FX-55 Based Super Computer

The following is a photo journal of a not-so-standar computer built for one of my better clients a while ago. He requested a system that would go beyond the stock hardware available at the time. The system was based on the then top-of-the-line AMD FX-55. The processor would be cooled to sub-zero temperatures and overclocked as far as it would go.

The cooling is accomplished by a Vapochill XE II case. It has a built in evaporative cooling system that will take the CPU into negative temperatures. Asetek's companion Waterchill system was used to cool the north bridge and the GPU.

The MSI K8N Neo4 Platinum motherboard was used as the base of the system. It was chosen for it's performance, reliability, and feature set. Here you can see the north bridge cooler and the ram installed.

Because the ram would prove to be a major factor in the overclocking, we went with the very fast OCZ Gold Limited Edition, PC 4400, 1 Gb dual channel kit. It is rated at 2.5-4-4-8.

During the construction, it didn't take too long before we hit our first snag. The 120mm radiator and it's fan needed a place to be mounted. I had wrongfully assumed that because I was using an integrated case, and the manufacture's complimentary water cooling kit, that there would be a place to put it. Boy, was I wrong. The distributor recommended that the radiator unit be dangled out the back of the computer and warned that any cutting of the case would void the warranty. Needless to say, I ignored them. The front of the case has a vent and mounting holes for a 120mm fan but not enough room for the radiator. As you can see from the picture below, the solution was to cut off one of the hard drive rails. This was accomplished with a rotary tool and a cutting wheel. The face of the case must be removed to screw the radiator to the case. The end result is an ideal location to mount the radiator and enough space left over to mount two hard drives.

This is the northbrige water block and it is mounted at the end of the PCI-X slot. No choice here because we can't move the northbridge. Paying more attention to such details, when selecting the motherboard, may have saved some effort here. The video card will not be able to insert all the way because the water block is too high.

This was a little bit of a gamble. The solution was to grind down a corner of the water block with a rotary tool. Before I did this, I removed the screw completely and tested to see if it would leak. It didn't. As a matter of fact the O-ring didn't seem to decompress at all. The screw also had to be cut down so that it could be reinserted. You must be careful not to over tighten it because there isn't much acrylic left.

The end result is a tight fit. But it works, and that's all that counts. The picture below illustrates just how close of a fit it was. There is about a 1/2 mm between the edge of the video card and the top of the screw's head.

While installing the northbridge water block hoses, I noticed another small problem. Although it probably would have been fine, the hose was applying too much pressure on the capacitor. It had to be relocated.

I removed the capacitor, and using some new leeds, re-soldered it to the back side of the video card pcb. The only real concern with doing this was to keep the leeds relatively short and to respect the polarity of the capacitor. The stripe down the side of a can shaped capacitor usually indicates the negative pole. The capacitor was later insulated and glued on it's side to the card.

The GPU water block needed to be trimmed down to fit over a capacitor. Once again this was done with a handy rotary tool.

Not very much had to be cut away to make it fit. The screw mount was not affected by removing the required material.

The power supply became a big problem. As you can see in the picture below, you are forced to really contort the cooling head's harness to accommodate a standard power supply. The harness is stiff and contains pipes with liquid flowing in them. The ferrite ring had to be moved down the power supply cables just to make it fit. It was that close! Even then, I was very worried that the pipes may have been pinched off. Ultimately it worked, however I'm not sure how this one escaped the designers. Choosing a physically smaller power supply may help a little, but this type of system is more conducive to large one, do to it's power requirements.

Here you can see the final result. A real rat's nest of pipes and wires. The water cooling tubes had a tendency to pinch closed when bent. To avoid the problem they were all curved very gently. Temperature probes can be seen on the sides of the Western Digital Raptor 10k drives. The drives are arranged in a raid 0 array. The thermal probes are also mounted on the water blocks and in ambient air.

The compressor and the water cooling kit both required a male/female AC adapter. With one plugged into the other it makes for an awkward setup. There is no doubt that it works and is easy to setup, but it is really ugly. At this price point I would expect a more elegant solution. It's a very large case and it's too much to lose an extra six inches because of this type of arrangement.

This is the finished projected. It can't restart, it just hangs at the post if you do. You have to shutdown, remove the plug from the back, count to ten and then plug it back in. This seems to reset something and allow it to start up. It was more difficult than it should have been, but when all was said and done, it worked. The company should take a serious look at what they can do to make this case more adaptable to their own accessories.

The CPU got up to 3.1 GHz. That's 500 MHz over the stock speed. That represents a ~20% increase in performance.

The CPU ran at -28.2 degrees celsius. It would have been interesting to test the same CPU with a water cooling only setup. I have a feeling that not much would have changed.

UPDATE: The client has decided to upgrade to the AMD FX-57 processor in order to maintain his advantage. Speed is very important to his line of work, and is tied to his bottom line.

AMD ATHLON 64 FX-57 SPECIFICATIONS:

  • Frequency: 2.8GHz
  • Cache Sizes: 64KB L1 Data + 64KB L1 Instruction Cache / 1MB L2 Cache(Exclusive)
  • Memory Controller: Integrated 128-bit memory controller
  • HyperTransport Spec: 2GHz (2x 1000MHz / DDR)
  • Packaging: 939-pin organic micro-PGA
  • Fab location: AMD's Fab 30 wafer fabrication facility in Dresden, Germany
  • Process Technology: 90nm Silicon on Insulator
  • Transistor count: ~114 million
  • Die Size: ~115 mm2
  • Nominal Voltage: 1.35-1.40V
  • Max Thermal Power: 104 W

When overclocking it this time we got it as far up as 3511 Mhz. However, it wasn't perfectly stable and thus not good enough for a business application. When all was said and done it was rock solid at 3346 Mhz. A measurable improvement over the FX-55, but still an approximate 20% overclock.

FIN