Trapped under ICE: Extreme FX-55 overclocking

Overclocking/Overclocking Tests by charlie @ 2005-02-03

When you have the fastest CPU (at stock speeds) on the planet, you just have to push it further, although phase change cooling can get your underway, LN2 is bound to give you the edge. Let?s pour a few litres on this blazingly fast A64 FX-55 to see how high it can fly.

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OC fun...

Now it is getting a bit colder and I started the machine, the temp readout was at -60°C at this point, good single phase change territory. Went into Windows and pulled off a 3450 MHz OC, easy as pie.

Madshrimps (c) Madshrimps (c) Madshrimps (c)

About this time I hook up the fluid temperature probe and see our fluid temp is below zero, about -5°C. I keep pulling the temp down, into cascade territory :-). So I decide, OK let's go for screenshots and try to find the CPU's MAX. So here's 3500 MHz

Madshrimps (c) Madshrimps (c) Madshrimps (c)

Getting some seriously cold temps... way past the Cascade Phase-Change setups, easily blasted by 3600 MHz at -100°C, and this is IHS temperature, NOT the base temp!!

Madshrimps (c) Madshrimps (c) Madshrimps (c)

So there I am, with 3600 MHz under my belt. The plan is to find a ceiling and come back and run benches at the "sweet spot". The motherboard is starting to have some difficulties about -120°C.... Very bad cold-booting problems, could be the OCZ PSU, too.... they have a reputation for that kind of thing. But I managed to pull it down another 20°C or so.... and pull off 3700MHz+. By this time, the fluid temp is about -10C, just perfect for most motherboard components :-)

Madshrimps (c) Madshrimps (c) Madshrimps (c)

So after 3708 MHz, I pull her down to about -135°C and increase the vcore up to 1.92v, get into clockgen and slowly increase the speed, up and up.... 3730, 3760 and at 3796 MHz I get a BSOD. So immediately I knew it was all about vcore. I shut down the PC and upped Vcore to about 2.0v. I knew from experience that this would net me about 3830Mhz or so and THUS…THE WORLD RECORD!!! At any spot north of Memesama's 3828MHz.... I was sitting at about -140°C and hit the switch, nothing......

and then nothing....

and then nothing…

PC never booted up again. I thawed all out and checked the components.... the board would boot and spin the system and videocard's fan, but no video. The HSF got pretty warm....

I returned home and started testing the individual components; Videocard…OK, RAM…OK. So it's between the FX-55 (doubtful, as it warmed the HSF) the K8N Neo2 (probably) and the OCZ PSU. So that's it.... it's all I've got for you, didn't quite accomplish what I wanted to, but had a lot of FUN!

Lesson #1 from benching LN2 >>>>> Go for your highest best bench FIRST!! Just in case you kill something! Only had a chance to run 1 SuperPi benchmark at 3400 MHz and 24s.

Even had about 5 litres EXTRA LN2!!! After freezing just about everything at work, I even had to throw some away :-(

Madshrimps (c)


Just a side note: I've had the board standing on its side for 24 hours now, and it's still dripping!

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