# Q9550 Overclocking: C1 vs E0 stepping



## Phædrus241

I'm buying a new CPU and power supply in July, a Core 2 Quad Q9550 2.83GHz and a Corsair 850tx. I've heard that there are two stepping version of the Q9550, the C1 and E0, with the E0 being better for overclocking. Unfortunately, Newegg does not say which version is provides, and some people report getting the C1 stepping, while others report the E0, with no discernable pattern. I want to know if it's worth contacting Newegg about to see which version I get, and how much difference it would make to overclocking ability. If it's just a matter of .1GHz more, or 1/8th of a volt less, I don't really care, but if it will make a large difference I want to know what I'm getting before I buy.

Also, what max overclocked speed could I expect with both versions, with these specs?

MBD: ASUS P5Q Pro
CPU: Intel Core 2 Quad Q9550 2.83GHz
HS/F: Thermaltake V1 110mm
PSU: Corsair 850tx
RAM: OCZ Platinum 4GB (2x2GB) DDR2 1066
GPU: Sapphire Radeon HD4870

Thanks.


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## greenbrucelee

you might get some good results although beaware that not all CPUs are created equally some cpus of the same speed and make might overclock a lot some may not. You need to get the E0 stepping one if your going to be overclocking. I reckon if you do everything correctly you might be able to achieve 3.2 possibly a bit more. You will probably have to drop the ram frequency down though. Since your buying an Asus board see what it's auto overclocking feature gives you. My Asus rampage formula gave me 3.52 on extreme mode but I have upped it to 3.91. I did have it at 4 but due to ambient temps being high because the summer I had to drop it.


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## Phædrus241

Was that with the E0 or C1 stepping?


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## greenbrucelee

Phædrus2401 said:


> Was that with the E0 or C1 stepping?


I said E0. The E0 will give the best results.


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## Phædrus241

Ok, thanks. Is it worth contacting Newegg about, do you think? Or should I just go ahead and order it and take what I get?


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## greenbrucelee

Well if you want a Q9550 get the E0 stepping one, I always get my stuff from www.overclockers.co.uk they will give you advice but they will tell you what I have told you.

Just to point out that nothing really uses four cores unless you do some serious video edition or use virtualization software. I have core 2 duo E8400 and it overclocks big time, I get better bench marks than most quads but thats down to the hardware and three months it took me to review everything.


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## Phædrus241

Ok, I've reconsidered, and I'm thinking about the E8500. The E8600 is nice too, but way too expensive for the performance gain over the E8500. Is that a good choice?


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## greenbrucelee

you could say the same between the e8400 and e8500 it's only 0.15GHz or something and I know for a fact that the e8400 overclocks like a beast. Given the correct components.

I have mine at 3.91 at one stage I was running at 4.2GHz and this air cooled! I knocked it down to 3.91 from 4GHz because ambient temps go up as it's the summer.


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## linderman

as stated; the E0 is easier to overclock and uses less voltage when overclocking too

you can call newegg prior to ordering and they will ensure you get an E0


IMHO the E8500 is worth the extra few bucks over the E8400; jus tmakes things a squeak easier to hit 4.0 ghz; I like my E8600 but I cant jusify the price compared to the 8400 or 8500; mine was a whim decision


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## Phædrus241

Yeah, that's what I figured, so I'm getting the E8500. It runs faster stock than my current processor overclocked to the highest it can go without failing Prime95. Hopefully I can get it to 4.0-4.2GHz.

My purchase:
Intel Core 2 Duo E8500 3.16GHz
Corsair CMPSU-850tx
Western Digital Caviar 500GB (my 320GB is 3/4s full and I'm planning on trying out Fedora 11)
Antec 120mm Tricool fan

Anyway, thanks for the advice. Hopefully this build will last me a couple years--I don't plan on touching it after this upgrade for a while, except for maybe an add-on card or two or some minor tweaks.


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## greenbrucelee

you should be ok then, let us know what results you get. I would interested to see how the e8500 compares to the e8400


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## linderman

greenbrucelee said:


> you should be ok then, let us know what results you get. I would interested to see how the e8500 compares to the e8400




for an advanced overclocker; you will only see a diff ofg about 200-300mhz in capability ...........not even noticible

but in the hands of a moderate experienced overclocker; the E8500 is much easier to get to 4.0ghz & stable ............


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## Phædrus241

What would I want to do to get the most out of this CPU? My current OC involved just upping the FSB speed until the computer wouldn't boot, then upping my VCore until it would, then running Prime95 for a few hours to see if there were any problems, then repeating until I hit the ceiling and could run Prime95 overnight with no problems, then tweaking my RAM speed and voltage. I've heard of messing with northbridge speed and all this other stuff, but don't know much about it. Note, I haven't got the system together yet, and won't until next week, I'm out of town atm. Question: if I overclock the NB for whatever reason is it worth it to get an NB fan (like this one: http://www.newegg.com/Product/Product.aspx?Item=N82E16835116018) or is it probably pointless?


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## greenbrucelee

It would be advisable if you are going to overclock the northbridge to get a fan for it. you should really need to do this though.

Your first method should be followed again with this overclock.


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## linderman

greenbrucelee said:


> It would be advisable if you are going to overclock the northbridge to get a fan for it. you should really need to do this though.
> 
> Your first method should be followed again with this overclock.






agreed


IMHO you dont need to mess with any voltages other than a slight bump for cpu and ram / the increasing of the NB voltage is only needed by the extreme squeezing of overclocking; such extremes dont offer much other than food for the ego.

you will seen no benefit or performance gain from a cpu thats at 3.8 when compared to one overclocked to 4.2

the improvement has been realized by the time you hit 3.8


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## Phædrus241

Ok, good. Thanks for the advice.

I know that by overclocking you shorten the lifetime of your components, so if I won't notice any difference between 3.8GHz and 4.2GHz I'll stick with 3.8. I'm running my current CPU into the ground so I don't really care, but I want to have a long-lived, stable build on this new one. And if overclocking the northbridge won't give me any noticeable performance boost I won't bother with it.

One last question: should I change the multiplier at all? Looking at reviews of the E8500 overclocking, some people upped the multiplier to x9.5. Would this, in combination with increasing FSB frequency, give better OCed performance, or a better performance/voltage ratio, than increasing FSB alone?

Anyway, thanks once again. :grin:


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## linderman

the stock multiplier of the E8500 is 9.5 x 333= 3164 you cant raise it any higher as its locked

but instead you raise the Cpu host frequency (FSB number) 400 x 9.5 = 3800mhz

the E8500 will get to 4425 x 9.5 = 4038 mhz without much sweat, after that it gets more difficult ...... but I have personally got them to 4.2 but IMHO above 4.0 is stress city


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## greenbrucelee

some people lower their multipliers and increase the figure in the FSB to try and get more performance although I have never really seen the value of this. As Linderman says you won't notice any difference between 3.8 and 4GHz. When I use my Asus rampage auto overclock feature it put it at 3.52 at first I went to 3.7 absolutley no difference only when I got to 3.9 and 4GHz could I notice a difference. I have had it at 4.2 but the temps got a bit high for my likeing.


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## linderman

the E8500 does better on higher multipliers than it does underclocking


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