What determines how far you can Overclock?

[Harudath]

This is a question I've been wondering about for a while, because my CPU used to be OC'd at 3.4GHz, then I lowered it to 3.2 for a test and now the highest I can go is 3.3... What can I change to overclock to higher speeds? chipset cooling? Better CPU cooling?

[Thrax]

1) Higher-end parts.
2) Luckier parts
3) Temps

[Snarkasm]

I was actually wondering something myself, despite my success at OCing; is the situation with most boards "as long as you have the cooling, all the parts can take all the voltage you can give them," and thus it's totally cooling-dependent, or do some parts have an inherent voltage limitation in which you could phase-change cool it to a constant -30C and you'd still fry something if you gave it enough voltage?

[Thrax]

No matter what cooling you slap on a part, there's a voltage you can use that would roast it.

[Snarkasm]

K, good deal.

[Leonardo]

Harudath, just to reiterate what's already been posted, but with different terminology:

+ PSU - high quality, plenty of amperage available to the 12v 'rails'
+ motherboard - high quality, BIOS designed for overclocking, good voltage regulation, good quality capacitors
+ RAM - high quality, 'headroom' to increase frequency beyond its specifications (if FSB overclocking, otherwise use motherboard 'dividers' to keep the RAM at close to rated speed)
+ heatsinks - northbridge and CPU that can dissipate excess heat created through increased voltage to those components
+ CPU - headroom for increasing speed - some have it and some don't, but there are trends
+ computer case + good ventilation and room to accommodate large CPU heatsinks
+ skill - getting all the voltage, ventilation, and cooling device variables lined up for optimum performance

[Harudath]

Thanks Leo, even I could understand that :P So, with good enough cooling (Motherboard, and RAM were designed in a way that makes Overclocking VERY easy) how far, do you think an E6750 could go? I've heard of people with 1.8GHz Core 2 Duos going all the way up to 4GHz, which is insane >.< I was hoping to push my 2.66GHz from 3.3 to as close to 4 as I can without frying the thing :P Idle temps are ~25 with stock cooling and the core voltage is 1.472.

[muddocktor]

I have an E6750 I'm running on a GA-P35-DS3L board with some Ballistix PC2-5300 ram and I've been able to push mine to a little over 3800 MHz with around 1.5v vcore. Getting to 3600 was pretty easy but after that it took steady vcore increases to get just a little more speed. That was fine to do for benching runs but I wouldn't keep my system at that speed for 24/7 use. I settled at 3600 MHz as my 24/7/365 running speed. Of course, your results could be much different than mine because your overclock all depends on the luck of the draw for your processor, mobo and ram and how well it deals with the extra speed. BTW, I was cooling with an XP90-C with a Delta 3 blade fan and it does pretty decent, but I could see it's effectiveness falling off towards the top end of my benching runs. I imagine that with an U-120X or good watercooling I could get a little more out of it.

BTW, what you you using for monitoring your temps, Core Temp? Your idle temps sound low for your present speed and vcore to me.

[Harudath]

Yup, CoreTemp

My Specs:
E6750
ASUS P5N-E Sli
Kingston HyperX DDR2 Overclocking RAM
Antec 900 and a truckload of cooling, except for the chispset and CPU cooling which is stock level.

My motherboard has a problem in that I'm limited to a heatsinc 10cm in diameter MAXMIMUM before it can't fit thanks to the northbridge- If anyone can reccomend any smaller NB heatsinc/fan combo then that would be fantastic :D

[muddocktor]

I have one of those boards myself, which is presently in RMA. :(

For a hsf, you should be able to mount a U-120X or U-120 on it with the stock nb cooler with no problems. The TT120 will fit too, but it's tight with one of the capacitors near the socket and the mounting bracket. I don't remember if I tried the XP90-C on it. When I get it back from RMA I can definitely check it for U-120 and XP90-C mounting though as I plan to take the XP90-C off my E6750 and run the U-120 on it and I can just wait until my P5N-E gets back from RMA to do the switch.

EDIT: I was still using the stock nb cooler but I did remove it and clean that factory tim off and reinstalled it with Ceramique. I also added an old cooler I had laying around to the sb too, which might help at high fsb speeds.

[Harudath]

I had a look at some heatsincs, and http://www.tekheads.co.uk/s/product?product=603481 caught my eye. Affordable, seems effective, fits... Waddya think?

[muddocktor]

Had one of those, wouldn't be a good choice both for the cooling part (I doubt it would be much more effective than the stock cooler) and for board clearance too. It's pretty big around and you might have capacitor clearance problems.

A better choice would be this one (http://www.tekheads.co.uk/s/product?product=605121), which was pretty highly rated in Anandtech's testing (http://www.anandtech.com/casecoolingpsus/showdoc.aspx?i=3210). I don't think you would have any clearance problems with it either.

EDIT: Here's the Newegg reviews page for the Freezer7 Pro if you want to read more on what people think of it also. Linky to Newegg reviews (http://www.newegg.com/Product/ProductReview.aspx?Item=N82E16835186134)

[Harudath]

Okay, I had a look round on every well-known european site I know for the u-120 series, and it found nothing :S

[mmonnin]

Your overclock is dependent on your pen0r size, true dat!

The cost to get to 3.5-3.6 on a C2D based CPU isnt all that much more than stock but going above and beyond that is where costs really start to add up. Usually it takes some bleeding edge equipment to get the bleeding edge speeds.

I find it more cost effective and better for folding if I dont care to push 1 machine to its complete max by buying the best because I could spend quite a bit less on motherboards, RAM, motherboards w/o the frills, etc and buy another system. Plus going to the extreme it takes more electricity and heats the apt in the summer...

Try to find of these for cooling if it'll fit:
http://www.anandtech.com/casecoolingpsus/showdoc.aspx?i=3210

[Harudath]

I wouldn't mind 3.6, 3.8 would be awesome. One thing I was worried about though, does a tall, heavy heatsinc stress the motherboard much? I've heard that they damage/wear out the motherboard quite fast.

[muddocktor]

Heh, beat you to it, Marc. ;D;D

I even linked him to one there at the store he had found the Zalman at.

BTW, that Ballistix you guys makes kicks ass. I've had that cheapo PC2-5300 Ballstix up to 560+ MHz at 5-5-5-15 2T timings at 2.1v in my E6750 rig. :thumbsup:

[muddocktor]

Harudath, I wouldn't worry about it breaking the mobo if you are careful with mounting and removing it and don't carry your board by the heatsink. :)

[Harudath]

Okay :P I've just heard rumours that this can happen, so wanted to make sure this myth was busted without having to ask a TV-show to do it for me :D

[mmonnin]

Hehe oops. I usually pick up the motherboard by the HS to install it. At least I used that with the older Thermalright SLKs. I figured its the heaviest part of the HS/CPU/motherboard combo.

As long as you attach it correctly the weight will be spread out across the board enough with all the screws in the mounting holes.

Thats a nice OC for that part. It sure was conservatively binned out. I'm looking forward to the next gen DDR2 we will be producing in the future with a (much) smaller feature size.

[Harudath]

I've got my sights set on the http://www.tekheads.co.uk/s/product?product=605121 but the reviews seem to indicate otherwise... 3 stars out of 13 ratings, although the stats on that review look extremely tempting...

[Snarkasm]

Yeah, I would have said the opposite. I'd much rather pick up a mobo by the heatsink than grab it by the edge of the board and let my Infinity flex it all over the place. ;)

[Harudath]

Ah, okay :D

[mmonnin]

Yeah especially HSs that fit into the stock AMD/Intel HS contraption, they arent going anywhere and are seated firmly to the motherboard. Plus I would rather pick it up by the HS than by about anything else on the motherboard. HSs, PCI connectors, or rear panel connectors are about all I use beside the edge of the motherboard. But then I bet I am rougher on my PC parts that most other people, I've had at least 1 computer sitting on my desk w/o a case for about 4-5 years now. :D

[Harudath]

Hehe :D So it's a definate yes to the Arctic Freezer 7 pro then? :D

[muddocktor]

I see nothing wrong with the freezer7 Pro except that I don't like the pushpin mounting method. I rather a hsf that uses a backplate instead, but the pushpin mounts are what Intel uses for their retail heatsinks. If you are using a heatsink that uses a backplate to mount it then I have no problems with picking up a mobo by the installed heatsink but I think that if you pick up a mobo by the heatsink that mounts with the pushpins, you are stress loading the board around those 4 holes way too much (point loading a very small area around the mounting holes). With a backplate, it spreads the load over a much wider area of the mobo. But as far as mounting purposes go, the pushpin method is satisfactory.

[Harudath]

That's cool- I don't intend on moving my mobo enough to want to get a heatsinc purely to grab it :P Besides, my NB hs is huge, so I can always pick iy up by that/the edges like I usually do :P

Thanks for the help all