY UT nF4 SLI-DR Expert EVGA 8800 GTS Corsair XMS-4000PT DDR500 
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post #10 of 12
Thread Starter 
Quote:
Originally Posted by z3r0_k00l75 View Post
The 955's are really good chips.
Indeed they are. I think I'm going to be AMD for life. for $120 they are a steal.

Thanks to everyone who replied. Since my cooler arrived, I think I'm going to leave the voltages as they are and push my system harder. But it's good to know voltage/overclock links. Next up, NB and CPU NB voltages lol.

I'll post my final overclocks to the phenom 955 overclock oc club and here. One last question, do you think my temps are ok as of now? or should i back off?
Main Rig
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CPUMotherboardGraphicsGraphics
Phenom II 955 CM3 @ 4.0ghz  Gigabyte GA-990FXA-UD3 XFX 6870 XFX 6870  
RAMHard DriveOptical DriveCooling
G.Skill Ripjaw 8g 1600mhz  Samsung Spinpoint F3 1tb n/a Cooler Master Hyper 212+ 
OSMonitorKeyboardPower
Windows 7 x64 Some old Acer 1440x900 Sidewinder X4 Antec Earthwatts 750 
CaseMouseMouse PadAudio
Cooler Master Storm Scout Gigabyte M6980 steelseries qck Focusrite Saffire 6 
Other
Creative Labs Alpha Sigma Headphones 
  hide details  
Reply
Main Rig
(17 items)
 
  
CPUMotherboardGraphicsGraphics
Phenom II 955 CM3 @ 4.0ghz  Gigabyte GA-990FXA-UD3 XFX 6870 XFX 6870  
RAMHard DriveOptical DriveCooling
G.Skill Ripjaw 8g 1600mhz  Samsung Spinpoint F3 1tb n/a Cooler Master Hyper 212+ 
OSMonitorKeyboardPower
Windows 7 x64 Some old Acer 1440x900 Sidewinder X4 Antec Earthwatts 750 
CaseMouseMouse PadAudio
Cooler Master Storm Scout Gigabyte M6980 steelseries qck Focusrite Saffire 6 
Other
Creative Labs Alpha Sigma Headphones 
  hide details  
Reply
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