Thermaltake BigWater 760i can take the quad core strain

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Product: Thermaltake BigWater 760i
Type: internal water cooler
Web site: Thermaltake
Price: US$165, £100

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THE TREND of integrated water cooling packages, where nothing sticks out of the PC casing, continues - after all, quad core CPUs can start sucking up more than 150W TDP once overclocked, and something stronger than a regular fan may be required to expel all that heat out of the case.

The problem is, integrated packages usually need to fit within a double 5.25-inch storage bay. And, all the innards - pump, reservoir, radiator with a large fan and air outflow - need to fit in. This severaly limits the capacity and strength of the device's cooling - I'll never recommend any such device to cool both CPUs and GPUs, for instance. My previous water cooler of this type, the Nighthawk from Evercool, did have problems handling a 3.5 GHz quad-core Intel, so we stuck at everyday 3.33 GHz operation till now.

Thermaltake came out recently with BigWater 760i, its new entry in this segment, and I set up a system similar to my existing Evercool-ran configuration - quad-core QX6850 on an Asus Striker Extreme board with 3 (yes three) GB of Geil DDR2-833 CL3-3-3-5 memory, and interchangeable Asus EN8800GTX AquaTank and Leadtek 8800Ultra Leviathan - both GPUs independently water cooled with their own systems. The Antec 900 gaming casing was used with, Antec too, 850W power supply.

The BigWater 760i uses 50% thicker tubing diameter than the Evercool unit - so, the water flow should be greater, especially with its 500 litres per hour pump capacity. The 120 mm horizontal fan is much larger than the 800 mm frontal entry in the Evercool unit, but needs more empty space inside to ensure airflow towards the front opening, thus reducing the space available for the pump, reservoir and radiator - the latter one using dimple tubes to improve efficiency.

Also, it has a new superslim all-copper CPU waterblock. Even though its micro channelled water path is designed to ensure more liquid flow around and more efficient heat transfer, the waterblock is a bit too small for my liking. Thermaltake does offer larger waterblocks, too - the gigantic Volcano 4008 even has a built-in extra radiator, but weighs nearly a kilo - and, more importantly, its mounting system, especially screwing in the supports, leaves a lot to be desired, or else I'd recommend it as a great upgrade for the BigWater users.

How did it compare against my two references, the Evercool integrated watercooler and the old trusty Corsair Nautilus 500 external box? I ran the CPU both idle in BIOS after full mem test, and in Windows XP (idle and during burn in test done after 3DMark06 CPU run), using Asus PC Probe II to measure the temperature.

Here's how we stand:

As you can see, BigWater is ahead of the Evercool unit somewhat, but still definitely behind the old Corsair - while it gives up to 4 C lower temps than Evercool, it is still up to 5 C warmer than the Nautilus 500.

Overclocking-wise, I could reach stable, i.e. fully completed 3DMark and burn-in rounds - initial benchmark operation up to about 3.56 GHz CPU on The BigWater 760i vs 3.4 GHz on the Evercool, but nowhere near 3.75 GHz of the Nautilus. Not bad result, but still a plenty of room for improvements. Keep in mind, if you want to run tough 64-bit all-out CPU benchmarks like Linpack, these clocks may have to drop by another 50-100 MHz.

In summary, a good result for such a compact 2U high internal water cooling set. Most probably, one can't extract more strength within this package - as there are many PC tower cases now with 9 or more storage bays, many of them unused, I'd recommend vendors to look at 3 storage bay high internal high-peformance coolers next.

The benefits? Well, performance jump alone will be worth far more than the extra 50% in space spent. Now, you could put that 120 mm high efficiency fan frontally as well, saving a lot of space inside and enabling much larger radiator combined with a stronger pump, I'd even look at some kind of Peltier thermoelectic circuit, just alike those that BioHazard Computers in the US created for their high end PC systems, to further cool that water - or preferably, like Bio Hazard, non conductive liquid - well below the ambient temperature.

That would be a better return on the extra space investment than, say, much larger reservoir, as a bit longer tubing combined with slight reservoir increase can always accomodate more extra liquid. Also, TEC Peltiers hidden in the storage bays pose less condensation risk from their hot/cold plate operation than when sitting right on top of the CPU.

Not to forget, the added performance and cooling capacity could then finally create a strong internal liquid cooler able to really handle both the CPU and chipset and GPU - or maybe, for Intel Skulltrail or AMD QuadFX, dual CPUs and chipset!

Or, could anyone try to squeeze an internal water/liquid near-freezer fridge to cool it to below 5 C constantly? Taiwan's BitsPower showed such external device at Computex, but never delivered it... I know fitting in a true -40 C freezer, like what OCZ might come out with this year, might be impossible internally, but the fridge would be at least lighter and less space consuming. We'd talk reliable production 4 GHz everyday work on these quad cores then... ?

The Good
Decent performance in a small internal fitting, good even for dedicated dual GPU cooling

The Bad
The fan needs to spin faster to improve constrained cooling space

The Ugly
I wanna have internal fridge, finally. The UK price is ugly.

Barmaid's Report