# E8400 overclock @4GHz: Is it worth it?



## MatTheCat (Mar 23, 2010)

Having upgraded my gfx card from a 4870 to a 5850, I heeded someones advice (on this forum, I forget who), to push my E8400 CPU up to 4GHz (from 3.85GHz).

However, to attain this I had to push my vCore (CPU coltage) up from 1.306v, to 1.35v. Quite a few step ups in voltage increments to acheive an extra 150MHz on the clock. Furthermore, the benchmarks I am using (Heaven and 3dMark06) are indicating that I am not getting particulary overly fantastic performance improvements for putting all these extra volts through my CPU.

Please could someone explain to me why it is beneficial to have an E8400 running at 4GHz over say 3.85GHz or even 3.6GHz? Like I say, I decided in the past that 4GHz wasn't worth it but someone on here said that because I was getting a 5850, that I should push CPU to 4GHz


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## trickson (Mar 23, 2010)

You will not see much of a difference from 3.8GHz to 4.0 GHz but you will see it in benchmarks is all . I would push that CPU as high as you can , I mean what is the point of doing some thing half ass and later say I could do this . Hell mine is running flat out @ 4.2GHz 1.45 Vcore . Hell if it breaks get a new one  , I say .


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## Goodman (Mar 23, 2010)

From 3.6GHz to 4GHz yeah! 
but if you're already at 3.85GHz then no , you won't notice much difference maybe 1-2 fp/s more in games 

I'll say keep it the way it is it's fast enough


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## qubit (Mar 23, 2010)

My E8500 (3.16GHz stock) is running at 4.11GHz 24/7 and is wickedly fast. Now that might not be that much faster than 3.8GHz, but as they say, every little helps. Helpfully, mine is an E0 stepping that overclocks like this easily, without strain. If you have to nail yours to the wall to achieve this performance, then it's probably not worth it.

I even got it up to 4.8GHz when new, to see how far I could go. However, my air cooling (Zalman 7700) wasn't sufficient to keep the temperature in check and it was hitting 80C+ even with the fan at full blast. It's very stable, however. With proper water cooling, this thing could do 5GHz.


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## ZenEffect (Mar 23, 2010)

3.85 to 4 isnt that big of a jump... i guess it really depends on how temps are at 1.35v.  if temps are good i say go for it.


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## Black Panther (Mar 23, 2010)

To know whether it's worth or not keep an eye on the temperatures when both cores are at 100% load. If it doesn't go over 60 C then it's worth. If it goes over... well it isn't worth having your cpu throttle down while playing a cpu-intensive game is it?

I run my E8400 at 4Ghz myself, on air. While on the net I'm crunching at 100% cpu usage. If I'm not crunching I'd be gaming. 

Unless I'm mistaken the max vcore for the E8400 according to intel is 1.45
I put mine at 1.3275 in the bios, and vdroop from the mobo drops it to lower than 1.2 at load. But so far so good it's been running like this for long months now with no problems at all.
Definitely don't try over 1.45V though.


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## trickson (Mar 23, 2010)

Yeah do not go over that 1.45 mark not good for the CPU .


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## Sasqui (Mar 23, 2010)

What are you hitting for a FSB?

I've had my E8600 over 5 Ghz, gotta love that 10x multiplier


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## ZenEffect (Mar 23, 2010)

Black Panther said:


> To know whether it's worth or not keep an eye on the temperatures when both cores are at 100% load. If it doesn't go over 60 C then it's worth. If it goes over... well it isn't worth having your cpu throttle down while playing a cpu-intensive game is it?
> 
> I run my E8400 at 4Ghz myself, on air. While on the net I'm crunching at 100% cpu usage. If I'm not crunching I'd be gaming.
> 
> ...



even a cpu intensive game isnt going to heat up the cores like crunching would... would never run the risk of cpu throttling.  TjMax is 95C i believe?  1.45 seems about right however i personally wouldnt go over 1.370 just for paranoia sake.  ive owned a few e8500's and never had any problems with them running at those volts.  

instead of aiming for 4ghz why not 4.2ghz as long as the temps are reasonable?


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## Deleted member 24505 (Mar 23, 2010)

Sasqui said:


> What are you hitting for a FSB?
> 
> I've had my E8600 over 5 Ghz, gotta love that 10x multiplier



Gotta agree E8600 at 4ghz/400x10 here with 1.2vcore.Loving it.

Tjmax is 100c on E85/600 cpu's i believe.


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## qubit (Mar 23, 2010)

tigger said:


> Gotta agree E8600 at 4ghz/400x10 here with 1.2vcore.Loving it.
> 
> Tjmax is 100c on E85/600 cpu's i believe.



If I can get my E8500 to 4.11GHz 24/7 easily, I reckon you can do the same or better without too much effort.  It'll do 4.2, 4.3 or so without too much heat, but it's not quite stable after a while and I can't be bothered to spend the hours finetuning the parameters to stabilise it for this tiny gain.


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## Sasqui (Mar 23, 2010)

tigger said:


> Gotta agree E8600 at 4ghz/400x10 here with 1.2vcore.Loving it.
> 
> Tjmax is 100c on E85/600 cpu's i believe.



Isn't the math so much easier too? 

I think the max I've had my chip at is 1.4v - and only under water - and not for long.

Mine is Linpack/Prime stable at stock volts 4.3Ghz on air.  Nice piece of silicon.


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## BarbaricSoul (Mar 23, 2010)

according to intel, the e8400 shouldnt be ran over 1.36 volts



> sSpec Number: SLAPL
> CPU Speed: 3 GHz
> PCG: 06
> Bus Speed: 1333 MHz
> ...



http://processorfinder.intel.com/details.aspx?sSpec=SLAPL

I ran the E8400 I had for over a year at 3.83GHz@ 1.36volts with no problems.


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## Deleted member 24505 (Mar 23, 2010)

Mines about 1.3v for 4.5ghz,but tbh i am happy at 4ghz/1.2v.


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## trickson (Mar 23, 2010)

Hmm. My Quad is happy @ 1.4Vcore But also at 4.3 GHz ( just upped it again ) .


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## hat (Mar 23, 2010)

My AII 240 needs 1.4v for 3.5GHz


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## aCeFr3aK (Mar 23, 2010)

MatTheCat said:


> Having upgraded my gfx card from a 4870 to a 5850, I heeded someones advice (on this forum, I forget who), to push my E8400 CPU up to 4GHz (from 3.85GHz).
> 
> However, to attain this I had to push my vCore (CPU coltage) up from 1.306v, to 1.35v. Quite a few step ups in voltage increments to acheive an extra 150MHz on the clock. Furthermore, the benchmarks I am using (Heaven and 3dMark06) are indicating that I am not getting particulary overly fantastic performance improvements for putting all these extra volts through my CPU.
> 
> Please could someone explain to me why it is beneficial to have an E8400 running at 4GHz over say 3.85GHz or even 3.6GHz? Like I say, I decided in the past that 4GHz wasn't worth it but someone on here said that because I was getting a 5850, that I should push CPU to 4GHz



You sold the 4870? or are you keeping it.  I have one and idk if i should snag another for cheap and put them into crossfire or just hold out till i can afford newer stuff past the 5xxx series.


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## MatTheCat (Mar 23, 2010)

aCeFr3aK said:


> You sold the 4870? or are you keeping it.  I have one and idk if i should snag another for cheap and put them into crossfire or just hold out till i can afford newer stuff past the 5xxx series.



In the process of selling it for £70.....got an interested customer.


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## Jamborhgini313 (Mar 23, 2010)

I had my old e8400 c0 stepping at 4.1ghz at 1.36volts for 1 year before I upgraded to i7. I say go for it only if you can keep the temps below 80 full load.


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## 3volvedcombat (Mar 23, 2010)

In my opinion it would be good to keep it at 4.0Ghz 24/7

Reasons why?
* At the voltage of 1.35 you stay below intel specifics and at least 80% chance that your processor will last till 2012 if not 14-15
* You have a huge video card now, thats probably gettting bottle necked with 2 cores and 3.8Ghz on old architecture. Having that extra 200 Mhz lets back on the backround processes and should give you way more of a increase sense your not unlocking the full headroom of the video card with a 3.8Ghz 24/7
*In 2 years you'll be able to purchase something faster for less then 100 dollars, and can to this day i belive(Core i3's specifically)
*In a future view this would be the best for your whole gaming experience and should benefit doing 4.0Ghz.


Its your choice though.

But if it was my computer, your in the position to go FULL BLOWN on the processor and not really suffer any problems down the line. If it blows by 2012 or before it, then you can buy a whole new setup that will be faster on pennys on the dollar. If you dont have it at 4.0Ghz some games are going to suffer and in the next 2 years we can expect some cpu heavy games that are ganna need every MHZ they get including crappy ports that are showing up.

The perfect place to be in right now is to have a quad and some dx11 for future gaming.

The processor shouldnt even blow at 1.35 volts ever before it becomes way to undertech.


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## LagunaX (Mar 23, 2010)

Do a gaming benchmark with minimum/average/max FPS results at your current 4ghz setting and 3.85ghz setting.
Do Everest memory bandwidth test too.

Try to get 7.5 x 534 (1:1 on ram @ 5-5-5-15 or 5-4-4-12 if your ram will do it)  stable (also 4ghz).

Report back with some numbers =).


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## MatTheCat (Mar 24, 2010)

Jamborhgini313 said:


> I had my old e8400 c0 stepping at 4.1ghz at 1.36volts for 1 year before I upgraded to i7. I say go for it only if you can keep the temps below 80 full load.



Below 80!?! (u mean Fahrenheit?)

I gave up on my 4GHz already. Was getting crashes to desktop that I dont normally get and setting it back to 3.85 seems to have done the job.



3volvedcombat said:


> In my opinion it would be good to keep it at 4.0Ghz 24/7
> 
> Reasons why?
> * At the voltage of 1.35 you stay below intel specifics and at least 80% chance that your processor will last till 2012 if not 14-15
> ...



See thats the the thing, I never noticed any benefits at all apart from an extra 200 points for CPU score in 3DMark 06...but games...pffft...

At the moment, I am getting fantastic performance in games with my 5850 and e8400 @3.85. As for the quad core, my mates got an I7@4GHz and although he only runs a 5770, The performance he gets really isn't all that fantastic. In short, I get better performance on my rig with the E8400 dual core and the higher grade gfx card.


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## MatTheCat (Mar 24, 2010)

LagunaX said:


> Do a gaming benchmark with minimum/average/max FPS results at your current 4ghz setting and 3.85ghz setting.
> Do Everest memory bandwidth test too.
> 
> Try to get 7.5 x 534 (1:1 on ram @ 5-5-5-15 or 5-4-4-12 if your ram will do it)  stable (also 4ghz).
> ...



I underclock my RAM to 425MHz in order that I can lower the timings to 4-4-4-12. I found way back that this gave me just as good performance as 500+ MHz running at 5-5-5-15. So to get my 4GHz o/c, I raised RAM from 425 to 445, and raised vCore from 1.31 to 1.35 (multiplier sits at 9).


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## LagunaX (Mar 24, 2010)

Simple answer enough.
Download and run the Stalker Call of Priyapat benchmark.
http://downloads.guru3d.com/S.T.A.L.K.E.R-Call-of-Pripyat-benchmark-download-2433.html
Compare your min/average/max FPS under both settings.
However I think you'll get your best scores for frames per second (min/av/max) with 5-5-5-15 and higher fsb, especially 8 x 500 or 7.5 x 534. But with your ram you can probably do 5-4-4-12.


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## MatTheCat (Mar 24, 2010)

LagunaX said:


> Simple answer enough.
> Download and run the Stalker Call of Priyapat benchmark.
> http://downloads.guru3d.com/S.T.A.L.K.E.R-Call-of-Pripyat-benchmark-download-2433.html
> Compare your min/average/max FPS under both settings.
> However I think you'll get your best scores for frames per second (min/av/max) with 5-5-5-15 and higher fsb, especially 8 x 500 or 7.5 x 534. But with your ram you can probably do 5-4-4-12.



Will give it a pop m8!


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## InnocentCriminal (Mar 24, 2010)

Really what I would do is bench the games that you play and see if the performance, temps & voltage differences are actually worth it and within your safety criteria. Benchmarks are fun to see improvements but they don't _really_ give you a true representation of how your rig handles _your_ games.

I was aiming for 4GHz and couldn't get it Windows stable, the differences in volts between 3.4GHz (which is stock volts) and 4GHz were stupid so I'm staying at 3.4GHz, I may punch it back up to 3.8GHz at a later date.


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## Mussels (Mar 24, 2010)

3.85 to 4.0 will give you minimal boosts, i mean you're only getting a 4% boost in clocks - even if you were perfectly limited by your CPU, 4% wont make much difference - especially if you gotta loosen ram timings to do it.


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## MatTheCat (Mar 24, 2010)

Yup..I am staying at 3.85.

It has sat at this overclock for the past 2 years with no problems whatsoever. An extra 200 points on my CPU score in 3dMark aint exactly tempting me to cump it up to 4GHz.


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## LagunaX (Mar 24, 2010)

Nuthin wrong with 3.85.
I understand your lower timing thing - I used to do that with one of my older Asus builds.
But it did seem a lot snappier when I overclocked the ram at a higher fsb, cpu:ram 5:6 ratio.


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## newtekie1 (Mar 24, 2010)

I don't think even going from 3.6GHz to 4.0GHz is going to make a difference in real world gaming, benchmarking for sure, but definitely not in real games.


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## Mussels (Mar 25, 2010)

newtekie1 said:


> I don't think even going from 3.6GHz to 4.0GHz is going to make a difference in real world gaming, benchmarking for sure, but definitely not in real games.



thats why i'm sitting at 3.8, nice and cool - yet fast 'n happy.


to get to 4.2Ghz (where i see minimal gains) theres just too much extra heat for little benefit.


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## Goodman (Mar 25, 2010)

hat said:


> My AII 240 needs 1.4v for 3.5GHz



So?? 1.425v is stock voltage for AthlonII 240 

i got mine stable at 3.6GHz on stock voltage & 3.8GHz @ 1.5v temp never go higher then 43-44c in full (good air cooling with heat pipes) i can do 4.125GHz @1.550v 
It's a really nice little dual core & fast


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## hat (Mar 25, 2010)

I wonder if going from 3.5GHz to 3.8GHz is worth it? I wonder, is it worth the bump in voltage? I got a shitty 95w board, I'm afraid it might fry.


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## Goodman (Mar 25, 2010)

hat said:


> I wonder if going from 3.5GHz to 3.8GHz is worth it? I wonder, is it worth the bump in voltage? I got a shitty 95w board, I'm afraid it might fry.



I see your problem... i guess you'll be stock @3.5GHz with this board 

Anyhow 3.5GHz is fast enough even for gaming with a good graphic card


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## hat (Mar 25, 2010)

With the forumla in my sig, tdp comes out to be about 97w


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## D007 (Mar 25, 2010)

Yep, the difference will be very nominal.
Barely noticeable.
But none the less existent.

Although the higher you push a cpu, the more likely it is you can run into stability problems.
and the fact that your vcore voltage needs such a high push for such a small gain.
Says it's reached it's safe comfort limit.

You'll get a few fps in games that are more reliant of the cpu.
Like supreme commander and things that use lot's of ai.
But in general dx 9-10 and 11 use the graphics card as much as possible.
Dx8, now uses the crap out of your cpu.
but how much do u see dx8? lol..

the .15 gain isn't big.
but the vcore is not even close to dangerous.
Me, I'd keep it..lol.
cause I'll take every single frame I can get.
Not like your pushing 1.4 or 1.5v..
your plenty safe with decent cooling.


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