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Considering to overclock amd athlon ii x4 640

Last response: in Overclocking
December 29, 2010 11:52:00 AM

Hello, I want to overclock my cpu. I have been in BIOS and see a performance tab with the following values:
Cpu Frequency :200mhz
MCP PCI Express:100mhz
CPU Voltage: default
Chipset voltage: default
Ht voltage: default
CPU/LDT Spread spectrum: 0.5% hershey kiss.
These are the optimal values by the way.

I know that FSB is what you increase. But am i meant to increase any voltages? the other options i get is +0.5v or 5v. (I forgot which one it showed)
My motherboard is a biostar n68s3+ nforce630a chipset.
My psu is a 400w unbranded one, and I think there is a another fan inside my case excluding the CPUs default fan.
Thank you.
a c 159 à CPUs
a c 292 K Overclocking
December 29, 2010 1:18:48 PM


Please, list all your rig specs.
December 29, 2010 4:12:12 PM

CPU: AMD Athlon ii x4 640
Ram: 4gb ddr3
Gfx Card: Sapphire ati5670 512mb
Mobo: biostar n68s3+
OS: Windows 7 ultimate 64bit
PSU: Evo labs 400w psu (forgot model name)
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a c 159 à CPUs
a c 292 K Overclocking
December 29, 2010 5:20:38 PM

What speed and specs has your RAM?
December 29, 2010 5:32:10 PM

bios says its 1333mhz
a c 159 à CPUs
a c 292 K Overclocking
December 29, 2010 5:52:09 PM

qasim1991 said:
bios says its 1333mhz

And what says on the sticker? What said when you bought it?
December 29, 2010 6:04:30 PM

Just checked cpu-z it says, Max bandwidth pc3-10700 (667mhz). Dual channeled, DC mode : unganged,
December 29, 2010 6:04:58 PM

and NB frequency 1607.3mhz
a c 159 à CPUs
a c 292 K Overclocking
December 29, 2010 6:08:18 PM

Can you provide the link of the RAM that you have? CPU-Z doesn't have the specs that I asking you.
December 29, 2010 6:10:15 PM

I cant find a link but manufacturer is Micron technology and part number is ITC. Its 2x 2gb ram
a c 159 à CPUs
a c 292 K Overclocking
December 29, 2010 6:17:56 PM


My RAM is Crucial DDR3-1600 with specs 8-8-8-24@1.65V, you RAM must have specifications like those, that's what I need to guide you in the overlock process.
December 29, 2010 6:22:40 PM

Ok my ram is micron technology 2 GB DDR3-1333 DDR3 SDRAM (9-9-9-24 @ 666 MHz) (8-8-8-22 @ 592 MHz) (7-7-7-19 @ 518 MHz) (6-6-6-16 @ 444 MHz)
January 3, 2011 4:08:05 PM

So anyone that can help me?
I know my BIOS is an AMI one if that helps. I really would like to overclock my cpu I have seen some nice gains in reviews. There is also an option under Performance tab called AMD Overclocking Configuration it showed more values which made me confused.
a c 159 à CPUs
a c 292 K Overclocking
January 3, 2011 4:28:46 PM

Sorry, holidays keeps me away of the forum.

Like your CPU isn't a BE and your RAM is 1333, we need slow down the RAM speed before overclock the CPU. The CPU that you have needs be overclocked with the FSB, but that also change the RAM speed, NB speed and HT speed. So, change your RAM to 533MHZ in the BIOS. Let me know if the rig can boot without problems.
January 3, 2011 4:43:26 PM

I went to memclock mode set it from auto to 800mhz, 800mhz is the lowest setting I can choose from. Internet explorer and steam was crashing, so im lucky to reply back. What do i do now?
a c 159 à CPUs
a c 292 K Overclocking
January 3, 2011 4:50:43 PM

Your BIOS should give your and options to select the DRAM Frequency, the lowest can't be 800MHz.
January 3, 2011 5:02:18 PM

Ok my bad, it was ddr3-800 i had it on, but i found ddr3-1066 so i set it too ddr3-1066, and i double checked cpu-z and says Dram frequency is 533. Now what mate?
a c 159 à CPUs
a c 292 K Overclocking
January 3, 2011 5:05:18 PM

Now you need start to rise the Reference clock or FSB (Usually is 200MHz) in little steps and test the rig with prime95 or LinX (I prefer this) to check stability with those settings.
January 3, 2011 5:11:20 PM

Sure will do, I will let you know how it goes.
January 3, 2011 5:18:05 PM

I have set the FSB to 205 and it rebooted successfully, but when i raised it to 210 it wouldnt boot?
a c 159 à CPUs
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January 3, 2011 5:26:50 PM

Ok, maybe we need more voltage in the CPU. Before add more voltage, What cooler do you have?
January 3, 2011 6:25:21 PM

its called Super fan dc brushless, model: sdf8025m12s. Probs some aftermarket cooler or whatever lol. It blows directly on my cpu and temperatures are cool like around 21 degrees for my cores. i noticed i can change cpu voltage with 1 option +5v. CPU-Z states my core voltage is at 1.404v
January 3, 2011 6:26:13 PM

My HT link is 1000mhz (according to cpu-z)by default and 1025 with 205 fsb, in bios i can change ht voltage but i left it at defaultt
a c 159 à CPUs
a c 292 K Overclocking
January 3, 2011 6:45:23 PM

Add a little more voltage and try to rise the reference clock again. Always keep your eyes in the rig temps, you can use HWMonitor to check that.
January 3, 2011 7:05:01 PM

Ok so ill go to cpu voltage and choose the only option of +5V, ill let you know if my FSB goes higher and if it reboots correctly.
January 3, 2011 7:18:21 PM

FSB is at 210mhz now and i put cpu voltage on the +5v option. Temperatures have only increased by a few degrees. I'll reboot and see if it is just stable.
January 3, 2011 7:46:56 PM

Thanks for your time mate, but i give up, when i hit 210 fsb with cpu voltage increase programs such as steam dont work. I will just stick to default values.
June 10, 2011 9:03:04 AM

Not to re-open an old thread but that's an old chipset that's not even capable of doing 2000MHz HT, try upgrading to an AMD board with SB710 or SB750 if you want to overclock, I've got my Athlon II x4 640 at 3.8GHz at 1.55v and it's doing so idling 45 degree temps. Core temps are usually around 35 degrees, all this on stock heatsink/fan.

I know you probably bought the board because of it's low price, but there's some serious downsides to that low price.
Just thought I'd mention it because nobody else did.

AMD Athlon II x4 640 3.0GHz @3.8GHz -OC 1.55v
ASRock 880GM-LE AM3
G.SKILL Ripjaws Series 2x2 -4GB 1333 @7-7-7-21
Saphire Radeon HD 5830