Overclocking the A7N8X for Newbies

[Nerbil]

Overclocking the A7N8X for Newbies

Things to Remember:

Before even thinking of overclocking - you must thoroughly read the stickied A7N8X FAQ. From this point on, I am assuming that you are familiar with this FAQ and therefore I will not re-explain the information contained therein, unless specifically required. Failure to read the FAQ before posting on this forum is strongly discouraged.


• Overclocking is Work! Fun, but still work. It takes time and patience - this means taking it slowly and benchmarking and testing for stability at every step.
  
• Overclocking can be Hazardous! The chance of physically damaging a component is slight, especially if you heed the rule above. Here is an excellent explaination by Loibisch on the Dangers of OCing your CPU.
  
  However, it is a known issue that the A7N8X will randomly experience "BIOS Death" when exiting BIOS. Here's a list of ways to recover from BIOS Death.
  
  As was once said on the forums, there's alot of "techno voodoo" concerning BIOS Death - here are a couple, take from them what you will.
  
  
  • When exiting BIOS, some prefer to "Save Changes" and then "Exit and Save," waiting a couple fo seconds before entering each command.
  • If you exit BIOS and the machine rewards you with a black screen and no POST, do not hit reset. Unplugging the PC in the back has never steered me wrong.
  • Removing all components from the motherboard (please disconnect the PSU ) and sitting it on a sheet of tin foil for a while has been known to resurrect a dead board.
• No two components are alike! Many first-time OCers simply want "magic numbers" to enter into BIOS. Unfortunately, just because someone has the same chip/memory/mobo that you have doesn't mjean it will OC the same. To find the best settings for your system, you're going to have to put in some effort.
  
• Become familiar with resetting CMOS! Odds are that you will need to do this at some point in your OCing process. Don't be afraid of it. Here's some CMOS Clearing suggestions to get you started.
  
• Research your Components! This will help a whole lot in the long run. If you need to find out exactly WHAT kind of CPU you have, you reference the numbers found on the chip. Here's a link to the AMD CPU Stepping Decoder.
  
  You can also find out the optimal factory recommended memory timings by visiting the manufacturer's website, in most cases. Googling the serial numbers on the memory module chips can also lead you in the right direction.

BIOS Terms Simplified and their Signifigance to Overclocking:

All these settings are found in Advanced Chipset Features

Front Side Bus (FSB): This is the spead at which the CPU communicates with the memory. This is the most important element to OCing the A7N8X.

CPU External Frequency: This is the FSB speed that the CPU operates. This frequency is doubled when referring to the CPU. For example, the Athlon 3200+ is a 400mhz chip, which means it operates at 200mhz FSB. Any future mention of FSB is referring to this setting.

CPU Frequency Multiple: Commonly referred to as the "Multiplier," this number is multiplied by the FSB to equal the CPU Clock Speed. For example, A 133mhz FSB CPU with a multiplier of 15 runs at 1995mhz. (Multiplier * FSB = Clock Speed)

Memory Frequency: Specifies the FSB frequency of the memory. Like the CPU, the FSB is doubled when referring to memory - for example, DDR400/PC3200 Memory operates at 200fsb.


This setting is the key to overclocking - this must be set at 100%. By doing so, the CPU and Memory are communicating in sync with each other, improving performance and stability.
CPU vCore: This controls the amount of voltage supplied to the CPU. In order for the processor to run at faster speeds, the vCore often needs to be increased. Here's a list of Stock Voltages, Multipliers and FSB's of AMD CPU's.


Warning! Voltage = Heat! When adjusting the vCore, do it 1 increment at a time, and keep a close eye on your CPU Diode temps. Increased voltage will also shorten the life of any component - usually this means that instead of lasting 20 years, the chip might die in 5 - 10 years. Overclock at your own risk.
DDR Reference Voltage (vDimm): Similar to vCore, except this controls Memory voltage. When running the Memory FSB faster than specification, often times vDimm needs to be increased to give the memory an extra boost.

Memory Timing: These vary depending on your specific memory - always consult the manufacturer's website on the optimal settings. Often times, as the FSB goes up, these need to be "relaxed" by raising values. Here's a detailed Explaination of Memory Timings. You can start with an "Agressive" setting, but if the timings need to be manually adjusted, set this to "User Defined".

System Performance:Set this to "User Definied" in order to access all fsb settings beyond the default 100,133,166,200.

CPU Interface: Set this to "Aggressive" for fastest performance or "Optimal" for more stable performance.

AGP Voltage: This has very little impact to OCing - if experiencing Video problems, you can try raising this - but it usually makes no difference.

AGP Frequency: Leave this at Auto or 66mhz

Chip Voltage (Uber BIOS Only): This setting has no effect whatsoever on either Rev 1.0x or 2.0 boards. It is a null setting that is not implemented.

Proper Overclocking Conditions and Obstacles

• CPU Cooling: Making the processor run faster means it is going to generate more heat. The stock AMD heatsink/fan (HSF) is not sufficient to safely cool an OCed CPU. Here's a comparison chart of all the latest heatsink's available. For OCing purposes, I would suggest a HS that scored a .30 or lower on the C/W scale. Each heatsink listed also links to its review.
  
  While you're investing in proper cooling, you might as well seal the deal with Arctic Silver Thermal Compound (and instructions on how to apply AS3). Sufficient case airflow is also a good idea.
  
  You also will need to be able to properly monitor your temps. For this, use Motherboard Monitor. Everything you need to know about monitoring the A7N8X can be found in the MBM FAQ found on the forum.
  
• Chipset Cooling: This is not always necessary. However on some of the earlier boards (and even some Rev 2.0's) the Northbridge Heatsink suffers from a concave base - meaning it is not making proper contact with the NB. When the NB gets too hot, it makes higher FSBs unstable and will also cause 3D Application crashes, since the AGP is controlled through the Northbridge. This can be solved by lapping the heatsink and reattaching it with some AS3.
  
• Memory Requirements: Due to the fact that OCing relies heavily on the Memory Frequency staying in sync with the CPU FSB, it is best to have at least PC3200 (DDR400) memory so that a FSB setting of 200mhz will run it at its optimum speed. PC2700 (DDR333) operates at 166mhz FSB - limiting how high you can raise the FSB. Alot of PC2700 sticks will overclock to 200mhz with relaxed timings and increased voltage.
  
  And of course you've been lurking in the forums, so by now you know that this motherboard tends to be rather picky with RAM, so compatible quality Memory is suggested (but not necessary) to maintain a stable overclock.
  
• Revision 1.0x vs 2.0: The fact of the matter is that Rev 1.0x boards have a harder time reaching 200fsb compared to the 2.0. This is a result of a lower VDD voltage being supplied to the chipset. If the higher FSBs are simply unobtainable, your only solution may be MarginJohn's VDD Volt Mod. It looks daunting, but has a very high success rate, increasing FSB capacity to sometimes above 215mhz. If you have a 1.0x revision board, BIOS version 1004 will help achieve higher FSBs.
  
• Adequate Power Supply: A clean source of power is necessary - not only for overclocking, but a stable system in general. Do not skimp on your Power Supply (PSU). A 500W PSU for $50 sounds like a deal too good to be true - and it is. The most important factor in a PSU for the A7N8X is the +12v rail. You can get a better understanding of what PSU your system requires by reading this article on Estimating your PSU Needs by FiringSquad.com. A PSU that supplies at least 15a on the +12v rail is STRONGLY suggested. 18a or higher is recommended. The Antec and Enermax brand PSU's are tried and true around these forums.
  
• Locked Lower Multipliers: The A7N8X sometimes does not "unlock" the full range of multipliers for Athlon CPUs. As you will see later, the lower multipliers are important to OCing, so this can be a problem. CPU's with a Thoroughbred or Barton core can be easily unlocked by performing the Wire Trick. Unlocking a Palomino Core CPU is still possible, but not quite as easy. Got a T-bird? You can join in on the unlocking madness and Unlock your Thunderbird CPU too.

Overclocking Tools and Utilities

Pencil and Paper: I can't stress enough how important it is to keep track of settings and benchmarks along the way. Make yourself a chart - take note of bench scores, FSB/Multi combo, memory and voltage settings. Lazy? Download this Printable OCing/Benchmark Chart (thanks CamLopey!). You'll be glad you did.

Motherboard Monitor 5: An ingenious program by Alex Van Kaam, this is a vast improvement over AsusProbe. Visit the MBM FAQ for info about temp monitoring, what temperatures are safe, and auto-config files for the A7N8X. No overclocker should go without this utility!

Prime95: This program is often used to stress your system (to determine max "load" temperatures), and is extremely useful in testing for stability. This program will be discussed in more detail later in this guide.

WCPUID: This program will give you important information about how your Processor is running. It will report CPU Frequency, Clock Speed, Memory Frequency, and other vital information to overclocking.

Benchmarking Tools: How can you be sure you're making your system better if you don't benchmark it? Here are links to what most of us use:
3DMark 2001 & 3DMark03: These two programs will test your 3D Rendering capability - 3DMark03 will only work if DirectX 9.0 is installed.

PCMark 2002: This will test your Processor and Memory and give you a score to compare, just like 3DMark.

SiSoft Sandra 2003: This is an all around Benchmarking/Diagnostic program that will give you detailed information about your system. The important benchmarks here are Memory Bandwidth, CPU Arithmetic, and CPU Multimedia.

HDTach & ATTO: These are good Hard Drive Benchmarking tools - the Sandra and PCMark HD results tend to be unstrustworthy. The ATTO download is listed as "Windows SCSI Utility" but it works fine with IDE drives.

MemTest86: Not really a benchmark program, but this DOS based util is valuable if you suspect your memory of being faulty. This program will test for memory errors.

Overclocking: Step by Step

The following guide is assuming that your Memory Frequency is set to 100%, you have PC3200 or greater memory (PC2700 will overclock similarly, you will be limited by how well your memory can overclock past 166mhz), and that you have a 266/333mhz (133/166fsb) Processor.

1. Bench your System: Now would be a good time to get a "baseline" benchmark of your system. Use the programs listed above.
   
2. Lower Multiplier: Keeping in mind that Multiplier * FSB = Clock Speed, lower the multiplier to 9.5 or lower. (Try to stay away from 10 and 10.5, they mysteriously don't always work, but do for most)
   
3. Raise FSB: If you have a 133fsb CPU, start with 166fsb. If you've already reached 166, or have a 166fsb CPU, continue upwards in 5-10mhz increments. Save and Exit BIOS.
   
4. If...:
   • Your system POSTs and boots to your OS without incident, continue on with the next step.
     
   • Your system fails to POST, turn off the PC and restart it. If it then POSTs, go into BIOS, re-make the previous changes to FSB and Multiplier, and increase the vCore and vDimm voltages by one increment. If your system does not make it into Windows, continue upping vCore until you have gone .10v over the stock voltage (if this is the first time on this step) - keep an eye on your CPU temps! If your system still fails to make it to Windows, you may need to manually adjust Memory Timings and/or lower the FSB until resolved.
     
   • Your system fails to POST but does not restart after powering down, you need to clear the CMOS. After performing the clear, go to the previous condition above.
     
   • Your system POSTs but you get a Blue Screen (BSOD) while loading Windows, re-enter BIOS and raise the vCore an increment or two until Windows loads. Keep an eye on your CPU temps in BIOS.
5. Benchmark/Stress: After every signifigant setting change, you should bench your system and record your scores. This is why patience is necessary! Get used to hours and hours of Benching/Stressing! You can test the stability of your system by running Prime95's torture test. If your system cannot pass several hours of Prime95, that means:
   • You need to raise vCore and/or vDimm voltages
     
   • You need to relax/tune your memory timings
     
   • You have reached the max clock (or "hit the wall") of your CPU
     
   • Your CPU is running hot, causing instability
     
   • Your Northbridge could be overheating, causing instability
     
   • You have reached the max FSB for the motherboard/memory/CPU
   Two to six hours of error-free Prime95 is probably sufficiently stable. If you are a stickler for stability, 8-24 hours is recommended (I've had errors past the 24 hour mark).
   
   If you are experiencing 3DMark crashes with higher fsb's, this is most likely caused by the Northbridge getting too hot or insufficient VDD voltage to the Chipset. You can also try upping the AGP Voltage and turning off Fastwrites/8xAGP in BIOS.
   
6. Repeat: If you are satisfied with the level of stability and performance after stress tests and benchmarking, repeat steps 2 through 5. Once you have discovered your stable FSB limit (while keeping the Multiplier low), lock your FSB where it is and start raising your Multiplier by using the Bench/Stress method above - keep an eye on your temps! They will increase substantially as your increase your Multiplier.
   
7. Fine Tune: Once you have settled on your Multiplier and FSB, you can fine tune the rest of your components. Experiment with different memory timings to see how tight you can get it - but like before, take it in small increments. Also double check that you haven't over-compensated your voltage levels - there is no reason to have them higher than necessary.

FAQs, Guides, and Lists

A7N8X FAQ
Agent Smith's Auto-BIOS Flash Recovery Method
Arctic Silver 3 Product Instructions
CPU Stepping Decoder
Athlon CPU Stock FSB, Multiplier, and Voltage List
BIOS Death Recovery (Hotswapping) Tutorial
Clean BIOS Flashing for Newbies
Dangers of OCing your CPU
Demoulous' UberBIOS ReadMe
Easy HAL Mode (ACPI/APIC/PIC) Switch
FiringSquad.com's PSU Requirement Article
Fix for Stuttering Graphics with Catalyst Drivers
Fix for "Bad Checksum Error" Loop on POST
Heatsink Roundup
Memory Timings Explained
MJ's Heatsink Lapping Tutorial
MJ's VDD Volt Mod
Motherboard Monitor 5 (MBM) FAQ
Sensor Pic - Motherboard/Case
Sensor Pic - Socket
Tweak Town's AMD Overclocking Guide
Unlocking Multipliers - Thoroughbred/Barton Cores
Unlocking Multipliers - Palomino Core
Unlocking Multipliers - Thunderbird Cores
WindowsXP SP1 nVidia Driver Slipstream Tutorial

Download Links

3DMark2001, 3DMark03, and PCMark2002
ATTO HardDrive Benchmark
HD Tach Benchmark
MemTest86Motherboard Monitor 5
Prime95
SiSoft Sandra 2003
WCPUID

To be continued...

[Jimbob0i0]

This has been added to teh tutorial sticky.

[AMDScooter]

Sticky...yecch

[wolfmanstout]

So far, great job! The newbies just got a whole lot luckier

[wolfmanstout]

You also might want to mention under the "overclocking can be hazardous" section that overclocking has been known to corrupt files (eg registry, I know all too well ). In fact, you might even want to link to the guide to recovering the windows XP registry (http://support.microsoft.com/?kbid=307545). I at least wish I had known about that guide before I installed the second copy of windows.

Another thing to mention about voltages in general is that no matter how low your temps are, a high voltage (eg. 2V vcore) WILL shorten the life of components (this is due to the fact that more power is being pushed through the processor, high temp or not).

I won't be offended or anything if you don't include these suggestions; I'm just throwing em out there.

Thanks,
wolfmanstout

[LSD_US3R]

What about a def for dual and single channel mode, I know n00bs will ask for this. Great work till know, like always.

[Rising Force]

Great job Nerbil,

I think that you should mention in the beginning of the guide the importance of having enough cooling capacity, since it will greatly affect the stability of the system and can thus determine your maximum O/C.

Also, include a small section where you explain "what we are aiming for and why" e.g. 200MHz FSB for running PC3200 memory in sync. etc. There are a lot of newbies out there who still thinks that 15x133 is better than 10x200 for a system with e.g. PC3200 memory. I think that it is time to give them a hint or two! There are way too many out there!

We'll back you up in case you need assistance.

/RF

[DigitalRuin]

Good job Nerbs!! Hopefully though it doesn't remain a sticky in the Tutorials section when it's all done because then the noobs will NEVER find it. They don't look in the stickies to begin with.

[Nerbil]

Great job Nerbil,

I think that you should mention in the beginning of the guide the importance of having enough cooling capacity, since it will greatly affect the stability of the system and can thus determine your maximum O/C.

Also, include a small section where you explain "what we are aiming for and why" e.g. 200MHz FSB for running PC3200 memory in sync. etc. There are a lot of newbies out there who still thinks that 15x133 is better than 10x200 for a system with e.g. PC3200 memory. I think that it is time to give them a hint or two! There are way too many out there!

We'll back you up in case you need assistance.

/RF

All that stuff is on the way, I swear. Its already getting kinda long tho - and I haven't even gotten to the heart of the matter...

[BIM2k]

Good job Nerbs!! Hopefully though it doesn't remain a sticky in the Tutorials section when it's all done because then the noobs will NEVER find it. They don't look in the stickies to begin with.

it's true. we need a better way to attract their attention to those threads