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The AMD overclocking guide

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Emericana said:
(266mhz is the default DDR bandwith of AMD chips and by increasing the speed gives you higher and higher bandwith. As a quick reference point 166mhz FSB is 333mhz DDR and 200mhz FSB is 400 DDR)

266mhz is the standard ddr MEMORY SPEED of a current athlon platform (which is 133mhz*2)
the maximum BANDWIDTH with ddr266 is 2.1gb (which explains its pc2100 name)

so lets say you increase the fsb to 166mhz, which is ddr333 speed (166mhz*2). that gives you 2.7gb maximum bandwidth (pc2700)

with ddr400 (200mhz*2) you get 3.2gb maximum bandwitdh (pc3200)

of course this is maximum bandwith,which you will never get. but if your lucky you should get around 90 to 95%

so if your very lucky you should see aroung 3gb with ddr400, as apposed to 1.95gb for ddr266 so you can see the benifit of increasing the ram speed

remember though, this only applies when you increase the cpu speed aswell.
If you have ddr400 running at 200mhz fsb and your processor running at 133mhz fsb, your processor becomes a bottleneck and you wont see any benifit from your increased memory speed
and you should still ammend the part about the cpu voltage. i can get a 130mhz increase in processor speed running on 1.73volts which is BELOW standard voltage
Quote: james.miller

"The worst athlon XP stepping is AGKGA."

My 1700+ AGKGA will run at 1760 on 1.85 (160 x 11). A 300MHz o'c isn't what I would classify as terrible. This is on a 8KHA+ (unofficial BIOS -2314-). I feel that the chip will do higher, but I'm limited on the FSB. 160.00 FSB is maxed. 160.03 MHz and it crashes. Not a memory problem- I have Corsair XMS 2400 in it. I tried using the 8KHAL00.bin BIOS and couldn't get over 149 FSB!!?? I even set the memory timings according to Mushkin's guide over at amdmb.com. It's just not right having a 8KHA+ that I can't get to do over 160 on the FSB!! Not right I tell you...makes me feel naked. Not giving up though....surely that 8KHAL00 BIOS has to work for me. Sorry to get off topic, but I had to vent...off to go :beer: my 8KHA+ problems away....

-PM me if you can tell me more about the 8KHAL00 BIOS...

yeah the 8KHAL00 is an older BIOS, but it boasts the highest FSB speeds....the 8KHA+ was one of the first KT266a boards to break the 200 MHz FSB "barrier" with this BIOS- as you may already know. Everyone has had great experiances with this BIOS. Not me. Plagued. Thanks for the link, but this was the guide I was talking about earlier....great guide, just still hasn't help me figure out why 8KHAL00 turned out to be a dud. With this BIOS I ALWAYS had to clear the CMOS after a restart and then set my settings back up in the BIOS. I then set my timing from 2.5T to 2T, and it fixed that prob- but anything over 149 on the FSB wasn't a go. Maybe I'll have someone lock me in this room, and not come out until I've got it working....

Thats a lot better, it could be bettered slightly but that will come with time ;)
The things wrong are:

  1. Using fans, you say that a 50CFM+ fan yields a 200Mhz+ overclock....wrong. Some people using WaterCooling and a Volt-Mod couldn't overclock more than 50Mhz, its the chip and Motherboard, not the fan although it does help (you should mention all this, remember my recent Variation talk)
  2. Also the AS grease, using too much won't fry your CPU. It just won't be cooled so efficiently, and AS3 removes itself from the CPU die if theres too much, hence why so many people have found it dripping to the side of their Core :eek:

    There are many more but I think you can work them out.

    BTW To save you the hassle you've got permission to link my Tweaks-The Definitive Guide in your guide, as it covers all the Tweaks people thought you may wish to add to your Guide.
    Lastly you will get emails from 'New members' asking advice, please if you aren't sure let either Me, or another Senior/Mod help you out, the last thing you want to do is mis-inform someone.

    Keep up the Good Work, :)
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Spec_Ops2087 said:

Nice guide man:clap:

This should may be a stickie...where are mods when you need them?!


LOL....this Mod got commissioned by a co-worker to build a 'puter for his kids the other day, for "back to school". I've been setting that up, and installing the OS/apps.....;)

Sorry for the delay, M_N...yeah, we'll "stick" this one for a bit...:cool:

Here is something i wrote up about the PSU and was going to put it in the main message but it exceeded 20,000 characters.....

One of the most important things that is usually the most overlooked to have in a great overclocking rig is your Power Supply Unit (PSU). The absolue minimum voltage for a power supply is 300w. However, it is recommended, if you can afford it, to purchase a 400w one just to be safe. Now, you just do not want to get a powersupply because of how many devices you run in your system (that is, unless you are not overclocking). Buying a quality high wattage psu ensures that your +5 and +12v lines are where they should be. (at 5.00v and 12.00v). I honestly do not know too much about what these voltage lines do (maybe somebody else can explain it further down in this post) but I know that having the lines too low (around 4.8v) or too high (around 5.1v) is bad for your system and can cause unstability in the form of random reboots. That said, the minimum size powersupply recomended to get is 350w if you are building a overclocking rig. The absolute best powersupply brand isPc Power and Cooling but these guys are EXPENSIVE as hell. because of this, i recommend that you purchase either a Enermax or Antec PSU (i personally use the Antec 400w) because they are great quality at a somewhat reasonable price. A common symptom of a powersupply that is not up to standards is that if you have to hit the restart button multiple times to get your system to POST (show the bios screen) after trying to overclock your system. Also, random lockups for no reason (this is only a symptom if you are SURE your PSU is to blame and have allready tried the cpu ram and mobo). You can either check your +5 and +12 voltages through bios or by using software programs such as Motherboard monitor or whatever came with your board (such as abit hardware doctor). Personally, at 1.95v, my +5v rail is at 4.92 and my +12v is at 12.00 flat. Increasing the voltage (discussed later in depth) makes your +5v and +12v lines go DOWN so that is why it is a great reason to get a good PSU to begin with.
That is why I dont particularily like Epox mobos even though the 8kha+ was a great motherboard. Epox leaves out essential features on their boards and many of them are very buggy, especially the 8k3a. I know that on there Pentium 4 boards they dont even include a +12v connector which makes a big psu essential. I have a vmod on my board and it works great with a 400w PSU, however, i also do not have that many i/o devices, only sound card/nic/dvd/cdrw/floppy.
I've found there boards to be very 'bugless' :p and always top on the feature's list, my overclockers favourite.

However with there very competitive pricing who couldn't expect a few minor hickups :D

Ahh this is a wonderful guide. I guess that last note on PSU confirmed why I can't OC much on my PC before it crashes...only 300 watts and a lot of major hardware in ma baby.
thanks for writing it out:)
problems in overclocking

well i have a duron 800 machine with ASUS A7V133-VM and i am desperate to overclock it to 1Gig. as it can't be done through fsb i tried to unlock the cpu with a 0.5 mm pencil, carefully, so that the lines do not overlap. but nothing happened. i still do not find any field in the BIOS through which i can change the multiplier or voltage settings. so it has become impossible to me to change these settings as my motherboard does not have any jumpers or DIP switches either.
i don't know if i have done anything wrong while connecting the L1 bridges. does my motherboard actually support changing the multiplier settings?
can the L3,L4,L7 bridges be joined in similar fashion to change the voltage or multiplier settings? how can i cut the joined bridges?
can anybody help me please.
thank you.

you need to manually adjust jumpers to change the mults on your bios :(

that is if it is indeed unlocked. i think it is much easier to unlock it with either conductive ink or trace tape than with a pencil mainly because with a pencil it takes time after time after time till you finally can get it right
the saddest part is the m/b does not have any jumpers to change multiplier or voltage, so my only option, other than tweaking the m/b, is to do it through the BIOS, which does not show any info regarding these settings presently. will the BIOS show any field if i manage to unlock the cpu successfully ?
anyway thanks for your resonse.