Help newb hit 4GHZ (E8400 P45)

[MN12BIRD]

Hey guys. I must admit I know my way around computers pretty well but never really took big on the whole overclocking thing. Just for fun I did 3.6GHZ on stock voltage and it was fine. But I know I'll need more settings to get to 4GHZ!

Intel E8400
Gigabyte EP45-DS3L motherboard
OCZ 2x2GB DDR2-800 Gold at stock clock/timings
OCZ 600W PSU
Radeon 4870

I also have an OCZ Vanquisher or something. I forget the name exactly but it's a 90mm tower with 3 copper heat pipes. It's nothing special but dropped 10 degrees from the stock Intel cooler under load. I think it would handle 4.0 just fine.

So I understand the FSB, but I have a few questions. Do I have to change the RAM clocks if I change the FSB past a certain point? I would like to keep it as simple as possible to start so if I can do this without changing RAM settings that would be nice. I know I have to bump voltage but I'm not sure what is safe and what's not. Should I use the stock multiplier or try lower?

FSB?
Multiplier?
CoreV?

I might OC the video card a bit but I already have done all that before so no issues there.

Any tips or pointers from fellow P45/E8400 owners would be great!

Thanks

 

[angelkiller]

Ok, I don't have a P45/E8400 anymore, but I did have them at one point.

You want 450MHz*9 @ 1.3v. That should get you 4.0GHz stable.

Just make sure the memory frequency is around 900Mhz. If it wayy off from 900, you'll have to play with a setting or two. But you may not. Try what I said above and let us know what happens.

 

[MN12BIRD]

Okay thanks I'll try that for now and see how it goes!

 

[MN12BIRD]

Great! It's been running at 4GHZ for an hour now. I ran a few benchmarks and so far so good.

My RAM is at 900MHZ like you recommended with the stock timings. I have to admit this is easier than I thought! I mean I heard it was easy... but THIS easy? Hahaha to 4.0GHZ anyway! I had it in my head that even at 4.0GHZ I would be needing to tweak much more.

Now really how safe is an 1,800MHZ FSB on my board? I mean considering the P45 is only unofficially rated for 1,600MHZ right? Well 1,333MHZ if you ask Intel right

 

[erocker]

1800mhz should be fine. What are all your temperatures like?

 

[angelkiller]

erocker is right. A 450MHz FSB is only 12.5% out of 'official' spec. But to be quite honest, you'll reach speeds where your board or CPU can't physically run before you reach speeds that are unsafe to run. You're fine. I guarantee Gigabyte engineered the board to support FSBs much higher than 450MHz.

 

[MN12BIRD]

Well when doing gaming benchmarks CPU temp is 47°C in Speed Fan and Gigabyte ET6. Not sure where NB temp is shown. The only other temp in ET6 besides CPU is "System 1" is this NB temp? If so it was also ~45°C.

Problem. Although it hasn't crashed in any benchmarks or crashed the OS yet, Prime 95 is crashing within 2 minutes. It doesn't take out the OS, simply shuts down P95. CPU 2 minutes into P95 was still only 50°C.

 

[angelkiller]

Temps look great!

Because it fails Prime means that it's 100% stable. But because there haven't been any BSODs or random freezes, it means we're close to stable.

I would up the voltage a bit. Maybe try 1.35v and see what happens to temps and in Prime 95.

 

[MN12BIRD]

Well that seems to have done it. I bumped the voltage up to 1.35v and P95 didn't crash within 2 minutes like it did the first 2 times. I only let it go for 15 minutes but my CPU temp was hanging at 60°C

I'll let it run for a longer period of time when I have the time. What would you guys recommend for a good test time?

I'm surprised how .05v can make such a difference in temps! But hey 60°C is still acceptable! I mean shit I think I hit that at 3GHZ on that little stock Intel cooler!

Just out of curiosity when would NB voltage tweaks be necessary?

 

[angelkiller]

Great, I'm glad it worked.

As you have just seen, changing the voltage has dramatic effects on power consumption. I think there's a squared relationship... I'm forgetting the exact formula.

I think NB tweaks are necessary when you start dealing with really high FSB values. (eg 500MHz+) Then the NB needs more juice to keep everything flowing at those speeds.