I've done a bit of research but I can't say I know a lot about overclocking but I was wondering how much I can get out of it without sacrificing the life of the CPU. I'm a little nervous even just touching the BIOS because I don't want to mess up my computer, but I was wondering what this rig can do and with a little help pull an overclock. I've never overclocked but so I wouldn't know what is right and what is wrong :S.

 

My rig is the 3820 @ 3.6 , 16GB RAM, GTX 660. I run flight sim at stable 30FPS (15-25FPS in VC) using PMDG747 in ORBX PNW with modest scenery sliders.

 

How much can I expect with an overclock? I don't have an after-market cooler and I'm really not sure what to pick. I'm not planning on OCing right away but I'm just trying to gather as much information .

 

Andrew

Because the i7-3820 has a semi-locked multiplier, it's "upper reaches" overclocking method is a tad different than the "K" or "X" chips. The motherboard's(your's?) capability plays a big role.

The i7-3820 does not come from Intel with a cooler, so, the one you have is aftermarket.

 

We'll stick with a Multiplier OC for now Using the standard 100MHz Base clock, 100MHz Strap, and a multiplier of 42, a 4.2GHz OC is relatively easy, and should be safely achievable with your cooler.

Start low, like 100clock x 40multi(4GHz), and stress test it while monitoring your temps. Increase the multi x1, and test it again. Small Vcore increases(one increment at a time) may be necessary for stability.

Use only the Vcore increase that allows full stability at 100% load. Pretty much anything under 1.4v should be OK as long as temp remains in check.

 

HyperThreading "On" can hinder stability at speed and FSX really can't utilize it, so, I recommend turning it off. Unless your other apps can utilize more than four threads and are that important to you.

 

I'm adventurous, so, my stressed temperature max is around 85C+. I've been cranking Intel CPUs up for a long time and have never had one fail as long as the fully stressed temps remain 10-15C under Tj max.

Other's limits are 75, 80C. Some prefer using a hard running temp of 60-65C max. Personal choice.

 

Stress testing while monitoring temps, Vcore, and actual speed is necessary.

You want a real time temperature monitor like Core Temp or Real Temp I use both.

CPUz(CPUID) will monitor the OC and provide actual real time Vcore and resulting RAM speed.

Stress test your OC steps using 10-20 passes of LinX, until you are happy, temps get too high, or the OC isn't stable at higher voltage.

Prime 95 32bit OS, or, Prime 95 64bit OS overnight should verify a 24/7 overclock.

 

If you get 4.2GHz and your temps and voltage are nice and low, report back, and maybe you can venture higher using the 125MHz Strap.

Let us know what your lowest available Multiplier is. Mine is 36 and using the 125x strap won't give less than 4.5GHz...Don

 

How much can I expect with an overclock?

 

 

Depends on motherboard and cooler.

 

I run the i7-3820 at conservative 4662MHz (37 x 126MHz) 100% stable on Prime95 (64-bit, last version, optimized for Intel's new AVX instruction set). ASUS P9X79 Deluxe motherboard and Corsair H80i liquid cooler.

My motherboard is an ASUS P9X79LE and the cooler doesn't look as extreme (looks pretty normal- one fan, and a metal piece) as some coolers I've seen... I'm not sure if I'll overclock just yet, but I'll definitely keep you posted if I do. Thanks, always good to know more!

Do not be afraid to mess up your PC. As long as you don't run too hot you've got nothing to worry about. A safe threshold is 75C for max core temp. Another thing is your CPU core voltage or VCore. Just like a car needs more fuel to the engine to generate more power, a CPU needs more voltage to run faster, therefore you've got to increase the voltage to a certain value. What value that exactly is, is almost impossible to predict. With a modest overclock, 1.25V will suffice. With a more extreme overclock, you might need up to 1.40V. For voltage, 1.40V is the threshold which you should stay below if you want your CPU to last for 5 years or so without any signs of degredation. Finding the right values for your VCore requires trial and error - and a lot trial and error (especially error). Start low with your voltage (for example 1.25V), you would probably get a BSOD (Blue Screen Of Death) when stress testing, but this only means your CPU didn't have enough power and couldn't keep running so it decided it wants to shut down. Overclocking instalbility will not damage your computer at all. Then, slowly increase the voltage until your stress test starts to last longer. Eventually, you want to end up with 12 hours of continuous stress testing without having had a BSOD and the test passing without errors. Only then, your overclock is stable and rock-solid. For stress testing, use the program Prime95. As soon as you fire it up and select one of the options, it cranks your CPU load up to 100%. The reason for that is, is because idle overclocks usually won't fail that easily under instability. When putting load on it, that's when overclocks start failing, so that's why.

 

As I said, don't be afraid, as long as you keep at or below the thresholds of 75C and 1.40V, there is pretty much no way you're gonna damage anything.

 

With your CPU, I would try increasing the multiplier, but keep your hands of the base clock, this causes instability, just leave it on 100 MHz. For overclocking mode, I recommend X.M.P., this mode will automatically put your memory (RAM) into its optimum settings (timings and voltages).

 

Also when overclocking, ALWAYS disable spread spectrum.

 

For extra information, please visit some overclocking specialised forums or watch some tutorial on Youtube.

 

Good luck!

...With your CPU, I would try increasing the multiplier, but keep your hands of the base clock, this causes instability, just leave it on 100 MHz...

That will be fine if 4.3GHz is all you want. The i7-3820 is partially locked, allowing a maximum multiplier of 43. The X79's "Straps" allow a higher overclock and do not sacrifice stability.

 

For example: For the rig in my sig, my Strap is at 125, Clock also at 125, and multiplier at 40, for 5.0GHz. Yes, I am running big voltage(1.485v) and big time liquid cooling.

Big 360mm rad and 6 fans, push-pull. 60% fan DC is quiet and keeps temp in check.

 

When building it, and doing initial testing, I started with 4.75GHz(125 x 38) at 1.368v. It ran Prime95 overnight on a cheapo CM Hyper 212+, 77C peak.

I had to, just had to, go for 5GHz on that $25 cooler, with a second fan added. It got through 10 passes of LinX without failing, but, it took a lot more voltage than I wanted to use.

Bottom line? Keep your voltage and temps way down if durability is a concern. If performance is primary, crank 'em up. Within reason, that is...Don

 

 

What a nice little cooler that 212. Impressive temps for 5GHz + 1.5V man

 

Arjen, this is SB-E. The base clock stays at 100MHz but you can still tweak the CPU strap for a (sort of fake) BCLK overclock, so yeah, no need to worry about instability just because the Bus Speed readout in CPU-Z shows 125MHz. The BCLK is still running at 100MHz under the hood

Thanks for all the contributions! I've learned a lot more and I'll use this as my guide if I am going to overclock, but how much should I expect on an OC? How much FPS will 3.8Ghz (how much more FPS) give or 4-4.3Ghz? I'm a little cautious about the heat as well, last time my older computer just wouldn't turn on (which is why I got a new one ) and I suspect it's because of the heat O.O -- The thermal paste which I think is suppose to be a thick gel-like substance was hard and It was a Q6600 2.4Ghz (stock cooler I think). I'm just very cautious because If I was to overclock, I won't have spare money to buy a new computer :(, my lack of knowledge makes me a little 'hesitant'.

 

Add-ons I use:

PMDGs

ORBX PNW

 

Edit: My Power Supply is 600W -- is it enough if I was to OC?