Overclocking the Athlon 64 with PolarFLO



PolarFLO is a unique American water block builder in that they've decided to base their "product line" of H20 CPU-water blocks on just one unique design. Prior to PolarFLO's TT Series CPU water-cooler they offered their Universal CPU Waterblock SF which has been discontinued.

Both models feature a single inlet, dual outlet (with the option of capping one return) arrangement which can offer certain advantages based on system pressure and rate of flow. Water blocks utilizing dual outlets take better advantage of the impingement process as the water absorbs then dissipates heat from the processor more evenly and rapidly. This is of course dependent upon the flow rate, and pressure of the pump used.

Most triple barb designs locate the inlet directly over the impingement zone which should be centered over the CPU core (ideally). PolarFLO has eschewed any type of spray or manipulation of the incoming stream thereby eliminating additional back pressure. Below we take a much closer look at PolarFLO's impingement area/base plate.







PolarFLO’s choice of copper for base plate material is ideal given the cost and no corners are cut as the base plate is of substantial mass. Without expounding too deeply into a subject worthy of its own article, there are antithetical approaches to water block design where the mass and material of the block itself are concerned. In a copper water block built on the minimalist design, just a few mm of copper (the impingement zone) lay between coolant (incoming water) and heat source below (CPU). This design seems to be more prevalent among European water block manufacturers and is based on concentrating H20 at the heat-source then removing the heated water as rapidly as possible. Such designs will use inlets capable of creating specific water streams and impingement zones which concentrate water into a specific area. They are usually based on low flow systems are compact and most use 8/6mm hose.

The theory embraced by PolarFLO, TT in particular is a uniquely American engineering concept where greater flow rate (pressure) and material (mass) are required as the water block’s base plate plays a larger, more active role in the cooling process. Drawing from the 1st statement in the 2nd Law of Thermodynamics pertaining to heat transfer heat flows from hot to cold. Utilizing mass and material PolarFLO engineers gave their block substantial mass into which they've machined a series of channels creating a spoke pattern. Water entering the (center) inlet impacts upon a stanchion in the center of the impingement zone and is then forced along channels to an outer reservoir where the heated water exits via the outlets located above this outer channel. The design is both simple in its uniformity, yet complex in execution, nonetheless it's effective as were about to see.


Test Setup, Methodology and System Ergonomics

Test System
CPU	A64 3500+ Winchester .09-micron process
Mainboard	DFI LANparty NF4 Ultra-D (BIOS 310)
Memory	Corsairmicro XPert TWINX-1024MB CL2-2-2-5
Graphics	BFG 6800GT-OC (370/1000MHz GDDR3)
Power Supply	Thermaltake PureSilentPower 680
Cooling	PolarFLO TT (copper) Hydor L40-II (2800 LH / 230cm MAX-H) Danger Den Dbl Heater Core 2xSunon 120mm/90CFM (1/2”)
Operating System	Windows XP SP2

The topic of water-cooling test methods has been a point of contention among more out-spoken hardware sites. Some sites prefer a more scientific method (due to repeatability of results) and use a Simulated Die. The term "simulation" would seem to belie any sense of accuracy, however; the opposite is actually true. Most sites, however; use "Real World" results, unfortunately there are many variables in from one test environment to the next for any hope of definitive and repeatable results. Nonetheless I’ve chosen this age-old method, there are significant differences between the heat signature of a CPU and a simulated die, the former being a much more complex animal.

A final point of contention would be hardware placement. I decided to place the pump, Heater Core and reservoir outside my case. My reasoning being twofold, first for ease of accessibility to components and then to eliminate temperature differentials existing between room (ambient) temperature and sealed case temp. If you want to "imagine" I've placed all the components inside a case and sealed it, simply add 10°C ~ 20°C to ALL temps. However, this will not affect our primary goal which is to determine how well the PolarFLO cool's the Athlon 64 3500+.

Had PolarFLO sent a "kit” for testing I would have mounted as suggested, however, we’re only testing their CPU water block. PolarFLO has recently begun to focus on offering complete systems and manufacture an excellent pump, the TT Series DC based on the Laing DC4 pump motor. Another reason I've chosen to mount the components externally are the cumbersome sizes of systems built upon 1/2" ID tubing. One would have to modify most cases to fit a large double heater-core with fans and the obtrusive 1/2" tubing for all these components to fit neatly into even the largest cases. This then precludes entry level users or those lacking machinist skills. Many of us simply don't have the time or resources to make such modifications. For these reasons I've all but eschewed 1/2" based USA systems in favor of European designs. Had I not been so impressed with PolarFLO's design I doubt I'd be testing a 1/2" based system.


Onto testing -->