I found a new original MCP350 today!

I was coming back from south Atlanta today and stopped by a Microcenter on Delk Rd.. In rummaging through their pumps out of curiosity, I managed to find an MCP350 box that still had the original black head pump inside (took the top off and looked once I saw the tag on the pump). I hadn't noticed until a thread recently that the DDC has also been dummed down along with the DDC-2 pumps to form the DDC 3 series pumps (blue top). I couldn't resist snapping up this pump as the DDC pumps never had the reliability problems of some of the DDC+ 18w pumps.

Coincidentally, they also had an original DDC-2TPMP pump also (red top) new still in the box from Danger Den left.

They also had a new MCP655 vario for only $70 new, which is a good deal given that most places online want $85 for it.

I smell a side-by-side compairo!

In my tests, which were very rough, I found ~1°C difference between an MCP355 stock, an MCP355 Petra's, and an MCP655 @ P5. The MCP655 was the worst of the three and the stock MCP355 was the best with Petra's falling in between. Moving the MCP655 to P3 adding another 1°C to the dT. This was all with very high-speed fans on a single heater core and 3/8" tubing. Results for lower speed fans were very similar except the P3 setting made almost no difference.

Changing to 1/2" tubing resulted in slightly lower temps for the Storm CPU and slightly higher temps for the Apogee CPU. I assumed the extra turbulence created by the faster water speed of the 3/8" tubing as it entered the Apogee was the cause for this ...

I flow tested the original MCP350 a while back with stock top vs my own made top and found about a 50% improvement with the add-on top over the stock top in flow (80gph vs 167gph using the bucket/stopwatch method). So the question is just whether the increased flow ends up putting the loop flow rate above a point at which the temp difference is measurable.

Well, I just did some snooping around and found a direct PQ curve comparison between the DDC 1 and the DDC 3.1 on Petras site. Apparently there is very little difference between the two in pressure/flow. The changes become more evident with the DDC 3.2/MCP355 between the 2 and 3.2 versions.

Now I guess I'll just sit here and ponder whether I should just go ahead and take it back or not. I bought it for a backup, but if there is actually little difference between it and the newer 3.1, I may as well just take it back and wait until the day when my current MCP350 dies and replace it.