Overclocking a Phenom II 940

[TheHostileGamer]

Hey guys, semi noob here. Just wanted to introduce myself to to everyone and show some AMD/Ati love! I'm looking forward to reading some of the how to guides for the Phenom II 940 AM2+. I already have a stable overclock of 3.517ghz on air, but I see some users able to push it higher than that. I haven't tweaked anything but the the multiplier (x17.5) and was interested in seeing what some of you have gotten to with different configurations. Heres my specs:

 

AMD Phenom II 940 AM2+ @ 3.5ghz

Ocz ddr2 4gb @ 1066

Asus M4A78 Plus motherboard (cheap I know)

ATI HD4870 512mb video card

550w Antec truepower 2.0 PSU

 

Im going to attach a pic of the PC so you see the type of airflow and cooling I have. All of your comments and suggestions are much appreciated and I look forward to reading though the forum and joining in as much as I can. Thanks! Oh and if I have alot of typing errors I'm blaming it on this new razer lycosa keyboard...still trying to get used to these keys!

 

 

 

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[sack_patrol]

Hiya f!ver.

 

Well...as you said the motherboard is in fact cheap and it might hold your cpu back from it's full potential.

I can suggest for you some mobos that are the following:

MSI 790FX-GD70 (this one is on the top of my personal list although I didn't get it)

DFI LanPary M3H5 (one that I have currently...I've had no problems and I'm happy)

Gigabyte have good motherboards that are cheap AND deliver but I'm not up to date with their products.

 

I made a little guide a while back for other users that had phenom cpus and I can offer you that, it might help you and give u some tips. I've referenced some real nice real guides for overclocking too.

__________________________________________________________________________-

 

Setup

1.1- Get new cooler.

Suggestions:

Prolimatech Megahalems (no fans included)

Sunbeam Core Contact Freezer 4 (120mm fan included with new technology for quieter and faster fans)

Scythe Ninja 2 (120mm fan included)

Zalman 9700 with integrated fan (LED's on certain models, comes with big useless control module thingy)

Coolermaster V8 (overkill, expensive, not much better than the others)

 

1.2- Get thermal paste...something like Arctic Silver 5. I find it to be quite good.

 

Overclocking

2.1 - Read guides for overclocking the Black editions.

Suggestions:

Dolk's Guide on overclocking Phenom II's : http://www.techreaction.net/forums/showthread.php?t=367

 

2.2 - I guess I won't really tell you anything new that won't be said in the guide but it might be helpful for the start.

 

2.2.1- Look on AMD's website for your CPU's specs and what max temperatures are. So that you know when it's getting too hot to move forward (it will most probably be somewhere around 60C.)

 

2.2.2- Black Editions overclock using multiplier mostly. FSB can also be used but it's gonna overclock your ram and you NB as well as the CPU so a little

more to consider when using it.

 

2.2.3- When you start the overclock,the first thing to do is to disable the Cool 'n' Quite Feature in your Bios which will let you overclock. simply increase the multiplier in your BIOS by .5 or 1 and test after each increase. (look in testing software) After you start getting bsod, crashes or other abnormalities it's time to increase the voltage a little. Then try again, test, watch temps, repeat. You should probably back off when you reach around 1.5 voltage.

 

2.2.4- Simply increase the multiplier in your BIOS by .5 or 1 and test after each increase. (look in testing software) After you start getting bsod, crashes or other abnormalities it's time to increase the voltage a little. Then try again, test, watch temps, repeat. You should probably back off when you reach around 1.5 voltage.

 

2.2.5- After only increasing the voltage no longer works, if you want to try and push the CPU further, try increasing the CPU-NB Frequency. (stock multi is at x10 and 1.1V) Don't push it too much as well. No more than x13. If overclock doesn't work on x13 or x12 then you've probably reached the maximum for your CPU. If you still want to overclock there might be a way but it's pretty advanced stuff which you will learn through time.

 

2.2.6- After you are satisfied with your overclock you will need to test for 24 hourse for stability. If you do not achieve it, you will need to tinker with the bios a bit more. For example, ram could affect stability, tighten the timings or loosen them up. Either could increase stability, but it is up to you to decide if it's worth it. If not then try increasing a bit the CPU voltage and test again. If it still doesn't work. Then you will need to back of by .5 on the CPU multi, but leave the voltage, then it will probably be stable.

 

Testing

3.1 - Download some software that will help you monitor the temperatures and status of your PC as well as stress it to test for stability.

Suggestions:

CPU-Z (most known and usefull program for system specs)

Everest (excellent for monitoring everything!)

Core Temp (specifically for temperature monitoring)

Hardware Monitor (yet another useful program for monitoring voltages, fan speeds etc.)

 

3.2 - Benchmarking and Stress Testing Software:

Suggestions:

OCCT (very good program for testing for stability. 15 minutes should be enough for testing stability WHILE overclocking. 12 hours for final overclock - minimum.)

Prime95 (also a good program for testing. You will need to read so that you can understand how it works and be able to set it to priority 10 for maximum stress)

LinX (Run 30 times with memory usage set to "ALL" and you should have an idea if the overclock is stable.)

Intel Burn Test (Don't worry, it works for AMD too, but you need the latest version. It should quickly tell you if your overclock is stable an hour is enough I've heard.)

 

 

Warnings and additional tips:

1: Always watch the temp and voltage as it could damage the CPU greatly.

2: Know your limits. When the CPU reaches the wall, then accept it. (I learned that the hard way)

3: Learn your bios and settings, set them all or as much as possible to manual so you know that whatever you have set it, then that's what it is. No secrets.

4: If for some reason you can no longer get into the BIOS due to an overclock gone horribly bad, just reset CMOS. That will set bios settings to default and you will be able to continue your work.

5: Update bios! It can help when overclocking. (be careful though as a bios update could go very wrong and have serious consequences if don't wrong)

6: Some small tricks for calculating:

CPU SPEED: CPU Multiplier x FSB = CPU SPEED (lets take my 550 for example.: x15.5x200=3.100Ghz)

NB SPEED: Almost the same as above: NB multi x FSB = NB Freq. (it's all tied to the FSB but it's not necessary to use it when overclocking a Black Edition. Makes you life easier.)

7: If your CPU is stable but you still want, you could tighten ram timings for a few more drops of speed. Guide on timings: http://www.overclock.net/faqs/26706-info-r...gs-dummies.html

[TheHostileGamer]

Hmm didn't know that the NB and the HTT were so important when overclocking a CPU. I went into my BIOS and it says thet 1.8ghz is the max my NB can go, so really is there even a point to OC the cpu if its just going to bottleneck at the NB?

[sack_patrol]

If the NB turns out to be the factor that will determine weather there is a big or no speed increase then I guess it would. As I said before, the mobo will probably hold the CPU back. Are you sure your looking at the right stuff in the bios and that this is in fact the NB req? Phenom II's default NB frq is 2000.

[TheHostileGamer]

I thought the AM2+ version of the Deneb core only went to 1.8ghz (example: http://images.bit-tech.net/content_images/...henomii940.png)

Since I have a cheapy mobo you think they lock it to 1.8ghz? I wonder if I went to a 790FX MSI like you said it would give me options for that kind of stuff, but if I get a new mobo I might as well go all AM3 with a new 6 core AMD. I'm beginning to think that sitting here at my 3.5ghz on air and doing superpi 1M @ 19.8 seconds will be good enough for the games I play, cause thats all I really do on this PC.

[Boinker]

Well, you made it to where I did on air. Mine right now is 4 hours Prime95 Stable at 3.7Ghz @ 1.45volts and is occt 1 hour stable. The phenom 2 940 does well as far as overclocking goes after to you get the temps to a reasonable range. water after about 3.60 may be a good upgrade solution. Fir my curiocity where is your vcore at?

 

Edit: BTW if you are talking about the 1.8Ghz setting you are refering to the HT bus... It is also like that on mine. With the am2+ phenom's its there and locked and with the AM3 they set it to 2.0Ghz Hyper transport bus speed. The northbridge stock for the phenom is a multiplier of ten or at 2000Mhz with 1.10 volts nb temp. I have mine set to 11x with the overclock at 3.70 Ghz and the northbridge overvolted to 1.26 to compensate for the increase in chip clock. (I may be able to lower it though).You may also need to up your CPU-NB voltage later, mine is at 1.35volts and it may be neccesary to increase to VDDA and southbridge voltage in addition to that. but there really is no majic setting here. some people have been able to move phenom II to 3.80 without additional voltage or adjustment other then the multi.... But as they say everychip is different. Hopefully you can get it good and up there without much trouble. good luck. Brenton.

 

Also This guide to overclocking that chip is good.

Edited December 19, 2009 by boinker

[sack_patrol]

I thought the AM2+ version of the Deneb core only went to 1.8ghz (example: http://images.bit-tech.net/content_images/...henomii940.png)

Since I have a cheapy mobo you think they lock it to 1.8ghz? I wonder if I went to a 790FX MSI like you said it would give me options for that kind of stuff, but if I get a new mobo I might as well go all AM3 with a new 6 core AMD. I'm beginning to think that sitting here at my 3.5ghz on air and doing superpi 1M @ 19.8 seconds will be good enough for the games I play, cause thats all I really do on this PC.

uuuuh don't get a 6 core not unless you want to turn your PC into a benchmark....then you'd better get..like 3 of the newest VGAs...and overclock em...get more ram etc. If you want the PC to be for normal use...like play the newest games...check mail stuff like that a dual core will do as even quads aren't that popular yet in the sense that games don't take advantage of it yet. I don't even wanna think of the price of a 6 core cpu.

[insan3]

1000 easily

[sack_patrol]

1000 easily

DAYUM!

[potatochobit]

your overclock is fine, I don't think it will go much higher anyway

dont'waste your money on coolers and boards or what not

save for when you get a new build this coming year and do it then

[TheHostileGamer]

Fir my curiocity where is your vcore at?

 

In my BIOS I'm up +150Mv on my vcore and +100Mv on my NB

[TheHostileGamer]

Just a little edit, I recently updated my BIOS from the 1101 version to the most current and it seems now I have more options when overclocking my HTT. So know I'm running 3.4ghz core and 2ghz HTT and I'm Prime95 stable for an hour so far. (writing this & running prime 95 right now)