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I read a few guides but i still seem to be confused on what to do specifically step by step, I don't wanna accidentally screw something up in the BIOS settings. I'm using a Asus P5QL/EPU motherboard and 4GBs Kingston DDR2 value RAM 800Mhz. I'm completely new to this... I see a lot of gamers do it and I hear my CPU is pretty good at overclocking for the most part so I was curious to see how much extra performance I can squeeze out of it without having to worry about stabilization.


Mobo overview
http://www.asus.com/Motherboards/Intel_Socket_775/P5QLEPU/

You'll easily be able to get that CPU to more than 3.4ghz stable. C2D's overclock really well, and I've gotten >1ghz overclocks with them. Given, you have to have good cooling, and you have to make sure your ram supports the higher fsb speeds.

eliplan312 wrote:

You'll easily be able to get that CPU to more than 3.4ghz stable. C2D's overclock really well, and I've gotten >1ghz overclocks with them. Given, you have to have good cooling, and you have to make sure your ram supports the higher fsb speeds.

Well I have a Zalman 9500CNPS for cooling. As for the RAM, how do I find out if it supports higher FSB speeds or not?

And yes I understand I can get it over 3.4 stable but I don't wanna have to go through the process of stress testing and going back and modifying it 15 times to make it work, I'm new to this so I'd rather not dive in to the deep end from the get-go. lol

RAM model: KVR800D2N6K2/4G

Your CPU cooler certainly would be able to handle the higher clock speeds, however since your ram is rated for 800 you might have to fiddle with timings, but that shouldn't be too much work.

As for stress testing you really should go through the routine of stress testing each overclock. It'll save you lots of trouble in case the overclock actually isn't stable.

I have an e8400, super easy overclock. I just raised the FSB from 333 to 400, insta overclock from 3.0 to 3.6, did not even have to play with voltage or memory. Runs completely stable, although your milage may vary .

I'm not familiar with that board in particular, but you should be able to change the FSB to increase the CPU speed with default multiplier and then change your memory ratio to keep it at its rated speed. If my math is correct (and it very well could not be) your chip runs by default at 3GHZ or 3000 MHz. Your FSB is 1333, but it's quad-pumped so the actual base is 333 MHz and your proc. multplier is 9 so 333 x 9 = 3000 or 3GHz (I think). Your memory is 800 MHz, but it's DDR, so its "effective" speed is 800, but its actual speed is 400 MHz, so its multiplier is something like 1.2 currently - 333 x 1.2 = 400 >> x2 = 800 Mhz DDR2. Alright, now that we know what the stock picture looks like (and your bios should reflect this under one of its scrrens - probably "Advanced Config" or somesuch menu) we can talk about what to change to overclock. I always like to stick with somewhat logical values as I typically just want to get a boost from my system without using it as a space heater or otherwise risking premature failure of other components. So, in your case, if you want to target 3.4 GHz, you're looking at an FSB of 378 or so - that's not very "round" - in order to keep your memory at 800 MHz (and you probably want to with value type RAM) you would need a memory multiplier of 1.06, which you probably don't have. You might have 1.1, though, which would run the RAM at 416MHz which translates to 832 in DDR terms. I think it would probably do it, but it might cause some instability. Who knows, I had some "budget" DDR2 during the time where mem manufacturers seemed to forget how to make low latency RAM and it happened to be a batch that ran super low timings and overclocked like the dickens. YMMV.
Anyways, back to "round" numbers. Another option to look at would be to increase the FSB even more to 400MHz if your board can handle it (an ASUS would I think) and then you're either looking at running the processor at 3.6GHz (which might be possible with your cooling) or dialing back the multiplier to 8, which would put your CPU at 3.2GHz (not great) but then your board would almost certainly have a 1:1 multiplier to keep your memory at stock speed.
In the end, it's a balancing act of what your components are capable of doing on their own and as a system. If your RAM can run at higher speeds with stock voltage, great. If your CPU is a screamer, you might have to drop your mem speed in order to accomodate that. Be careful about adjusting voltages much higher than stock, that's when power usage skyrockets and you can literally fry your components. Overall, you're trying to improve performance, but don't sacrifice stability and most of all, have fun with it.

frumper15 wrote:

I'm not familiar with that board in particular, but you should be able to change the FSB to increase the CPU speed with default multiplier and then change your memory ratio to keep it at its rated speed. If my math is correct (and it very well could not be) your chip runs by default at 3GHZ or 3000 MHz. Your FSB is 1333, but it's quad-pumped so the actual base is 333 MHz and your proc. multplier is 9 so 333 x 9 = 3000 or 3GHz (I think). Your memory is 800 MHz, but it's DDR, so its "effective" speed is 800, but its actual speed is 400 MHz, so its multiplier is something like 1.2 currently - 333 x 1.2 = 400 >> x2 = 800 Mhz DDR2. Alright, now that we know what the stock picture looks like (and your bios should reflect this under one of its scrrens - probably "Advanced Config" or somesuch menu) we can talk about what to change to overclock. I always like to stick with somewhat logical values as I typically just want to get a boost from my system without using it as a space heater or otherwise risking premature failure of other components. So, in your case, if you want to target 3.4 GHz, you're looking at an FSB of 378 or so - that's not very "round" - in order to keep your memory at 800 MHz (and you probably want to with value type RAM) you would need a memory multiplier of 1.06, which you probably don't have. You might have 1.1, though, which would run the RAM at 416MHz which translates to 832 in DDR terms. I think it would probably do it, but it might cause some instability. Who knows, I had some "budget" DDR2 during the time where mem manufacturers seemed to forget how to make low latency RAM and it happened to be a batch that ran super low timings and overclocked like the dickens. YMMV.
Anyways, back to "round" numbers. Another option to look at would be to increase the FSB even more to 400MHz if your board can handle it (an ASUS would I think) and then you're either looking at running the processor at 3.6GHz (which might be possible with your cooling) or dialing back the multiplier to 8, which would put your CPU at 3.2GHz (not great) but then your board would almost certainly have a 1:1 multiplier to keep your memory at stock speed.
In the end, it's a balancing act of what your components are capable of doing on their own and as a system. If your RAM can run at higher speeds with stock voltage, great. If your CPU is a screamer, you might have to drop your mem speed in order to accomodate that. Be careful about adjusting voltages much higher than stock, that's when power usage skyrockets and you can literally fry your components. Overall, you're trying to improve performance, but don't sacrifice stability and most of all, have fun with it.

Thanks for the replies first of all, it's definitely clearing things up for me. So basically my real limiter here is how well my RAM overclocks since my FSB is advertised by Asus to overclock to 1600Mhz, so that part won't be the issue. I'm crossing my fingers for my value RAM, I only went with it because DDR2 ram is so freakin expensive still and there are like zero higher end RAM models on the QVL that are still being sold. But yea in a little bit I will probably try the easy way first and overclock the FSB to 400Mhz then run Memtest after I reboot to see if it can handle it.

Before I overclock is it possible to set the FSB to 400Mhz, leaving the CPU multiplier at 9 (making it 3.6Ghz) while making the memory multiplier 1.1 making it 880Mhz?

Edit: I checked my BIOS, I can't seem to find the multiplier settings. The only one available that I see is the FSB frequency setting. =/

It seems as if the mutiplier isn't available on my BIOS. A little on the odd side.

What I can do is modify the FSB speed and my RAM speed (667, 800, etc, Auto)

You need to set the RAM speed to 667 and the FSB to 400. You'll then get the CPU to 3600 and the RAM running back at 800. The 667 label assumes you're running the standard 333 FSB (it's really the 2:1 multiplier setting), so the 400MHz FSB will give you the 800MHz RAM speed.

However it is essential that you do the appropriate stability and stress testing with any overclock you try (Memtest and Prime95 are a good starting point). My E8400 would boot into Windows OK at 3.6 on stock volts, but wasn't 100% stable under load. There's a definite risk that you could corrupt your Windows installation sooner or later if you adopt an untested overclock. With a good cooler, there's no harm in upping the CPU voltage a little to help stability, but don't get carried away and keep an eye on the temperature (CoreTemp is good for this). Note that different individual Core 2 CPUs will have different stock voltages, so use something like CPUID to check what voltage yours is running at before changing any settings.

It might seem boring, but it would be better to step up in small steps, checking the stability each time. You'll also get more of a feel for the limits of your different parts that way. I'd suggest setting the RAM to 667 right from the start to try to take this out from being the limiting factor until you get the FSB above 400.

MrJP wrote:

You need to set the RAM speed to 667 and the FSB to 400. You'll then get the CPU to 3600 and the RAM running back at 800. The 667 label assumes you're running the standard 333 FSB (it's really the 2:1 multiplier setting), so the 400MHz FSB will give you the 800MHz RAM speed.

However it is essential that you do the appropriate stability and stress testing with any overclock you try (Memtest and Prime95 are a good starting point). My E8400 would boot into Windows OK at 3.6 on stock volts, but wasn't 100% stable under load. There's a definite risk that you could corrupt your Windows installation sooner or later if you adopt an untested overclock. With a good cooler, there's no harm in upping the CPU voltage a little to help stability, but don't get carried away and keep an eye on the temperature (CoreTemp is good for this). Note that different individual Core 2 CPUs will have different stock voltages, so use something like CPUID to check what voltage yours is running at before changing any settings.

It might seem boring, but it would be better to step up in small steps, checking the stability each time. You'll also get more of a feel for the limits of your different parts that way. I'd suggest setting the RAM to 667 right from the start to try to take this out from being the limiting factor until you get the FSB above 400.

Now I'm getting a little iffy hearin that I could lose my OS. I didn't realize overclocking was so risky. =/

I can't recall ever losing an OS from an overclock.

The fundamentals are this:

1. Overclock your CPU by increasing you FSB.
2. But increasing the FSB also increases the memory speed...
3. Therefore, lower the memory multiplier so the final result is that raising the FSB brings the memory back to its original speed.

So if you have 800MHz RAM, set it to 667 in the BIOS and then raise the FSB till you get the RAM back to 800. Taking MrJP's word for it, that's 400 FSB, at which point your E8400 will be running at 3600 MHz.

I'd be very shocked if an E8400 didn't do 3600 MHz at stock voltage - even on the stock cooler - with complete stability.

When I was still running an e8400, I had it OCed to 3.6GHz at stock voltage, pretty much everything set to auto on my gigabyte ep45-ds3r. Just set the FSB to 400mhz, pci bus to 100mhz manually and that should do it.

totally agree bro. And you dont even have to have a massive cooler to OC d E8400.
getting it to work @3,6GHz is free. just make sure dat when u chande d FSB to 400Mhz,
check d RAM frequency, choosing d respective multiplier to achieve its nominal frequency.

flip-mode wrote:

I can't recall ever losing an OS from an overclock.

The fundamentals are this:

1. Overclock your CPU by increasing you FSB.
2. But increasing the FSB also increases the memory speed...
3. Therefore, lower the memory multiplier so the final result is that raising the FSB brings the memory back to its original speed.

So if you have 800MHz RAM, set it to 667 in the BIOS and then raise the FSB till you get the RAM back to 800. Taking MrJP's word for it, that's 400 FSB, at which point your E8400 will be running at 3600 MHz.

I'd be very shocked if an E8400 didn't do 3600 MHz at stock voltage - even on the stock cooler - with complete stability.

Here's the thing though. I searched through my BIOS and I can't even find the multiplier for the CPU or the memory. It just seems like a non-existent setting in there but it's weird because they advertised the motherboard as overclockable which kinda makes it pointless if u don't get those two settings. I can only increase the FSB speed and change the memory to a fixed speed which idk if it works when you're overclocking the FSB.

I don't think I can overclock value ram too much here so unless I can keep it at stock or near stock speed, I don't wanna risk it.

I downloaded the manual for your mobo. You want to look on page 2-12 and 2-13. You want to go into the BIOS and the "AI Tweaker" menu and:

Edit the "AI Overclock Tuner". Set it to "Manual". Once you do this, the manual say some new menu options appear - including "FSB Frequency"
Edit "FSB Frequency". The default should be 333. Set it to 400. Your E8400 has a multiplier of 9, so 9*400 = 3600.
Check "PCIe Frequency" and make sure it is set at 100. Never let the PCIe frequency get overclocked.
Edit the "DRAM Frequency". Set it to 667. That should result in it running at 800 Working from the FSB ratios above, 333 / 400 = 667 / 800, so in other words you've lowered your DRAM multiplier just the right amount to offset the amount that you have raised the system bus frequency.

That's all you need to do. Save those settings and reboot. Those settings are almost guaranteed to work. But if your computer refuses to boot, reset the CMOS (i.e. the BIOS), set the DRAM back to 667 again, and try a lower FSB frequency like 366 or so.

Mystic-G wrote:

flip-mode wrote:

I can't recall ever losing an OS from an overclock.

The fundamentals are this:

1. Overclock your CPU by increasing you FSB.
2. But increasing the FSB also increases the memory speed...
3. Therefore, lower the memory multiplier so the final result is that raising the FSB brings the memory back to its original speed.

So if you have 800MHz RAM, set it to 667 in the BIOS and then raise the FSB till you get the RAM back to 800. Taking MrJP's word for it, that's 400 FSB, at which point your E8400 will be running at 3600 MHz.

I'd be very shocked if an E8400 didn't do 3600 MHz at stock voltage - even on the stock cooler - with complete stability.

Here's the thing though. I searched through my BIOS and I can't even find the multiplier for the CPU or the memory. It just seems like a non-existent setting in there but it's weird because they advertised the motherboard as overclockable which kinda makes it pointless if u don't get those two settings. I can only increase the FSB speed and change the memory to a fixed speed which idk if it works when you're overclocking the FSB.

I don't think I can overclock value ram too much here so unless I can keep it at stock or near stock speed, I don't wanna risk it.

Thats what makes the 3.6 the sweet spot. I ran my e8400 at 3.6 for Years without a voltage bump, the auto memory setting making my ram run at its rated 800mhz. I actually up to 4.2 but needed alot of voltage to be happy there. I was using 4 x 2gb of corsair value ram. I don't recall having to set the memory to 667 first, but I had an evga board and not an ASUS. I have never lost a os install to a overaggressive overclock. Just had to clear the cmos a few times (either a jumper setting or remove the mb button battery).

Good luck

Starfalcon wrote:

I have an e8400, super easy overclock. I just raised the FSB from 333 to 400, insta overclock from 3.0 to 3.6, did not even have to play with voltage or memory. Runs completely stable, although your milage may vary .

I've got that exact configuration and my e8400 has been running 100% stable since early 2008... I'll trade it out when it dies or, more likely, when Haswell shows up

flip-mode wrote:

I downloaded the manual for your mobo. You want to look on page 2-12 and 2-13. You want to go into the BIOS and the "AI Tweaker" menu and:

Edit the "AI Overclock Tuner". Set it to "Manual". Once you do this, the manual say some new menu options appear - including "FSB Frequency"
Edit "FSB Frequency". The default should be 333. Set it to 400. Your E8400 has a multiplier of 9, so 9*400 = 3600.
Check "PCIe Frequency" and make sure it is set at 100. Never let the PCIe frequency get overclocked.
Edit the "DRAM Frequency". Set it to 667. That should result in it running at 800 Working from the FSB ratios above, 333 / 400 = 667 / 800, so in other words you've lowered your DRAM multiplier just the right amount to offset the amount that you have raised the system bus frequency.

That's all you need to do. Save those settings and reboot. Those settings are almost guaranteed to work. But if your computer refuses to boot, reset the CMOS (i.e. the BIOS), set the DRAM back to 667 again, and try a lower FSB frequency like 366 or so.

OK thank you very much. I finally grew a pair and did exactly what you said. Now I have a weird issue... when I'm at the BIOS post screen it says I'm at 3.6Ghz but in Windows My Computer properties tells me it's 3.0 aswell as CPU-Z and SpeedFan. Is something going on that's rolling it back or are they just reading stock information?

OK thank you very much. I finally grew a pair and did exactly what you said. Now I have a weird issue... when I'm at the BIOS post screen it says I'm at 3.6Ghz but in Windows My Computer properties tells me it's 3.0 aswell as CPU-Z and SpeedFan. Is something going on that's rolling it back or are they just reading stock information?

This could be due to the ACPI interface. I normally run Linux with my OC'd e8400 and cpuinfo reports 2 CPU speeds: 1998Mhz in "low" mode and 2997 Mhz when I kick a process up to high CPU usage. I do know that my system *is* overclocking despite the reported speed due to benchmarks that I run before & after the overclock. You should try some quick benchmarks before & after to check it out yourself. If you really want to see the high-speed, try disabling ACPI power management for the CPU in Windows (I'll leave the details to Google on that bit).

Mystic-G wrote:

OK thank you very much. I finally grew a pair and did exactly what you said. Now I have a weird issue... when I'm at the BIOS post screen it says I'm at 3.6Ghz but in Windows My Computer properties tells me it's 3.0 aswell as CPU-Z and SpeedFan. Is something going on that's rolling it back or are they just reading stock information?

Dunno what that could be. Perhaps those apps are looking at the CPU model info and reporting what it should be instead of what it really is. No idea. I suggest running some benchmarks and leaving CPU-Z open during that time. And see what improvement you get from the benchmarks, too.

flip-mode wrote:

Mystic-G wrote:

OK thank you very much. I finally grew a pair and did exactly what you said. Now I have a weird issue... when I'm at the BIOS post screen it says I'm at 3.6Ghz but in Windows My Computer properties tells me it's 3.0 aswell as CPU-Z and SpeedFan. Is something going on that's rolling it back or are they just reading stock information?

Dunno what that could be. Perhaps those apps are looking at the CPU model info and reporting what it should be instead of what it really is. No idea. I suggest running some benchmarks and leaving CPU-Z open during that time. And see what improvement you get from the benchmarks, too.

I left CPU-Z open while running Bad Company 2 and seen it showing it running at 3600Mhz under load so it's working correctly. I guess it's just not reporting it correctly.

Speedstep technology will underclock when cpu cycles are not needed. Your computer is reporting correctly.. 3.6 under load.

Thanks to all who helped me do this. Though it was relatively a easy task to do, I'm glad I finally got to do this. I might come back and ask for tips when I get a quad core for BF3. lol...

Good job Mystic-G. Glad you got it going. Easy, fun, free performance increases = win.

That's too bad you're stuck with 800Mhz RAM.

As others have said, the E8400 is perfectly capable of a 450x9 FSB-to-Multiplier - Been running mine that way for nearly two years.

PainIs4ThaWeak1 wrote:

That's too bad you're stuck with 800Mhz RAM.

As others have said, the E8400 is perfectly capable of a 450x9 FSB-to-Multiplier - Been running mine that way for nearly two years.

Yea... I'll stick with it too because DDR2 RAM is hella expensive and I doubt I'll find too many 1066 or 1333 sticks at a reasonable price that are also compatible with the board.

You shouldn't feel too bad about it. Penryn at 3.6 is pretty darn fast, unless you need lots of cores, which no amount of overclocking will bring.

flip-mode wrote:

You shouldn't feel too bad about it. Penryn at 3.6 is pretty darn fast, unless you need lots of cores, which no amount of overclocking will bring.

Yea I understand. I'm still gonna end up buying a quad core for Battlefield 3, but I figured since I am why not just go ahead and overclock this CPU while I still have it. This is probably gonna have me lean toward overclocking C2Q Q8400 (what i'm probably gonna buy) to see how much I can get out of it.

Most C2 quads have very little OCing headroom in them. Most of them will usually not OC much above stock, and even if they do they usually will not be very stable.