My E8400 overclocking project (need your help)

Hello everyone,

I must admit that I came here seeking answers that will help me succeed in my overclock project.

Last week, I purchased BF3 only to realize that my CPU was holding me back in servers containing over 30 players. Even playing at the lowest settings, my trusted Wolfdale (E8400 dual core @ 3.00GHz) quickly jammed at 100% load. Being the student that I am, I didn't want to invest money I frankly don't even have on a new motherboard + CPU.

My research up till now
I soon figured out that my best bet was to work on the CPU since it's the bottleneck part and what better way to do it than an OC? If done well, it's a cheap option that might work its magic in this particular case.

So I checked out a few posts of interest (google and youtube were indeed my friends) and decided I would go for a better CPU Fan before OCing. And so, in the last 4 days, I proceeded to switch my stock CPU fan for a CM Hyper N520.

After installing it upside down and having to take everything out on a 2nd try, I can finaly say that I made it.

Time to OC
Now I'm at the actual OCing part. I've seen a few videos and posts of people overclocking on the same CPU / Motheboard as I have but as they were going different routes, I decided it would be best to ask for advice here before taking any action.

Basically, I would like some pointers from seasoned Overclockers on the bios settings I will need to adjust.

In order to help out, here's a basic listing of my system parts along with images of my CPU-Z/SPEED FAN infos and finaly, images of my BIOS options.

My system
Intel Core 2 DUO E8400 @ 3.00GHz (C0 stepping)
ASUS P5K/EPU motheboard
2 X 2GB DDR2 800MHz (so that's 400MHz * 2 since DDR2)
CM Hyper N520 Fan
AMD Radeon HD 6850
600W ATX Seasonic SS600ET
Windows Vista 64x


Edit: Those temps are at idle and with the stock fan. System Temp is now at 46C and CPU Temp is at 31C with the new fan.


Final Word
I'd like to say thanks in advance to those who will help out as this is a delicate operation for someone who can't afford to blow anything up. Know that your time in helping is appreciated.
15 answers Last reply
More about e8400 overclocking project need help
  1. You're somewhat limited by your ram. The highest you can go is 3.6 without overclocking your ram. That will give your ram a 1:1 ratio with the FSB for 3.6ghz on the cpu.
    You might be able to go higher if you're willing to tweak your ram settings. That will add more time to your project as more testing and tweaking is necessary for overall system stability.

    Have you read any overclocking guides, and have a decent idea of what to do? First thing you should do is do some quick research and find safe temps and voltage for all your parts.

    There is also a core2 overclocking guide here stickied at the top of the forums. Questions are good, but you really should get an idea of what you're doing first.
  2. Hey Cygnus,

    Thx for the info. I did check a few guides out but they always seem conflictual. That's why I was reluctant to go ahead only with those and wanted to post my own experience and get the help I'd need down the road.

    You've already given me good pointers. Yes, the ram sucks but my motherboard only takes DDR2 and it would be too expensive to upgrade here.

    3.6 GHz might be okay, I will know once I get there and play some BF3 rounds. I'm looking for a good gaming experience on the lowest settings. As of now, the CPU can't handle multiplay on servers with a lot of ppl as for BF3.

    If 3.6 GHz ain't cutting it, I'll be looking to get close to 4.0 GHz. So yes, the memory and my C0 stepping might be preventing me from achieving a big overclock but I might just get to 4.0 GHz if done well.

    I'll start by looking into the guide you mentionned and then post which changes I would make in the BIOS. Maybe you guys will be able to prevent any mistakes before they actually happen.
  3. This is our generic Core2 OC guide. It is based on one of the Asus boards:
    Core2 Overclocking Guide

    Go through the guides. Then take your core voltage off Auto and set your memory voltage to factory recommended values. Change the System Memory Multiplier (or whatever your BIOS calls it) from AUTO to 2.00 - whatever you need to set the Memory Frequency to twice the FSB. Then when you increase the FSB, the memory clock will rise in in proportion with it. At an FSB freq of 333 MHz, your memory clock should be at 667 MHz.

    One time you may be able to do is stretch your RAM performance a little by relaxing the timings from 4-4-4-12 to 5's-15 or from 5's-15 to 6's-18 and increase RAM voltage to a max of 2.2 volts.

    Core2 systems are relatively unaffected by changes in memory parameters. I suspect that it's because of the relatively large L2 cache.

    Do not exceed 1.45 volts core voltage or 70 C load temps.
  4. Ok so I have pretty much followed the guide you listed by jsc (thx!) and brought my initial changes to the BIOS.

    My DDR2 800MHz was already timed at 5-5-5-18. While that seemed weird as opposed to what the guides say, I decided to leave it at AUTO as I did with VCORE.

    Now CPU-Z shows:

    Core Speed 3604.0 MHz
    Buss Speed 400.4 MHz
    Core Voltage: 1.272 V

    DRAM Frequency 400.4 MHz
    FSB:DRAM 1:1
    Timings 5-5-5-18
    Command Rate 2T (what is it?)
    DDR Voltage: 1.80V (manually set at stock setting)

    Idle temperatures
    System: 43C
    CPU: 31C
    Core 1: 40C (which one is important, CPU temp or Core Temp?)

    Load temperatures
    (to be determined)

    Anything suspicious? Will try to run some tests using PRIME95.

  5. Well now it's been 10-15 minutes that I've ran prime95 (blend test) and so my CPUs are under full load.

    Core temp = 55C to 59C so far

    This brings me to ask 2 questions:

    1) What's a reasonnably safe temparature limit for the cores under full load?
    2) Can I leave this running all night without sitting in front? Will Prime95 shut down if the temperatures go too high?

    Tks again
  6. Like I said earlier, 70 C is at the upper limit of "safe".
  7. Well I ran Prime95 for 8 straight hours and my core temp stayed between 50C and 58C, which is good in my mind.

    Also, I'd like to highlight that I left the VCORE on auto so it is likely that it has been automatically set too high if the proposed guide was correct.

    At this point, I will try running BF3 which is the reason for the OC and come back with the results.

  8. Ok, all is not perfect here.

    Took me 5 tries to get into a BF3 server. Each time, the screen would freeze right between game launch and entry of a server. The error message was BF3 detected a problem or something along those lines.

    On the 5th try, I managed to get in but after about 5 minutes of gameplay, the screen froze again with no error this time.

    What does it mean? Is it possible to torture-test my CPU with Prime95 for 9 straight hours without a single error and not failing in BF3?

    Thanks for the help, always appreciated.
  9. I have been prime stable and then crash in a game before. Prime95 isn't the know all end all of programs. It helps no doubt, but it isn't perfect. What are your setting now?
  10. You should have an option in the BIOS to save BIOS settings. Save your overclock settings so you can restore them later.

    Then restore factory defaults. Now try to enter a BF3 server.
  11. Thx for the tip jsc but before seing your post I reinstalled my GPU drivers and it did the trick. Weird, I had them installed a few days ago only.

    Cygnus, other than the settings post-OC I posted in a previous message in this thread, what would you like to know?

    With my current memory, I'm wondering how I would have to do to get from 3.6 GHz to 4.0 GHz. I have DDR2 800 MHz and my FSB is at 400 for a nice 1:1 ratio and if I understood correctly, I'd have to OC my memory to get it higher as it's not made to support higher than a FSB of 400?

    Also, my timings were already at 5-5-5-18 stock while I've read on numerous guides/posts that DDR2 800 MHz usually runs at 4-4-4-12. In my overclocking process I was confused about this and so I've left everything memory related on AUTO. Now CPU-Z still shows 5-5-5-18 with a command rate of 2T (what is the command rate again?)

    Thanks for helping me here.

  12. Definition of command rate:
    -Command Rate / Command per Clock (1T/2T).
    Delay between when a memory chip is selected and when the first active
    command can be issued. The factors that determine whether a memory
    subsystem can tolerate a 1T command rate are many, including the number
    of memory banks, the number of DIMMs present, and the quality of the DIMMs.

    Lower is better, but my experience indicates that you get little practical benefit going from 2T to 1T if your BIOS lets you.
  13. Great thanks for the detailed answer.

    Do you know if I can OC from 3.6 to 4.0 GHz without touching my memory settings? I think not but then again I'm still new at this.
  14. I had a E8400. And the highest O/C I could get stable was 3.8 GHZ. Anything after that wasn't stable. I recently upgraded to the i5 2500K. I hate to say, but the Dual core is just past it's prime for the new games!!!!
  15. patlav1980 said:

    Do you know if I can OC from 3.6 to 4.0 GHz without touching my memory settings?

    Don't know. A lot of E8400's will run reliably past 4 GHz.

    Try to push the FSB up past 440 MHz (maybe 10 MHz at a time).

    Maybe your memory will run past its specs. If not, try this:
    Increase RAM voltage to 2.2 volts (don't worry, it's safe).

    Relax the memory timings from 4-4-4-12 to 5-5-5-15 or from 5's-15 to 6's-18. That should give you room to run at the higher speed.

    Remember, if you have stable settings for 3.6 GHz, save the BIOS settings.
Ask a new question

Read More

Overclocking CPUs