rajiv babu

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Finally decided to OC my processor.......
Specs:
AMD Phenom II x4 920 @ 3.29 gigs
Gigabyte Ga785gm-us2h mobo
2 gb ddr2 800 mhz
Ati 4770
I want to reach 3.5 gigs.. i'm confused with the voltage to set.
with the stock VID, ie 1.35 v, i was able to reach 3.5 but after 15 mins, my pc restarted and wouldn't boot again(it showed starting windows 7 and then rebooted). What's the difference between CPU NB and CPU VID....? Should i increase both or just VID? How much should i raise?
In my BIOS, it shows +0.25, +0.5 likewise, pls tell me the value. Thanks in advance
 

xxenergyxx

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Well, if you read any of the guides regarding Overclocking Phenom II's on either this site (4ryan6's guide) or the guides on overclock.net,

You will read that you should Raise your multiplier first (which you did), and do that until you cannot boot into Windows or you FAIL prime95 stability testing.

So, you are saying you have already hit a wall.

This is where, if you read the other guides, you either continue to raise your Vcore to accomadate the higher Clockrate (3.5ghz you stated).

BUT, you HAVE to know your CPU's limit voltage, you don't want to go over this, as you can damage your CPU. Now for my CPU (Phenom II x4 965 C3) it is noted to be 1.55V.

At the same time, monitor your temps, even if you run STABLE with 3.5ghz at a certain CPU voltage, it doesn't mean anything if your temps are TOO HIGH, as you will again, damage your CPU.

First of all, do you have a CPU cooler bro? Or are you using the stock AMD heatsink?

Second, YES, there is a difference between CPU NB and CPU VID. CPU VID is the CPU voltage.

You don't have to worry about CPU NB now; or really at all if you are just going for a stable, 24/7 overclock you want to use day by day without really taking the life out of your CPU.

So if your at 3.5ghz with 1.35 CPU voltage (stock) and you crashed. THEN, logically, you are NOT stable. You need to raise your CPU voltage by the SMALLEST increment in BIOS, for me its .0125.

So My cpu is stock 1.4000 CPU volts, so if I increase it, I go to 1.4125 (0.0125 smallest increment).

AGAIN, know what your CPU voltage limit is, if you keep raising Ghz and keep raising CPU voltage without knowing your limit, you will fry your damn CPU.

The information for you is here http://products.amd.com/en-us/DesktopCPUResult.aspx

You want to find just the minimum amount of voltage to run your 3.5ghz. So it's trial and error.

I don't know what else I can say, but you should find more on the "sticky guides" here at this site, or even at overclock.net

Good luck my friend.
 

rajiv babu

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I have a Cooler Master Hyper Tx3 cooler..........
Actualy, mine isn't a Black Edition CPU. I increased the FSB to 235...thz all.
In the link you provided, i saw the VID max as 1.5 v
So, will i be able to reach 3.5?
 

xxenergyxx

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Oh sorry. I was under the impression you had a 955 Black Edition C3 for a moment.

I don't think that is the max VID on that site. It just shows the max temperature and the operating VID's.

965 is listed as Voltages 0.825-1.40V, but I believe AMD list it as 1.55max.

BTW, I don't know if you can hit 3.5ghz stable. It's trial and error and every chip is different. If someone tells you otherwise, its rubbish. You have raise intergers, then boot into windows and run stability test to see if your stable.

Read these guides if you haven't already http://www.overclock.net/amd-general/525113-phenom-ii-overclocking-guide.html

This one is awesome too, with videos http://www.overclock.net/amd-cpus/645456-need-help-learning-how-overclock-amd.html

That should help you alot man, the one with videos has a step by step guide for overclocking with FSB for non-black edition CPUS.

Let me know how that helps you, and you might want to try checking out overclock.net as it is specifically for overclocking. I'm down there as username XxAlbertoxX
 

rajiv babu

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Thanks for the links......... t....
So, how much do you think i can hit? maybe 3.4?
If i increase my cpu vlot to 1.425, will i be able to touch 3.5?
 

xxenergyxx

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Possibly. I'm not sure, I don't know that much about the 920 CPU.

Maybe, but watch out. when you increase voltage, your temps will go up, so make sure you monitor your temps and that you don't go over the max.
 

rajiv babu

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Wow! Those videos you provided were of great help to me....Thanks. Now, my 920 is running at 3.5 ghz, which is 25% oc according to OCCT. Thanks again.
But still, i got one more doubt. I had an 800 mhz ddr2 ram. But, as advised by the vids, i had to decrease 2 notch to be able to reach 3.5. So, now my ram is running @ 533 mhz. Will there be any performance differences? For my ram, there is a multiplier by the value 3.33x. So, it gives me 3.33 x 250 = 833 mhz. Can i clock my ram to 833?
 

xxenergyxx

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Awesome.

Well, you can try going higher for the RAM. You might get it unstable again though. The higher the RAM Frequency, the HIGHER The NorthBridge has to be. Ya know what? This explains it beautifully. This is the official guide for Overclocking by AMD.

http://game.amd.com/us-en/content/pdf/AMD_Dragon_AM3_AM2_Performance_Tuning_Guide.pdf

So if you read that, you will see, for example, DDR3 1600Mhz RAM, which is actually 800Mhz since DDR stands for Double-data-rate, so you double the number. So you multiple 800 times 3 = 2400Mhz. So thats what the Northbridge should be at for that RAM freq.

Read that guide, it's really awesome, it will explain everything you asked, about HT ref. clock and the RAM speed etc...

Let me know if you understand.
 

xxenergyxx

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Do you have AM2+ or AM3?

From the guide I'm reading, you should boost your HT Ref. clock above 250Mhz, and then you RAM speed will be your Ht. Ref clock speed, 250Mhz for example, multiplied by the RAM ratio, which for DDR2 800 is 2:1.

So 250 * 2/1 = 500Mhz

Thats how you figure out what the RAM frequency will run at when you overclock the HT. ref. clock, since it affects the whole system.

But read that guide, you will like it......
 

rajiv babu

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Thanks for the guide....
My 920 is AM2+...
Just one more doubt....... So, inorder to increase my ram speed, i will have to increase my fsb which inturn increases the clock speed of my processor, NB speed, Ram speed right?
So, inorder to increase only my RAM speed, i gotta decrease my CPU mulitiplier and NB multiplier right?
If i have to make my RAM speed to 800 Mhz, will i have to increase my fsb to 400 mhz? ie 400 x 2=800?
Wont it cause instability? Or, is there anyway to increase the RAM ratio?
 

xxenergyxx

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Yes, when you adjust the FSB or REF. CLOCK (what AMD calls it) , your RAM speed will increase. Also, your NB, since your NB is determind by the formula (HT ref. clock * NB multiplier = NB frequency) or 200 * 10 = 2000.00Mhz for the stock 965 Phenom II x4.

You don't have to guess at what any of these numbers will be when you adjust the HT ref. clock, because there all determined by mathematical formulas, it has the formulas on the guide I showed you from AMD.

So for example 210MHz HT ref. clock and DDR2-667 memclk mode will result in 350MHz (DDR2-700) memory clock
speed (210 x 5 / 3 = 350MHz)

I don't know if you can run your RAM at 800Mhz. That is the price you pay for overclocking your CPU using the FSB and achieving a higher clock rate.