So you want to snag top score on the MadOnion board, eh? What do you suppose that takes? You'd be surprised at the lengths these fellows go to in the interests of a little friendly competition. These machines are one-of-a-kind Road Warriors, intended purely for competition. It would be impossible to really live with one for any length of time. They're like engineering breadboard projects: barely held together with chewing gum and baling wire. But their performance levels are glorious!
Let's check out some of these wonders and see what it takes...
You won't get far overclocking with a lame motherboard. You want a board that supports all the cool overclock options, preferably in BIOS, since you will tinker a lot with those options and jumpers slow you down. Also, you are going to need room around the CPU for a really potent cooling system, so your board must avoid putting too many capacitors, connectors, or other obstacles near the CPU. The Abit KR7A is one of the hot overclock mobos. It lets you fiddle with endless options to do with voltages to various chips (more voltage = higher speed right up until you fry the chip), clock speeds, and various odd little options that all add up.
Just a few of the many overclocking options available via SoftMenu III BIOS on the Abit KR7A
The CPU chip makers are no dummies--if you overclock a chip too far the system becomes unstable, leading to lots of support calls. You have to actually modify your CPU chip to get maximum overclocking. Whoa! How am I gonna modify my chip? No problem. There are these things called bridges that are sorta like jumpers. Chip makers use them to make their manufacturing process cheaper. The same chip core is on most of the versions, and these jumpers set what clock speed and in some cases other features like multiprocessing may be used. Your mission, as a Radical Overclocker, is to unlock these jumpers. This is a frightening process, as you paid $200 for the chip, and what you are about to do places the chip at dire risk while voiding your warranty.
Unlocking these chips is sort of an arms race. First, AMD doesn't publish specs on it, so you have to find the info on the web. On earlier chips, you could literal use a pencil to lay down conductive graphite and unlock the chip. That was too easy, so AMD fiddled the electronics so that pencil graphite wasn't conductive enough to work. So the overclockers used conductive paint. With the latest XP chips, AMD used a laser to cut a groove between the bridge contacts. Conductive paint would fill the groove and short all the contacts together, rendering the chip useless. So, Radical Overclockers have learned to fill the groove with epoxy before applying their conductive paint. I'm sure AMD will think of something more extreme in their next round of chips. Meanwhile, our hapless overclockers have to risk chip and pocketbook while working with jeweler's loops and pins as paintbrushes. Be careful, those contacts are small!
Those little dots are the bridges, and you better know which is which!
Voltage Mods: Captain, I don't know how much longer she'll take it!
Okay, we've got the sweet mobo. We've unlocked our CPU chip. We've cranked every imaginable parameter to its fullest. Each time we tinkered with a parameter, we dutifully ran our benchmarks to see what we'd gained and whether the system was stable. Eventually, we have found that point where increasing any of the parameters even a little bit leads to crashes, blue screens of death, and other unpleasant side effects. BUT WE STILL WANT TO GO FASTER!
Fear not, young Jedi. You've hardly begun your training. Now you're ready for the real Radical Overclocking secrets. It's all about voltage. The more juice you give these chips, the more they stabilize at higher speeds. That is, right up until you manage to fry the chip. So be careful!
In fairness, you are not completely unfamiliar with this principle. Your mobo allowed you to raise the voltage on the CPU, for example. But it only goes to 1.8V. That's still very much in the safety zone, so you're unlikely to toast the chip unless your cooling is way under par. Unfortunately, the real masters of the MadOnion 3DMark are way beyond 1.8V. How did they get there? With custom voltage mods!
And by the way, they didn't just mod the CPU voltage, they're juicing every chip in sight. The graphics card, the RAM, the mobo Northbridge, and the CPU all get a little jolt from our electrodes.
Custom Juicer: Potentiometer taped to board with connection to a fan outlet.
The potentiometer let's us adjust voltage as high as we dare--up to 5V!
Cooling It Off: She's burning up and I can't change the laws of physics!
Of course the trouble with cranking the voltage is it cranks the heat. Left unchecked, we will fry our precious CPU, graphics card, RAM, and mobo, since we're cranking them all up, we gotta cool them all back down if we hope to live to tell the story. Many strategies have been tried. Water cooling is too tame. We need something more aggressive. Peltier cooling devices, phase change refrigeration systems, dry ice, and even liquid nitrogen are all fair game and work to greater or lesser degrees.
How about using 6 pelts and 3 water blocks to make a water chiller? -2C to -4C temps...
That chiller supplies this. Note pots everywhere for vmod. System uses 3 power supplies for juice...
You gotta insulate the tubing to keep condensation and temps down...
Another Peltier chiller...
Installed in a cube case! Ran down to about 1C...
This system uses dry ice piled in strategic places to cool. Not practical for long sessions but at least it won't short anything!
Note the massive chilled water cooler clamped to the Video Card...
Around back of same system we see the CPU cooler...
A custom fabricated RAM cooling system...
Then there's the liquid nitrogen club. LN2 on CPU and Radeon 9700 GPU.
The LN2 boys are Finns, and they blew past the 20K mark with this rig!
All material © 2001-2006, Robert W. Warfield.