# Attempting to OC



## kraze1994 (Feb 12, 2008)

I am wanting to OC my new CPU which I have bought. I have the AMD X4 920. I have been playing around in the bios a little bit and it seems if I change the multiplier up to 14 then up the front side bus to 247 with no voltage changes I can achieve around 3.4 steady and can pass 24 hours of prime 95 without going above 55C. I am new to over clocking and want to see if I can get a little more OC out of it and if I can doing it right. 

System specs!
Newegg.com - Suggested Products 
Amazon.com: Corsair Air Series A50 Performance CPU Cooler CAFA50: Electronics

4.0GB Dual-Channel DDR2 @ 494MHz (6-6-6-18)(800) don't know why that says 494MHz. I am sure I messed something in the bios up. 
Type	DDR2
Size	4096 MBytes
Channels #	Dual
DRAM Frequency	494.0 MHz
CAS# Latency (CL)	6 clocks
RAS# to CAS# Delay (tRCD)	6 clocks
RAS# Precharge (tRP)	6 clocks
Cycle Time (tRAS)	18 clocks
Bank Cycle Time (tRС)	24 clocks
Command Rate (CR)	2T

Gigabyte Technology Co., Ltd. GA-MA785GM-US2H (Socket M2)
GIGABYTE - Motherboard - Socket AM2+ - GA-MA785GM-US2H (rev. 1.0)

ATI 4860 1GB of GDDR5 

For the power supply I am running two actually. I currently have a Corsair 600 powering all of the computer components and I have an Antec 430 powering the video card. 

I am currently running 4 large fans that keep my system very cool. I have a 200mm intake and another 200mm intake on side panel. Then I have another 200mm as outtake at the top of my case along with a 120mm for the back of the case. 

Idle Temps:

CPU 34C
GPU 35C

Temps:

CPU 100% load for 24 hours 55C
GPU 100% load for several hours 50-58C


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## r00x (Feb 13, 2011)

Your RAM reads 494MHz because you raised your front side bus to 247MHz.

247MHz * 2 = 494MHz!

Remember any changes to the FSB will affect the frequencies of other devices in the system, typically your RAM, Hypertransport bus and CPU in AMD systems. These days it's common for your PCI/PCIE buses and other devices to be locked regardless of what FSB you choose.

This means before you push further you need to consider the hypertransport frequency and RAM frequency and consider lowering their ratios/multipliers such that they remain operating within specifications.

At 247MHz FSB, your Hypertransport bus will be at 2470MHz effective, while it's designed to run at 2000MHz. In my experience it gives out between 2.4-2.8GHz, so consider lowering the HTT multiplier a notch, this will bring it down to 1976MHz with the 247MHz base clock you're using.

For your RAM, if it's designed to run at 800MHz (200x4) then at 247x4 you're nearly at 1GHz, which is pushing it for stability. Knock that down a notch before continuing too.

Your arrangement for powering the system is... interesting  what's the exact Corsair model? I'd have thought it alone would be more than adequate for your system. I run a Corsair HX620W on an Intel Core-i5 system at frequencies as high as beyond 4GHz with twin overclocked Nvidia GTX 460s.


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## kraze1994 (Feb 12, 2008)

Kept the multiplier the same but lowered the front side bus down to 245.


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