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Help Overclocking AMD Phenom II X4 945

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January 25, 2011 6:00:33 PM

Hello, I'm planning on overclocking my CPU, and would like some advice. I've done a good bit of research. I'm pretty sure my CPU is not a black edition, because I can only make my multiplier lower than stock, which is 15x.

Currently, my CPU reaches around 65-68C when playing a game like Bad Company. Now before you say anything, I know that with those temps I'm in no shape to overclock. However, I'm getting a new case and replacing the stock CPU cooler, which clearly isn't doing much, and though this was a good opportunity to overclock. I think the new cooler and case will drastically change these temps.

New Case: http://www.newegg.com/Product/Product.aspx?Item=N82E168...

Its even got its own CPU fan!

New CPU Cooler: http://www.tigerdirect.com/applications/SearchTools/ite...

I've heard ridiculously good things about this cooler. Even that it was as good as liquid cooling with 120mm Radiators. So I forgot about unappealing brown fans and suck it up. probably barely see it in the new case anyway.

So how high has the 945 gone? I've read some got it up to 3.6GHz with the stock cooler with a quick Google search, which is hard to believe. I think I got a basic understanding of how this overclock stuff works. So because my multiplier is maxed at 15x, I need to increase my Front Side Bus, which is at 200MHz. And Core speed is the product of CPU multiplier and FSB.

So when I increase my FSB I heard it was smart for beginners to go in increments of 10MHz, so it goes to 210MHz, and then my Core Speed is at 3.15Ghz. And you run Prime 95 for a couple hours and see if you temps are good on CPU-Z and you're done? Seems simple enough.

Now, I've heard some stuff about making sure that your voltage doesn't get to high, and I heard that 1.5 volts is high. Which is concerning, because according to CPU-Z, my "Core Voltage" is at 1.424V Idle, and at load 1.408V. Is that high? I never changed anything with my CPU, so I'm kinda surprised its that high. Should I worry about that or did I just expect it to be lower?

Thanks for the help everyone!
January 29, 2011 9:37:11 PM

100 views, 0 replies. Not bad at all.
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February 10, 2011 4:39:34 AM

those voltages dont sound right to me, i have the phenom 2 965 which runs at 3.4GHz normally, and my voltages were only 1.325 stock, so that might be why your temps are so high.
According to google your stock voltage should be 1.35, so i would go into your bios and manually lower it, then run prime95 and watch your temperatures, that should lower them considerably.

As for overclocking with the fsb you also have to take into account that raising the fsb doesnt just affect your processor, it also affects your ram and northbridge, so you want to make sure that those components can handle the extra speed. And you will definitely want better cooling, AMDs stock cooler doesnt give much overhead for overclocking. The Noctua would be fine.

After all of that you'll want to increase your fsb in increments of 5 until it will no longer boot into windows, then you'll want to lower it back down to the last stable setting and run prime95, if its not stable add the smallest amount of voltage you can and try again, then just repeat that until you have a stable overclock, making sure that you monitor your temperatures the entire time, and avoid letting it get over 55C

Hope that helps ^^
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February 13, 2011 6:12:20 PM

Well it's a good thing you getting a new cash and cooler, that's just ridiculous to me to have those temps. :p  But first off if you wanna overclock you need to disabled C1E and Cool n' Quiet. Once you do that your multiplier will not go down when your not doing anything. (this is not required but it's recommended for best OC).

Now because your voltage seems to be going down when your running Prime95, you most likely need to Enabled CPU Load-Line Calibration and PCIE Load-Line Calibration (LLC). You'll also want to disable the CPU and PCIE Spread Spectrum. That will stop the voltage from drooping at load.

Next you can use this technique I found. Do what I listed above and then set it to default settings along with AUTO voltages. Then go into the BIOS and if your BIOS tells you what the voltage is at AUTO then write it down. IF it does NOT show you, then open your OS and run CPU-Z and it will tell you the voltage there. Then go up by... 10MHz (so 210), now check the voltage again and write it down. Continue doing this until your voltage either a) doesn't go up or b) won't boot into the OS.

Once you have your voltages writen down, try to see if theres a "pattern". For mine, everytime I go up 100MHz my voltage goes up my ~.012v. Once you've got your aprox. voltage increase change it to the OC you want and adjust your voltage based on the previous step. For me I set mine to 4.0GHz meaning that I would need to add 1.08v more.
NOTE: This does not always work 100%. As it may boot up and do basic things, but it will not be fully stable!

Now if you followed what I said before you should try to run Prime95. It might look like it's working and that your temps are low, but don't get too excited. You should try to get Prime95 to run for AT LEAST 12 hours! If your CPU is not stable then you either a) Need to add more volts to your CPU, b)Your RAM Freq is unstable and you need to dumb it down or c)You have a bad chip and it's just not capable of that OC.

Hopefully this helped in your goal for a good OC. You have a good Cooler so I won't worry about that but I cannot stress enough... DO NOT UP THE VOLTAGE TOO MUCH! Look up what the MAX voltage should be on your chip, and DO NOT exceed it, putting it too high could FRY YOUR WHOLE CHIP!

Let me know if you need some more help. :) 
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February 21, 2011 12:54:53 AM

I was able to get my 945 stable @ 3.81 ghz after about 12 hrs of fine tuning. Actually my first real try at overclocking, here are some things I didn't know as much about when i first started and found out through research and trial & error throughout the day. The advice above is sound, disable cool n quite and c1e and spread spectrum first off.

Rig
Phenom II X4 945
2x XFX Radeon HD 4890 in Crossfire
MSI 790GX-G65 motherboard
4GB Corsair Dominator DDR3
Corsair TX850W PSU
ZALMAN CNPS10X PERFORMA cooler

Final settings:

FSB speed @ 254 (@ 15x multiplier its 3.81ghz)
Voltages: cpu 1.51, nb 1.28, ram 1.7

1- As you know the multiplier is locked so you have to resort to fsb tweaking. I knew that fsb also affects the northbridge and memory, what i didn't realize was the balance you have to strike between the three to get stable OC. I have good corsair dominator ddr3 which has a nice cooling solution, so i was able to pump 1.7v into the ram, and upped my nb voltage to 1.28 (i got this number of a forum post). Since we are forced to increase the FSB so much to get appreciable results, we cannot neglect the need to pump extra volts into the nb and ram for their own stability. This was my most crucial discovery. You see the experts say this over and over but i feel like not everybody really spends enough time tweaking these 2 components. I have a good mobo for overclocking i think, my nb is connected via a heatpipe to a huge vrm radiator with is directly between my cpu fan and exhaust fan so i like to think that helps. And like i mentioned my ram is very oc friendly.

2- Luckily i did not have to downgrade my ram frequency to accomodate the fsb increases. I did try that over several test runs and sometimes it did matter. I.e. i almost had a stable 3.9ghz oc by lowering my memory ratio from default 1:1.333 to 1.266 and 1.2, but prime95 failed after 5-10 mins consistently, so lowering cpu to 3.8ghz i was able to restore the ratio to default and maintain stability. You may want to tinker with this a bit as your system may be more stable by lowering the ratio. (i dunno the math, but i know there is a line where you benefit more by having more processor speed vs ram setting, so i THINK the best bet is to favor cpu speed over the memory frequency to a point. i.e. you would not want to lower the ram freq if it only results in a 50 mhz increase, but you WOULD lower it if it offered 200mhz, i don't know what those exact numbers are)

3- CPU voltage, i was a bit afraid of this but @ 1.51v my temps never go over 45c under prime95 heat testing. i plan to retest my rig again with lower volts for my piece of mind, but havent done that yet. Anyway, the point is don't be afraid to pump max volts if your coolers can handle it. i feel like my new zalman made this voltage possible.

4- google the crap out of "phenom 945 overclock" and read everything no matter how much it appears to be a repeat of what youve already read. Things like the 1.28 nb voltage was like 50 posts deep in the hundreth forum thread i read (not really but felt like it).

5- Chassis air flow, i don't know if this really helped or not, but make sure you have intake fans to force enough cool air in through the front. I also added one more above my video cards. Can't hurt so long as you keep negative pressure inside (i.e. slightly more air out than in)

6- manually set as many of your memory timings as possible. I don't know if this made much of a difference but lots of pros recommended so i followed their advice.

7- test test test and dont get frustrated by prime95 fails and crashes/locks. I am not known for my patience =) but i saw other newbie oc'ers able to get 3.8 so i made that my goal and didn't give up. 12 hours is a long time of tweaking and i was so tired of fiddling but i kept at it. I feel like a pro could push 3.9-4ghz on my rig, but i reached my goal and am happy for now. I do still need to run a marathon torture test, but the above settings all passed the entire memtest86 run and prime95 for 1 hour. I am going to run it overnight next weekend.

I feel like my voltages could go down a bit, i'll minimize those next. They all show red (danger) in my bios, but my research says they are within or ever so slightly above the recomended max (i think my cpu max is 1.5 but i have 1.51).

Again i am a newbie and i dont credit myself with anything but the research and patience, and maybe my components are just really solid individual pieces. But if i can do it anyone can! If only i could have more luck with my video cards!
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