How to safely OC Phenom II x4 940 to 3.5ghz

Hello, I'd like to overclock my CPU to a stable level, maybe to 3.5 or 3.6 ghz. I would like to know if this is possible to do without replacing the stock cpu cooler that came with it. I'm new to overclocking and this is the first time that I'll be doing this. I'm afraid to mess up my whole system so I'm hoping to get some good advice from the overclocking experts in this community. I read an article here:

http://www.techspot.com/review/142-phenom2-overclocking/page2.html

and from what I've understood is that they only changed the multiplier from 15 to 18 in the bios and retained the stock fsb and voltage settings to achieve 3.5 ghz. Will this also work for my setup?

Phenom II x4 940 3.0 Ghz AM2+
Asus M3A78-CM
ocz ddr2 8500 gold edition 4gb (2x2gb) 5-6-6-18
corsair 750w
sapphire 4890 new edition
win xp pro 32bit

I'm looking forward to your replies, thanks!
29 answers Last reply
More about safely phenom 5ghz
  1. Maybe..But why chance it? I assume you paid close to $170 for this cpu. Isn't worth a $40 investment to ensure it doesn't fail?

    Most folks can achieve 3.4 Ghz without any voltage changes. 3.5 Ghz is typically where we need to add a little voltage to gain absolute stability, but as they saY your mileage may vary.

    I highly recommend you invest in an aftermarket cooler before doing any overclocking, but its your cpu.
  2. 18X 200= 3.6 Ghz. Not likely to be stable without a little more voltage, but it could be a "lucky" part.
  3. Thanks for the repy buzznut, I'm currently looking at corsair's H50 cooler, I think it's quite expensive at $80, I'm still looking for online sales. In your opinion, is it worth to clock it to 3.4 ghz for now and use the stock fan? And what combination of fsb and voltage and multiplier should I set it to get it to 3.4 ghz? Can I just adjust the multiplier without adjusting anything else?
  4. 3.2 GHz on the stock HSF is fine. Anything higher and an aftermarket HSF is required. It's up to you.

    Do not forget to test with prime 95 to make sure your maximum peak temperature is within the safe limit.
  5. Here ( http://www.tomshardware.com/reviews/phenom-overclock-athlon,2161.html ) you can find the way to OC your CPU to 3.5GHz and more.
  6. +1 above, that is the article you want to read. Great primer for AMD overclocking!
  7. BTW, I hear good things about the corsair cooler, but you will get similar results with a toip end air cooler. Look at Zalman coolers, Xigmatek 1283, Thermalright ultra 120. Check Frostytech.com for reviews on new coolers.
  8. Also the Scythe Mugen-2 is unbeatable at 35$ from newegg. It's huge though so make sure it fits in your case.
  9. I like the einstein quote. Mirrors my thoughts on the subject of stupidity exactly.
  10. buzznut said:
    I like the einstein quote. Mirrors my thoughts on the subject of stupidity exactly.


    ----------------------------

    jeje, maybe have some mistake in the spelling or grammar.....I'm not from USA, and my native language isn't the english.
  11. Actually it looks about as right as right ever gets.
  12. How to safely OC Phenom II x4 940 to 3.5ghz ? Easy, just up the multiplier to x17.5 and raise the CPU vid to 1.35/1.36v and you are done (assuming you have the correct RAM timings and voltage). An aftermarket cooler will be needed as well...
  13. +1 for aftermarket cooling. In a pinch http://www.newegg.com/Product/Product.aspx?Item=N82E16835185125 the Freezer64 wont get you a record breaking OC, but its better than stock and pretty cheep. Was able to get 3.6 on my 940 with it.
  14. Thank you all for your excellent replies! I found an aftermarket cooler on sale, the corsair h50 $49.99 at fry's, I'll try to overclock after I install it. One last thing, is the program AMD overdrive from the amd game website any good or should I just use the bios?
  15. OvrClkr said:
    How to safely OC Phenom II x4 940 to 3.5ghz ? Easy, just up the multiplier to x17.5 and raise the CPU vid to 1.35/1.36v and you are done (assuming you have the correct RAM timings and voltage). An aftermarket cooler will be needed as well...


    Hello, can I oc if I leave the ram on "auto" settings in the bios? I didn't set the timings and voltage manually as I am afraid I might mess it up and cause the system not to boot.
  16. knilbeci said:
    Hello, can I oc if I leave the ram on "auto" settings in the bios? I didn't set the timings and voltage manually as I am afraid I might mess it up and cause the system not to boot.


    Yes you can but your pc is most likely to crash, there is no point in leaving your settings on AUTO when you can manually set the correct values for maximum stability. If you built your PC then it is highly recommended that you manually set your frequency/timings/voltage and you test one stick at a time using memtest or equivalent. This way you make sure that your ram is not faulty and you can go ahead and start overclocking ;)

    Some motherboards do not detect the correct values among other settings and that is what causes instability....
  17. too dangerous to leave everything on auto. set everything manually if possible.
  18. Hello,

    So here's my update guys, I was able to install the H50 liquid cooler, manually set the ram timings and OC my cpu in the bios. I am currently using a single stick of ram, 2gb ddr pc 8500, because my motherboard says it only supports one stick to be able to run it at full 1066. I'm using ocz gold ddr2 pc8500 2gb 5-6-6-18 @ 2.10 volts. CPU is OCed to 3.8 ghz @ 1.50++ volts (in the bios the max I could choose for cpu volt is +150 mv so I chose that, options are +50mv, +100mv + 150mv) I left the nbcpu volt to auto.

    CPU
    http://photos-a.ak.fbcdn.net/hphotos-ak-snc3/hs167.snc3/19470_1308014667350_1440063689_30884250_4819927_n.jpg

    Mainboard
    http://photos-g.ak.fbcdn.net/hphotos-ak-snc3/hs167.snc3/19470_1308014707351_1440063689_30884251_74229_n.jpg

    Memory
    http://photos-e.ak.fbcdn.net/hphotos-ak-snc3/hs167.snc3/19470_1308014747352_1440063689_30884252_6838294_n.jpg

    SPD
    http://photos-c.ak.fbcdn.net/hphotos-ak-snc3/hs167.snc3/19470_1308014787353_1440063689_30884253_2982341_n.jpg

    GPU
    http://hphotos-snc3.fbcdn.net/hs187.snc3/19470_1308014827354_1440063689_30884254_7684882_n.jpg

    Ok here's the question, why does my computer have "hiccups" lags for 1/2 second, even when i'm playing games like plants vs zombies, it's very noticeable, and especially when i ran 3dmark06, it shows the hiccups every 5 or 10 seconds. Is there something wrong with the way I OCed it causing the hiccups? Or is it because the memory is too small only 2gb?
  19. knilbeci said:
    Hello,

    So here's my update guys, I was able to install the H50 liquid cooler, manually set the ram timings and OC my cpu in the bios. I am currently using a single stick of ram, 2gb ddr pc 8500, because my motherboard says it only supports one stick to be able to run it at full 1066. I'm using ocz gold ddr2 pc8500 2gb 5-6-6-18 @ 2.10 volts. CPU is OCed to 3.8 ghz @ 1.50++ volts (in the bios the max I could choose for cpu volt is +150 mv so I chose that, options are +50mv, +100mv + 150mv) I left the nbcpu volt to auto.

    CPU
    http://photos-a.ak.fbcdn.net/hphotos-ak-snc3/hs167.snc3/19470_1308014667350_1440063689_30884250_4819927_n.jpg

    Mainboard
    http://photos-g.ak.fbcdn.net/hphotos-ak-snc3/hs167.snc3/19470_1308014707351_1440063689_30884251_74229_n.jpg

    Memory
    http://photos-e.ak.fbcdn.net/hphotos-ak-snc3/hs167.snc3/19470_1308014747352_1440063689_30884252_6838294_n.jpg

    SPD
    http://photos-c.ak.fbcdn.net/hphotos-ak-snc3/hs167.snc3/19470_1308014787353_1440063689_30884253_2982341_n.jpg

    GPU
    http://hphotos-snc3.fbcdn.net/hs187.snc3/19470_1308014827354_1440063689_30884254_7684882_n.jpg

    Ok here's the question, why does my computer have "hiccups" lags for 1/2 second, even when i'm playing games like plants vs zombies, it's very noticeable, and especially when i ran 3dmark06, it shows the hiccups every 5 or 10 seconds. Is there something wrong with the way I OCed it causing the hiccups? Or is it because the memory is too small only 2gb?


    Did you torture test at 3.8Ghz to ensure full stability? What resolution are you playing at?
  20. I'm playing at 1280 x 1024, oh I don't know about the torture test, which program should I download? This is my first time doing an overclock, I hope I know what I'm doing haha =D
  21. ^sysoft Sandra for 1 hour.
  22. You need to do a few things...

    1. Monitor temps

    2. Run prime95 : http://www.softpedia.com/get/Others/Home-Education/Prime95.shtml

    Leave your PC running prime for at least a few hours (blend test). Later on you can run large FFT's if needed.

    3. Make sure you have set all the correct values in your Display Properties (CCC)
  23. Hello,

    As soon as I ran prime95, windows crashed and rebooted but couldn't go back and load windows anymore, I went back to the bios and lowered down from 3.8 to 3.6 ghz but didn't change the voltage settings. It went back in windows. The temp at 3.8ghz before I ran prime 95 was 40-42 C with the h50 liquid cooler. I updated the catalyst drivers 9.12 and set 3d settings all to quality. I'm gonna run prime 95 again. Hope it works. I'll try the sandra after the prime 95. Thanks!
  24. Hey OvrClkr,

    Prime95 is still running in my other pc and the following tests were done and successful:

    On blend test:

    1024k
    8k
    10k
    896k
    768k
    12k

    Should I leave it on some more? How long will the whole blend test take? Will it loop back to the first test? It's been running for about an hour now.
  25. All 4 cores are at 100% load and the temp now is 50 C
  26. When I am done with a build I prime for no less than 24hrs. You do not have to leave your PC running that long but it is recommended.

    Your temps are fine =)
  27. Ok I'm happy with my current OC @ 3.6 Ghz it seems stable now after running prime95 for 3 hrs. I plan to run it again for 12 hrs later before going to bed. I inserted the other 2gb ram stick, still fast although I noticed that it's a tad faster with just a single stick @ 1066 compared to 2 @ 800. Thanks all very much for all your replies and suggestions! Happy new year!

    - knilbeci
  28. 4Gb's of 800 is actually a boost in performance gaming-wise as opposed to a single 2Gb stick of 1066. If you lower the frequency to 400 and tighten the timings a bit you will be surprised =)

    If all you are doing is using your PC to overclock and type(mess around) then you do not need more than 2Gb of RAM....
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