Rusty075 wrote:Pete, the only reason to change the size of tubing is to reduce restriction, thus improving flow rate. Going to a bigger tube actually reduces "velocity", but from a performance standpoint that impact is trivial. But you're right...it's impact on total system flow rate is small (much smaller than my exaggerated example), since the main point of restriction in a modern WC system is the WB's.
Tubing size does have very little impact on performance (although 1/4" to 3/8" is much more dramatic than 3/8" to 1/2"). As you correctly state, the major point of restriction in a WC system is the cooling block itself.
That said, 1/4" systems are typically designed for low flow, but still suffer a 1-2c deficit from tubing size alone in an identical system (from my own uncalibrated testing). Add that to the inherant inefficiencies of a condensor-style radiator (they work better in low flow systems, but still not quite as well as a heatercore style rad), the restriction apparent in the waterblock design (though it does look very cool), the lack of regulated active airflow and odd fin arrangement and I need convincing.
50c at load is impressive for a passive unit, but it only cools the CPU, while a decent air cooler supplies cooling air to motherboard components as well. In other words, I remain unconvinced that this will perform better than, say, a Thermalright SI-120, especially with a low-speed fan. Then again, it's a little tough to cram one of those into an HTPC case...so it does have a niche.
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