Now finally some results! First up, the individual configurations testing.
<p>Unlike many other blocks on the market, Swiftech prescribes the orientation of the block so there's no orientation testing here, just the results of the XT against the GTZ and GTZ SE. In addition, I tested the XT with the alternate inlet positioning "XT Alt" and observed roughly a quarter of a degree drop in performance. The drop in performance is largely from the drop in flowrate. On my testbed, flowrates went from 1.38GPM to 1.27GPM by changing the inlet positioning; the small drop in performance is the price to pay for compatibility with large compression fittings. It should be noted that the XT's chief rival, the Heatkiller 3.0 LT/Cu, provides no compatibility with larger compression fittings, aside from purchasing additional adapters/fittings from Bitspower or Feser or elsewhere. </p>
In addition to basic testing, I also attempted to tweak the Apogee XT by using the familiar "silcone mod" I debuted with my Heatkiller tests. I’ve dubbed the tweaked version of the XT as "XT+" and it provides roughly a 1C increase in performance at the expense of 5 minutes of work, a couple dollars of 100% silicone (many varieties are available), a few Q-Tips, and a slight increase in block restriction (bringing flowrates in my testbed from 1.38GPM down to 1.26GPM). Here is a picture of my mod before I installed it (it obviously doesn’t have to be perfect to perform great–mine is definitely not perfectly applied!).
<p>Now that we've figured out what the best configuration is for each block, let's chart its performance over the entire flowrate spectrum.</p> <ul> <li><b>Very High Pumping Power</b>: All three MCP355 pumps and the D5 are on at full speed--this has a very similar PQ curve to a pair of RD-30s at 20V.</li> <li><b>High Pumping Power</b>: Two MCP355s with EK V2 tops are on at full speed. The other two pumps are off.</li> <li><b>Medium High Pumping Power</b>: A single MCP355 with XSPC V3 top is on at full speed. The other three pumps are off.</li> <li><b>Medium Pumping Power</b>: The stock D5 is on at full speed and setting 5. The other three pumps are off.</li> <li><b>Low Pumping Power</b>: A single MCP355 with XSPC V3 top is on at minimum speed (~7.7V, ~2450RPM). The other three pumps are off.</li> <li><b>Very Low Pumping Power</b>: The stock D5 is on at minimum speed--setting 1. The other three pumps are off.</li> </ul>
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Note: I do 5 mounts at “Medium High” then take the best config of a block and test the whole flow spectrum (after a TIM curing session) then realign that curve with average of the 3 median mounts to give you the “Adjusted” data.
<p>More graphs for your enjoyment...let's start with reusing the flow vs. temperature data, but including pump heatdump (i.e., CPU vs. air temps). I have two iterations of it: CPU temperatures vs. my air temperatures and a setup with my water-to-air delta included twice more. The latter is to mimic a setup with one third the radiator power of my setup (roughly a 120x3 radiator with 1600RPM fans). </p>
<p>Note: these results are derived from adding the water-to-air delta three times to my water temps. I add them three times to emulate the radiator power of a loop with 1/3rd the radiator power mine has. I use 2xMCR320s with push-pull 2200RPM Yate Loons and the data emulates the conditions of a loop with a single 120x3 radiator with ~1600RPM fans. </p> <p>Here we see something fascinating--low flow resilience from a high performance block. While this block performs amazingly at 'normal' pumping power settings (single/dual DDC3.2/D5), it also has very little performance degradation from reduced flow. What does that mean in Layman's terms? For a low-flow system (one with a weak pump and/or a lot of other secondary components and/or 1/4" tubing), this block really distances itself from its predecessors--its performance is easily the best in the business.</p>