Hi Karl thanks so much for the link... will def give that a good look at.
Re the cards, yes am a bit puzzled by the 2-3 degree differential between GPU1 and GPU2 temps... all the research I did on the net pointed to parallel = equal temps, and also that parallel reduced flow restriction compared to series. I thought that parallel plus dual D5s would offset the restriction additions of the 90 degree fittings and the QDCs. Not to mention use of 1/2inch ID tubing.
A few notes on the fans. Fan1 fans are the 5 EK Varder Furious F55-120 fans mounted to the front intake Rad1 (EX-360). These are minimum 1200rpm and maximum 3000rpm (ie the graphs below are scaled, not min/max). So on the test above these basically went less than 50% of their capacity.
The Fan2 fans are WingBoost 2s (Rad 2, 2x push), 500 min rpm and 1500 max rpm. I didn't log Rad 3 (also WB2, but 4xfans in push/pull). So neither seemed overly pushed.
However, what I have learned is that the 1200 min rpm of the EK Varders is too loud for me when considering a system that is "silent" when at rest - as the minimum this fan goes to is 1200, I can't get PWM control to reduce the Varder below min speed of 1200, so am considering ordering some replacements in the form of 5x Wingboost 2s (which can spin to 0rpm under aquasuite), subject to stability testing to see how far the Varder RPMs go under a full system stability test, to see if the WB2 maximum speed of 1500rpm is appropriate for a high load situation (ideally need a fan with 500rpm min, 2000rpm max!)
Speaking of stability tests, here is a 20 minute AIDA64EXtreme stability test for CPU / FPU / GPU / RAM.
Test started just after the log began, and ran for 20 mins. Temp1WC Inline is the water temp. CPU Package is the package temp, not the CPU temp. Max Package obtained was 79C peak, average 57.9C.
Here is the AIDA64 statistics page:
And a Firestrike rating:
http://www.3dmark.com/fs/4691516
Will run some longer term stability testing, as you say temps are still climbing. However, I cannot yet match these temps in a gaming situation as of yet - ie stability testing is pushing the system far more than games have to date - I will post some results from gaming in due course.
Thank you
Ps- flow rate is not displayed on the graphs, it's a fixed setting at 2.5 on the d5 varios