Turbo boost on i5-2500k

z1ggy

Lifer
May 17, 2008
10,004
63
91
Hi,

I recently got the i3-2100 on a promo deal on TG for $85. A friend of mine said he would buy it from me for $100...So I am considering now just spending a bit of extra cash for the k series. If I OC this from 3.3 to 4.0, does the turbo now increase speeds to 4.4? Or is null because the idle OC freq. is now higher than the turbo w/o the OC? Thanks for your time.
 

Ken g6

Programming Moderator, Elite Member
Moderator
Dec 11, 1999
16,242
3,830
75
I gather that with the K series you can either boost the turbo speed, or change the base speed, or both! Either can be set to up to 5.7GHz, or however high your system is stable. If you just boost the turbo speed, light loads will stay at 3.3GHz, and only when your CPU is fully-loaded (such as by a game or OC testing tool) will it go to whatever turbo speed you set it to.

Edit: P.S. You have a cheap processor; what chipset (P67, H67, or Z68) do you have? H67 motherboards don't allow K-series overclocking!
 
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d4a2n0k

Senior member
May 6, 2002
375
0
76
The 2nd gen Core CPU's overclock differently. You set the turbo ratio limit and the CPU ramps up to that speed when needed using the turbo feature. If you set it at 46 x 100, it will not turbo up to 50 x 100, you set the limit. You have to keep turbo enabled to overclock.

For the 1st gen Core CPU's, you would normally disable turbo and set the BCLK. If you did enable turbo, it would turbo +200 mhz over whatever setting you chose.
 

StrangerGuy

Diamond Member
May 9, 2004
8,443
124
106
I gather that with the K series you can either boost the turbo speed, or change the base speed, or both! Either can be set to up to 5.7GHz, or however high your system is stable. If you just boost the turbo speed, light loads will stay at 3.3GHz, and only when your CPU is fully-loaded (such as by a game or OC testing tool) will it go to whatever turbo speed you set it to.

Edit: P.S. You have a cheap processor; what chipset (P67, H67, or Z68) do you have? H67 motherboards don't allow K-series overclocking!

Overclocking via BLK is dead with SB.
 

Crap Daddy

Senior member
May 6, 2011
610
0
0
On SB unlocked you can set the turbo limit by changing the multiplier. So if you set that to 40, the max turbo on all cores is 4Ghz. You don't touch the BCLK which is set at 100MHz. With speedstep and all C states enabled the CPU is clocked at 1600MHz at idle/desktop and when needed it goes up to the value you set. By default the 2500K runs in tubo mode at 3,7 on one core (rarely you'll see that), 3,6 on 2 cores, 3,5 on 3 cores and 3,4 on all.
 

toyota

Lifer
Apr 15, 2001
12,957
1
0
On SB unlocked you can set the turbo limit by changing the multiplier. So if you set that to 40, the max turbo on all cores is 4Ghz. You don't touch the BCLK which is set at 100MHz. With speedstep and all C states enabled the CPU is clocked at 1600MHz at idle/desktop and when needed it goes up to the value you set. By default the 2500K runs in tubo mode at 3,7 on one core (rarely you'll see that), 3,6 on 2 cores, 3,5 on 3 cores and 3,4 on all.
well if you raise the turbo from 3.7 to 4.0 doesn't that mean it will still only do that on one core?
 

BonzaiDuck

Lifer
Jun 30, 2004
15,709
1,450
126
I gather that with the K series you can either boost the turbo speed, or change the base speed, or both! Either can be set to up to 5.7GHz, or however high your system is stable. If you just boost the turbo speed, light loads will stay at 3.3GHz, and only when your CPU is fully-loaded (such as by a game or OC testing tool) will it go to whatever turbo speed you set it to.

Edit: P.S. You have a cheap processor; what chipset (P67, H67, or Z68) do you have? H67 motherboards don't allow K-series overclocking!

I'm goin' real slow with this -- trying to think it through before doing something. I agree with your first sentence there -- I'm guessing (and hoping with confidence . . ) that I can set the base speed on my 2600K to something closer to between 3.8 and 4.0 Ghz, and the Turbo limit at maybe 4.3 or 4.4. these may seem like pussy over-clocks, as some of the Supreme Xtremes out there are trying to push past 5.0. I'm just getting started -- may fiddle with it for a few months before decommissioning my "main machine" and moving software and files to this one .. .

But this seems really elegant to me: To enable EIST and the C states, have the idle and load speeds supported by a dynamic voltage on "auto," and even -- maybe -- be able to keep it stable so that it can go into an S3 sleep-state and then come out unscathed.

I mean . . . . rather than breaking records . . . . what more would you ask for in a Dream Machine?
 

z1ggy

Lifer
May 17, 2008
10,004
63
91
I gather that with the K series you can either boost the turbo speed, or change the base speed, or both! Either can be set to up to 5.7GHz, or however high your system is stable. If you just boost the turbo speed, light loads will stay at 3.3GHz, and only when your CPU is fully-loaded (such as by a game or OC testing tool) will it go to whatever turbo speed you set it to.

Edit: P.S. You have a cheap processor; what chipset (P67, H67, or Z68) do you have? H67 motherboards don't allow K-series overclocking!

ASRock Z68.
 

toyota

Lifer
Apr 15, 2001
12,957
1
0
No. This will be the turbo value whenever it's needed on whatever cores.
well that does not make sense. if the turbo only goes to 3.7 on one core then how does simply raising it to 4.0 make it go that high on all cores?
 

StrangerGuy

Diamond Member
May 9, 2004
8,443
124
106
well that does not make sense. if the turbo only goes to 3.7 on one core then how does simply raising it to 4.0 make it go that high on all cores?

SB turbo is individually set for 1/2/3/4 cores.

If you put 44x / 43x / 42x / 41x then your SB chip will up to 4.4GHz on only one-core, 4.3GHz on two cores etc.
 

toyota

Lifer
Apr 15, 2001
12,957
1
0
SB turbo is individually set for 1/2/3/4 cores.

If you put 44x / 43x / 42x / 41x then your SB chip will up to 4.4GHz on only one-core, 4.3GHz on two cores etc.
well lets say that you do want to go above 4.2 because you do want use more than stock voltage. if you set it to 4.2 then that would only be for 1 core? so you can not just make it go to 4.2 for all 4 cores without it going over that for 3, 2, or 1 core?
 

Nemesis 1

Lifer
Dec 30, 2006
11,366
2
0
I am running 2500K as my browser/ Turbo is NOT running and my O/C is at 4.5 . My V core is at 1.352. and all 4 cores are @ 4.5GHZ. When in use. SO no turbo here but a nice O/C at what I consider low voltage. CE and C states are on . Idle temps 29-31C.
 

toyota

Lifer
Apr 15, 2001
12,957
1
0
is there an in depth article somewhere that explains in detail how to oc the 2500k/2600k cpus? I want to know everything about how turbo and everything else works. yes I know I could google it but if there is a recommended article somewhere that would be great.
 

Nemesis 1

Lifer
Dec 30, 2006
11,366
2
0
Since you guys are talking about Turbo mode this is a nice little add on that you can run that will tell you when and to what the Turbo mode clocks to http://downloadcenter.intel.com/Detail_Desc.aspx?agr=Y&DwnldID=19105.

Christain Wood
Intel Enthusiast Team

This is a really neat tool . It really helps to dial in your system. This and Temps . I really pleased with this chip(2500k) its better than my 2600K as far as lower voltage at same overclock. But I run the 2600K at 5ghz. on water. and I very happy with its voltage. But its a differant Kind of overclock than what I use on the 2500k.
 

StrangerGuy

Diamond Member
May 9, 2004
8,443
124
106
well lets say that you do want to go above 4.2 because you do want use more than stock voltage. if you set it to 4.2 then that would only be for 1 core? so you can not just make it go to 4.2 for all 4 cores without it going over that for 3, 2, or 1 core?

Most people would just use 44/44/44/44x to get 4.4GHz regardless of core utilization.

Stock voltages for SB does not have a upper fixed limit. According to CPU-Z the chip would start to request increasingly higher Vcore as you dial up the turbo multipliers. If you just want to play it simple for OC you just use a fixed Vcore, but I reckon your idle power consumption would be higher as EIST won't be able to drop Vcore during idle.
 

MrTransistorm

Senior member
May 25, 2003
311
0
0
Most people would just use 44/44/44/44x to get 4.4GHz regardless of core utilization.

Stock voltages for SB does not have a upper fixed limit. According to CPU-Z the chip would start to request increasingly higher Vcore as you dial up the turbo multipliers. If you just want to play it simple for OC you just use a fixed Vcore, but I reckon your idle power consumption would be higher as EIST won't be able to drop Vcore during idle.
Exactly. And there's no reason to disable all of the power-saving features and using a fixed Vcore unless you're going for a very high OC. I have even gotten my 2600K stable at 5GHz with EIST, C1e, HT, and turbo enabled with a dynamic Vcore. This series of CPUs completely rewrites the usual methods of OC'ing.
 

Nemesis 1

Lifer
Dec 30, 2006
11,366
2
0
Most people would just use 44/44/44/44x to get 4.4GHz regardless of core utilization.

Stock voltages for SB does not have a upper fixed limit. According to CPU-Z the chip would start to request increasingly higher Vcore as you dial up the turbo multipliers. If you just want to play it simple for OC you just use a fixed Vcore, but I reckon your idle power consumption would be higher as EIST won't be able to drop Vcore during idle.

On the Z68 M/Bs we have In the bias Whats referred a Vdrop function were when its engaged it doesn;t allow the Vdrop to drop off as much if your Fixed Vcore with all the power saving features turned on. I was using all auto setting at first other than the multipler. 45x on the 2500k. But it wouldn't boot until I disable Cstate . On a browser thats abit of a concern for me . So I walked threw it in my mind the flow metheds intel was using on this chip. I knew the chip would do 4.5ghz easily . Than I realized the problem with Cstate . I needed to Fix the voltage knowing full well that Voltage is only used at !100% when the demand is there. So I decided to fix @ 1.37 and this chip has never run at the Voltage It in fact runs at 1.352 (Test points) all the time . Except when its under load than it drops voltage to around 1.300 Now this I seen to be the problem . I engaged the Vdrop control so it wouldn't drop off so much . Now underload It drops to 1.344v.
That allowed me to turn on Cstate(6) which drops my idling temps by between 9/10 degrees C. from 40c down to 30/31@ idle . Now on a browser /gamer. Thats a big deal when you engage Virtu in Imode. If power wasn't a concern I wouldn't run Virtu. So I really pleased with hows this as a system works . Than I am using a Intel 510/120 sata III. So the responsiveness Of this setup for the power it uses is truely remarkable.
 
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