the latter

http://www.thermal-management-testin...PQ%20curve.gif

Oh, great, so if I understand correctly there will be THREE versions now? This reminds me of a certain OZ mfgr... how the heck are we supposed to keep track? I mean, I have 2 already and I'm not entirely sure which ones I have, although they are very quiet. I am now after a 3rd, but I want a matching pump! Oh joy...

No doubt what the hell do they think they are pulling, improving a product :mad: just like Intel and those new fangled Pentium 4s, as if the Pentium Pros weren't good enough... dishonest business I tell ya. :p

Bill could you please post the x-y values for that graph, I'd like to add them to a comparison graph.

Clarification please: MCP650 is a "revision 3" reduced noise/reduced performance model?

hmm. you wouldnt happen to know when the new batch comes in or if they still have oldest ones left, would you?
I want to buy one of them but dont want the noisy nor the weaker one!!
I want rev2 !!lol
DD hasnt responded to my mail yet so if anyone knows the stock-situation regarding D4s over at DD please speak up.

SenC.

the performance of the MCP650 is as shown above,
it is the 'reduced noise' current production model, dated 7/04

ask the affected vendor(s) about differences, no ?

note that this rev 1, 2 , 3 etc. is something you guys are making up

Bill I came to the '3 rev.' conclusion after reading what mikoto said a few posts earlier in the thread.

Here was my own take upon the D4's performance curve with the original "noisy whining bastard" pumps I have here. I rang up one of the Laing engineers by phone, forwarded him my results and confirmed with him that my results were accurate to within about 5% of what Laing were seeing. My pump did seem a little more powerful than theirs. Upon testing my second pump I found its results to far more closely match Laing's own testing, so I guess the first pump I got which is measured in the graph below was a bit of a "gem".

http://www.employees.org/~slf/curves.../laingd4-3.png

much better to never start the (false) rev thing, as it will never go away

specifications subject to change, this is how improvements happen

Yeah, wish I had considered word choice a little before posting that. I can see how the rev. thing could be a little testy for resellers. Sorry, tasting a little foot over that. Then again, kinda tough to fool an astute crowd. Revision is hardly an uncommon designation for a product that undergoes multiple changes in design.
Certainly the product has evolved, presumably in response to consumer demand. Let's leave it at that. Don't want to give Bill headaches.

there are more players than are apparent, coordination is important
it is the mfgr that sets the nomenclature, not resellers unless private labeling
just trying to keep the oars in sync

I like this new pump (specs, size, DC). Price, though? Less than the MCP600, correct? You don't know how much less, do you? Hmm...

am i missing something or does the graph BillA posted look a *lot* weaker than the one cathar posted? i mean, eg at 2 mH20, Bill's is flowing 6lpm, while cathar's is flowing 12!!!

Guessing that modifying the original square wave to whatever it is now causes that...waiting for more testing here.

surely there's a mistake or something. i'm a bit of a n00b, but wouldn't u just go the mcp600 instead then? at least it's a known quantity etc.

Umm, Cathar's chart shows a pump which is what he calls "a gem" in terms of it's ouput at 12v. There will be variance from pump to pump and, Cathar's test is not 100% accurate, he has said such himself. From Laing's charts I calculated the muffled pump to have approx. 1.5 feet (less than 1/2 meter) less max head. NOt something that is gonna really change the temp in your loop.

Laing has a new chart out already, I'll have to look, I think I have the old one around somewhere.

well fair enough that it might not make that much difference, but it's not exactly mild variation is it? iirc it was only about 5% off laing's figures at the time...6 vs 12lpm at 2 mH2O is not what i'd call a small difference. max head is not really that relevant, as stated. to match the 'old' version at 12lpm and 2 mH2O, the 'new' revision would have to drop to 1.2mH2O. that's quite a difference.

btw, i am just quoting numbers at you. as i said, w/c n00b, so clueless as to the practical effect of the above :).

Also, I think Bill mentioned that is a prototype of the 650. Its possible that the production model has differetn characteristics.