Can't overclock intel core 2 duo E8500 3.16GHZ while it's already unlocked; help ASAP

First, make sure the Intel EIST is disabled as well as C2/C2E Support.

You also want to turn the PCI Express Frequency off of Auto and to 100 for starters. You don't want to OC the PCIe Bridge.

It doesn't help that you are mixing RAM modules, but when you OC, make sure to change the "System Memory Multiplier" to whatever maintains the stock speed of the RAM. If you want to OC the RAM, do it after you get the CPU stable, then if you want to OC both further, you will at least know what the stable OC is with RAM at stock.

For now, set the voltage to 1.24v, if not there leave at 1.2....for now.

These are things I had to do to get a stable OC of a Q8400 up to a 3.2ghz. However on a different motherboard.

When you change the CPU multiplier the RAM sometimes OC's automatically. That's why I mention it.

Did you change the PCIe setting?

Maybe try backing down the OC from 4ghz, maybe to about 3.4 or 3.6 and work up from there. Have to remember that not all CPUs are equal and it's possible your CPU can't get to 4ghz. That or the motherboard isn't capable, I've seen a couple threads on other sites stating that this board isn't very good for OCing.

So we are on the same page...stock is 3.16, you want to OC to 4ghz and 1.3v because you saw somewhere online that those settings are where it can easily be, or because the motherboard has the settings available.

What I am suggesting is to try smaller overclocks with less voltage to see where you can get it...with PCIe set to 100mhz, not auto. IMO, either the CPU, motherboard or another setting is not capable if running the CPU at 4ghz and/or 1.3v. Just because some people or even many people were able to use those settings does not mean you will too. That's why it's referred to as the silicon lottery. I'm thinking that the motherboard, even though it offers the voltage setting, likely is the weak link here. But you may be able to a decent OC with what you have.

TLDR; Start with a smaller OC and work your way up, instead of just going straight for 4ghz. The problem isn't necessarily that the 1.3v isn't staying, it's that the settings are not compatible with your hardware so it resets to a working configuration that lets you back into the BIOS.

I am not sure about your RAM, you will have to give us the specifications, speed and timings [latency] - or at least a part number. RAM type has an impact on overclocking.
Your motherboard is not the best for overclocking. And, your power supply is not one I would pick for overclocking.

You have several problems with your current computer build for overclocking and any one of which can cause you not to reach 4GHz, even if your CPU is good enough to reach it, which I do not know if it will.

I have a Gigabyte P35-DS3R and it has at least 11 mosfits, and yours has only 6 - total. I also have an Intel E8600 that overclocked to 4 GHz without breaking a sweat. I have an aftermarket cooler, however, I cannot remember which one it is, too many years have past and my memory is not that good.

I still have the computer, however I put an Intel Extreme $1,000 CPU in it after the price dropped to about $260 dollars. My E8600 is now in the original Intel retail box, fan and all, sitting on a shelf. I never used the stock Intel fan because I overclocked the E8600 from day one.

There are a few tricks to overclocking, however, there are no guarantees, as Martell1977 said. Try taking out one stick [leaving one stick] of RAM and unhook anything not needed to run the computer to ease power requirements on the power supply and motherboard circuitry. Run the CPU at stock speed and lower RAM voltage a little at a time until it becomes slightly unstable then increase the RAM voltage .01 volt to regain stability. - RAM voltage affects overclocking because of the extra load on the circuitry on the motherboard, which yours is very susceptible to stress.

With the above in mind, increase the CPU voltage [Vcore] to 1.365 [or as close to that as you can get]. Next, begin to overclock 100MHz at a time, for example 3.16 to 3.26 [or the closest you can get to it], then continue to up the CPU frequency 100 MHz at a time until it is unstable. Keep an eye on temperatures with HWiNFO I list below.

For a fast stability check download and install CPUID CPU-Z and HWiNFO64 [or 32 if your operating system is 32 bit]. After getting to the windows screen open both programs. Keep bumping up the CPU frequency and every time enter Windows and try to open those 2 programs. Once you enter Windows but cannot open those programs, reboot and enter BIOS and reduce the Vcore .015 volts and stress test it.

Before stressing your CPU open - and keep open, CPUID CPU-Z If you do not have a good stress program you can download Sisoftware Sandra Lite [free version] and run the Arithmetic burn-in, do this by running the program, click on the Tools tab at the top, in the drop down list select Burn-In. At the bottom you will see a purple arrow pointing to the right, clicking this will take you through several pages. De-select everything but the first option, Processor Arithmetic. Next, select run 3 times. Next set Minimum Utilization to 100%. Next, set Board Temperature to 85, CPU Temp to 95 and CPU 2/Aux Temperature to 95. Keep clicking the [right pointing] purple arrow, click save file on disk, next select Text Format (.txt) to save a report, Next page give your burn-in a name. Now, at the bottom you will see a purple checkmark, click on it to start the test. You will not have control of your computer because the CPU will be fully used by Sisoftware Sandra.

If your computer passes the burn-in tests enter BIOS and begin reducing the CPU Vcore .005 volts at a time, entering Windows each time and try to open CPUID CPU-Z and HWiNFO. Keep lowing the Vcore until you can enter Windows and cannot open CPUID CPU-Z and HWiNFO, then enter BIOS and increase Vcore .015 volts and run SiSoftware Sandra Burn-in again [it will remember your previous settins, though you may need to click on the right facing purple arrow at the bottom to get through all pages.

Keep HWiNFO open while benchmarking so you can keep an eye on CPU temperatures.

If you fail the Burn-Ins, reduce the CPU Vcore a little or increase RAM voltage a little at a time until you are stable. Once stable put the rest of the RAM in the motherboard and check for stability again, increase RAM or CPU Vcore a little until your overclock is stable.

Post here what you find out.

If you want decent overclocking, you will want to look for a board with Intel's X48 or P45 chipset. Just make sure the board supports DDR3 as well.

The ASUS you listed seems to be regarded as a limited overclocking board and doesn't have much in voltage control.

Martell1977 is giving you some good advice. One of your problems may be, I am not sure, that you are not visualizing some of what we say, especially the long post I made.

In my previous post I forgot to tell you, after finding the fastest stable CPU overclock, begin slowly lowering the RAM voltage until the computer becomes unstable, then increase RAM voltage .010 volts and run another test, this time for the CPU and RAM, both can be done with SiSoftware Sandra.

Here are a couple of videos. The first person has music turned up too loud and is distracting. The second video is using an Intel motherboard, however, the "expert" gives some good, though nebulous suggestions because he does not get specific, such as a great power supply or RAM to use for overclocking, however, it may provide a little help in your thought process.

https://www.youtube.com/watch?v=ID5jrxAV9SU
https://www.youtube.com/watch?v=LlhlUHIOMTM

It depends on how much you want to spend and if you mind waiting for shipping. There are some options on eBay, but most are international and cost around $80. http://www.ebay.com/sch/Motherboards/1244/i.html?_sop=15&_nkw=p45%20motherboard&_dcat=1244&Socket%2520Type=LGA%2520775%252FSocket%2520T&rt=nc&_trksid=p2045573.m1684

Just chekc the list to make sure it says DDR3 and you can reuse your RAM. there are more options should you want to change to DDR2, but there is a performance difference that may be noticeable as DDR2 is much slower.

This might be a little late in the game to be asking but what multiplier and FSB did you use to get 4.0GHz in your initial scenario? Achieving a 4.0GHz overclock at 667x6 would not be the same as one achieved at 421x9.5. The multiplier will only affect the CPU frequency, but the FSB will affect everything else, including your ram. If it was something crazy like 667 FSB @ 6x multiplier, it would make sense that it won't boot.

First off, I would recommend "under-clocking" the ram such that is close to a 1:1 ratio for FSB : DRAM, that way you don't overclock the ram unintentionally outside of manufacturer specs as you increase the FSB frequency. You can do this by adjusting the multiplier and making sure that the resulting frequency is not outside of the labeled specs on the ram.

Second, as Martell1977 and Danra have said previously, try to do incremental increases to your overclock, instead of a huge leap from 3.16GHz to a sudden 4.0GHz. It would help isolate certain issues and problems that might be causing your instabilities.

I break my stability tests down to two parts; one is to test for instability due to CPU the other is for NB and ram. I would usually run prime95 in smallFFTs with CPUz, speedfan, and coretemp opened up to check for the utilization, temps, and voltage changes. Any sort of error or BSOD usually points to insufficient Vcore. Errors in Memtest would tell me that I need to do something about NB strap, NB voltage, ram voltage, or ram timings. Of course, I usually don't mess with ram timings and voltages, so that only leaves me with NB strap and voltage to deal with.

Also, I wouldn't recommend going out of your way to buy a new motherboard either, much less to be willing to pay 80$ for a second hand one off Ebay. The E8500s have been known to work great at low voltages, many have had them running at 4.0GHz at close to or a little over 1.20V. The E8500 build I have is currently running at 3.6GHz @ 1.216V and I think THAT is already too much voltage. This was also done on an old GA-G31M-ES2L MB that I found for less than 10$ on Cragslist

First, it is absolutely possible to overclock just the cpu alone and even under-clock the ram.

Second, easy energy saver technology only kicks in if you have installed and run Gigabyte's Easy Energy Saver software.

Third, you do not need to increase Vcore unless prime95 shows you errors or BSOD. If you are taking small steps in overclocking, you will first encounter errors in prime95 and a single core running at 0% instead of 100% when your cpu begins to not get enough voltage. Beyond this point, your pc will flat out BSOD within the first 30mins of stress testing.

It was a good idea to not fiddle with ram settings, but you DO NEED to adjust the memory multiplier. Assuming your ram is fairly standard, you will want to keep the memory frequency at, or below, 1333MHz. Tweak your memory multiplier to match that, and you should be fine most of the time for ram. Though in rare occasions, some overclocks have been found to be more stable when the ram is under-clocked.

Now, you will need to run Memtest to determine if there are any issues with the memory or Northbridge. Download Memtest and make a bootable USB flash drive to run it. A single pass on Memtest should be enough to tell you if you have any issues or errors. If your ram is running at or below 1333MHz like I mentioned but Memtest discovers errors, it is possible that you need to up the Northbridge voltage by one increment. Though that is fairly unlikely, as I have only ever need to do so after the FSB is at least above 400 on a E8500.

An overclocked cpu should not show any loss in performance, unless it is unstable and riddled with errors.

Just for reference, my E8500 is overclocked to 3.7GHz (9.5x multiplier & 390 FSB), Vcore set to 1.250V (with the voltage dropping to 1.200V at max load due to Vdroop), DDR2 running at 2.0V and 936MHz (a 2.4x multiplier), NB voltage set to "normal". This was all done on my aforementioned cheapo motherboard.

It would also be easier for us to help if you can provide a bit more detailed information about the exact settings you have set in your bios, such as the cpu multiplier, fsb frequency, memory multiplier, memory frequency, & whatever else you might have changed from default settings.

Take the RAM OFF AUTO. Set it manually to whatever the setting is that keeps in at stock speeds. I would also remove the 2gb module to make sure that the issue isn't linked to RAM module compatibility.

Temps look very, very good, so no worries there. When stress testing with a program like Prime 95, I suggest running it for more than a hour. I ran it for almost 5 hours on my system and found a error. I backed it down from 3.6ghz to 3.5 and it was good for all 5 hours.

Did you take the PCIe off auto as well? You don't want to OC the PCIe bus and it will automatically increase as you OC the CPU. Same for the RAM.

The video, though very shaky, gives us great information. It appears that your motherboard refers to the NB strap as "(G)MCH frequency latch", possibly stands for (Gigabyte) Memory Controller Hub Frequency Latch.

First, I would change the "Fine CPU clock ratio" to 0.0. I usually tend to start overclocking with 9x rather than 9.5x, as I leave that extra 0.5 for last.
Next, set your "(G)MCH frequency latch" to 333, which should be the loosest and most easily stable, and set your "System Memory Multiplier" to 3.20B for now. The video shows that you have set your Vcore to 1.29375V. This is a little bit high to start out. I would maybe at least adjust this to 1.27500V. We can keep the "CPU Termination" at "normal" or we could set it to 1.20V. I won't want to change it to anything higher, as I don't know if this means you are telling to board to do something like load line calibration.

Now, I would usually overclock at increments of 10s at first and then in 5s for the "CPU Host Frequency". I know Martell1977 has mentioned that you would want to run prime95 for an extended periods of time, but I usually leave that AFTER I have completed my overclocking and gotten to where I want to be. Running prime95(small FFTs) for 30mins is my usually way of a quick-&-dirt test to see if I have enough voltage supplied to the CPU in the first place. The reason I also suggest having CPU-z open is to see a rough estimate of the voltages. Due to Vdroop, the displayed CPU voltage will be higher at idle and lower during load. The more you push the CPU to work harder, the lower the CPU voltage will go. At some point, there wouldn't be enough voltage to compensate, and your CPU will start spitting out errors during the test, or possibly even BSOD. The E8500 should be ok usually with just 1.20V at load.

Remember to also run Memtest as well afterwards. Memtest is very important as a stability test. (this is the link to their site: http://www.memtest86.com/). You need something like Rufus to make it into a bootable USB.

Oh and here are a few links to people who have a similar build to yours playing Need for Speed Rivals.
E8400 + GTX 650: https://www.youtube.com/watch?v=iJK7Uelbg_Q
E8500 + GTX 750Ti: https://www.youtube.com/watch?v=oeL_jD50Nf4
E8500 + GT 430: https://www.youtube.com/watch?v=jt8C07SHnrk
Your GPU should be fairly decent already. All you need is to maybe finish OC your CPU. E8500 @ 3.7GHz should be at around the level of a non-overclocked i3-2120 with no hyperthreading.

Sorry for bumping an old thread, but ive got my E8500 to 4.5Ghz stable with 1.58v and 473Mhz FSB. Using a Gigabyte Ga-EP31-DS3L motherboard. I can provide a pic of my BIOS if you need it. I havent tweaked the settings much for them to be optimised, ive just tried to run it as fast as possible.