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Overclocking 2500K, trying to understand weird behaviour

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CalsonicGTR

Member
Joined
Nov 6, 2001
Location
Illinois
I've been doing some overclocking today, and I've been noticing some weird behavior. While I'm stressing with Prime95, my multilplier will occasionally fluctuate (between 38 and 42). Is there a setting I need to disable to make this stop? Also, when I end the test CPU-Z shows that the multiplier drops to 16x, while every other program continues to show 42. Is this just a CPU-Z quirk?
 

4GHZ_or_bust

Now 6GHz or Bust!
Joined
Aug 1, 2002
Location
Michigan
Sounds like turbo boost is kicking in, then throttling back due to heat. I'd start with temp monitoring first to make sure you're not getting too hot.
 

GoD_tattoo

Member
Joined
Jul 30, 2009
Your power saving features are enabled. Don't know what they are on that board, but they used to be the C1E stuff.
 
OP
CalsonicGTR

CalsonicGTR

Member
Joined
Nov 6, 2001
Location
Illinois
Ok I disabled all of the C States (C1E, C3, C6) and Speedstep and tried again. Multiplier still fluctuates. Temps hit a max of 61/66/63/61 for all 4 cores with a 1.28 VCore. Im, using a Hyper 212+, are these temps high enough to activate the thermal throttling?
 

Dougshell

Member
Joined
Dec 27, 2009
bud had the same issue, tried a million settings and it ended up being a well known bios issue. Update fixed it (actually a roll back) this was on a MSI GD80 (B3)

Check your motherboard bios. His went from 47 down to 42 no matter what. Now he is rocking 50x100 at 5.0ghz
 

bennoculus

Member
Joined
Feb 7, 2011
Location
SoFla/Indiana
Ok I disabled all of the C States (C1E, C3, C6) and Speedstep and tried again. Multiplier still fluctuates. Temps hit a max of 61/66/63/61 for all 4 cores with a 1.28 VCore. Im, using a Hyper 212+, are these temps high enough to activate the thermal throttling?

Nope they are not. You need to be above 90C to throttle.
 

aaawew

Member
Joined
Oct 1, 2011
Location
Maine
Ok I disabled all of the C States (C1E, C3, C6) and Speedstep and tried again. Multiplier still fluctuates. Temps hit a max of 61/66/63/61 for all 4 cores with a 1.28 VCore. Im, using a Hyper 212+, are these temps high enough to activate the thermal throttling?

I had this problem too, try disabling spread spectrum i think this is what solved the problem for me :)
 

Neuromancer

Member
Joined
Oct 11, 2005
Location
Tau'ri
bud had the same issue, tried a million settings and it ended up being a well known bios issue. Update fixed it (actually a roll back) this was on a MSI GD80 (B3)

Check your motherboard bios. His went from 47 down to 42 no matter what. Now he is rocking 50x100 at 5.0ghz

I ran into it on MSI too had to do with "overclocking enabled" setting or something that was not working.

On asustek boards, sounds more like you are hitting current limits, not thermals. You can try setting current limits to 1110-120% of physically entering AMPs in the long/short mode of the turbo advanaced menu.
 

aaawew

Member
Joined
Oct 1, 2011
Location
Maine
Ok I disabled all of the C States (C1E, C3, C6) and Speedstep and tried again. Multiplier still fluctuates. Temps hit a max of 61/66/63/61 for all 4 cores with a 1.28 VCore. Im, using a Hyper 212+, are these temps high enough to activate the thermal throttling?

The multiplier should not go to x16 if you have disabled C states, C1E, C3, and C6 and speedstep. as for it going from 42-38 that problem like i said above should be fixed with disabling spreadspectrum :)
 

YOO

Member
Joined
Oct 3, 2004
Location
Central Nebraska US
sorry if hijacked this thread but i just notice i have the same problem as CalsonicGTR. i have the same board but its just a full atx.

i do have all C states disabled, turbo disabled, spreadspectrum disabled, and speedstep disabled.

did the maximum test with IBT and multi drops to x34 :(. any more ideas? this is my first OC.

EDIT: core current limit is at 150. gonna try 200. ill be back with results

it didnt work. im out of ideas :(
 
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aaawew

Member
Joined
Oct 1, 2011
Location
Maine
sorry if hijacked this thread but i just notice i have the same problem as CalsonicGTR. i have the same board but its just a full atx.

i do have all C states disabled, turbo disabled, spreadspectrum disabled, and speedstep disabled.

did the maximum test with IBT and multi drops to x34 :(. any more ideas? this is my first OC.

EDIT: core current limit is at 150. gonna try 200. ill be back with results

it didnt work. im out of ideas :(

So you tried disabling spread spectrum and it still dropped? (i set all the core current limits to 300 along with the CPU max core or what ever that setting is)
When I get home and look at all of my notes from trying overclocks and see what i have disabled and see if i can figure out what fixed my multiplier from dropping under load :D
 

manu2b

Member
Joined
Feb 6, 2011
^^ Set power limit to manual and then short and long duration to 300 and you'll be good to go.
Set core current limit to 300 as well.
 

YOO

Member
Joined
Oct 3, 2004
Location
Central Nebraska US
my temps are in the low to mid 60's under load. i set current limit to 300 but i could not find power limit on bios. unless, it is called something else in mine :shrug:
 

aaawew

Member
Joined
Oct 1, 2011
Location
Maine
my temps are in the low to mid 60's under load. i set current limit to 300 but i could not find power limit on bios. unless, it is called something else in mine :shrug:

Do you see turbo boost power limit? it should be set to auto and if you set it to manual it should give you two options, long duration power limit and short duration power limit
 

YOO

Member
Joined
Oct 3, 2004
Location
Central Nebraska US
ok, i enabled speedstep and found turbo boost power limit and set it to manual.
set long and short to 300. gonna test!

edit: tested with those settings and stays at 42x. it does go back to x16 after is done. normal? i thought disabling C states would make it stayed OC.

one other thing, i was checking my temps while stress testing with HWmonitor and the temp would fluctuate from like 62c to 71c on all cores. which temp is right?
 
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manu2b

Member
Joined
Feb 6, 2011
It's normal that it goes back to 16x, that's some power saving option (speedstep actually).

Temps fluctuate, that's normal. And they are different from one core to the other.
Ideally a 5°C range, but that can reach 10°C.

The better the TIM apllied and the heatsink seated, the lower the delta between cores, but you'll always get a 4/5°C difference.
 

YOO

Member
Joined
Oct 3, 2004
Location
Central Nebraska US
well so far so good. i did notice that when i run IBT core temps go up to 70c. and, when running prime95, temps stay around 60c. im guessing IBT is more stressful on cpu?
 

Theocnoob

Member
Joined
Dec 1, 2007
Location
Near Toronto Canada
well so far so good. i did notice that when i run IBT core temps go up to 70c. and, when running prime95, temps stay around 60c. im guessing IBT is more stressful on cpu?

Yes IBT is 10 degrees or so more stress almost than P95 if you set IBT on high. This is normal.

Update to the latest bios and just follow the advice as it comes. Sounds like you're well on your way to a solution and understand what's goin on :thup: