Alphacool at Bit-tech

[Etacovda]

http://www.bit-tech.net/review/347/

Havent read it yet, but this should be interesting.

[jaydee]

What bugs me about this block is I made one very similar to it several months (8ish) ago but never got around to finishing it.

[BillA]

"The recorded deltaT for the NexXxoS HP Pro is higher than that recorded for the Cuplex Evo rev 1.1, which essentially implies that the water is extracting more heat from the water block."

stopped reading after such a dumb shit comment

[Les]

He is talking DeltaT(outlet- inlet)
However the values of 0.8c and 0.6c are probably unreliable
Not read any further myself

[BillA]

Les
he can't get to "more heat" no matter what he measures

unbelieveably ignorant
which makes the site editors fools, and the readers ? just common dumb guys I guess

[Les]

I consider the heat will vary according to the "C/W" of the wb; as discussed in pH's die-heat thread
Possibly like this:

[AngryAlpaca]

Heat doesn't have to be transferred through the WB, Bill, as the secondary cooling thread points out. I don't read garbage like that anyway (I can tell because it's "Bit tech" not "procooling" or "overclockers.com")

[BillA]

not by me, I see a shift of ~0.002°C/W with a 50% change in applied power
nothing like your graph, but my secondary losses are very tightly controlled
- and I believe my 'shift' is undefined experimental error

in the subject review both those wbs had the same heat load (given the setup)
the dT was a consequence of the different C/Ws - but WAY exaggerated (?)
NOT the heat pickup, thought I dealt with that myth years ago
hell Les, you posted the link

[BillA]

Originally Posted by AngryAlpaca

Heat doesn't have to be transferred through the WB, Bill, as the secondary cooling thread points out. I don't read garbage like that anyway (I can tell because it's "Bit tech" not "procooling" or "overclockers.com")

wrong AA
a good idea knows no source
do not prejudge, you'll miss too much

what was being measured ?
if you did not read, why post ?
to tell me about secondary heat paths ?
right

[Les]

Originally Posted by unregistered

not by me, I see a shift of ~0.002°C/W with a 50% change in applied power
nothing like your graph, but my secondary losses are very tightly controlled
- and I believe my 'shift' is undefined experimental error

Your very tightly controlled secondary losses are acknowledged in in my last graph in that thread :

[BillA]

Les
those values are changing because the flow rate was varied
how does that relate to this review with a single flow rate, though (somewhat) different ?

[Les]

Don't think the heat-source knows that it is varying flow-rate that is changing the "C/W"

[pHaestus]

Les:
Old numbers had some issues re: probes being moved around and offsets not carefully kept up with/written down. Now EVERY wb produces the same dT(Water in - water out) for a given flow rate, and if W is calculated from those dTs and flow rates then it stays very close to constant. The dT(CPU-water in) numbers are all ok (see the Pro/Testing graph or I'd be happy to send you a txt file), but the dT Water and the resulting W are not at all correct. My preference is 71W for power in all the wb tests based upon current (better?) testing.

Bill:
Just because the Bit-tech guys aren't so good at heat transfer doesn't make them or their readers dumb. Some VERY sharp electronics guys there (linear) and some top notch machinists/fabricators (pretty much everyone in fact).

[BillA]

then I really do not understand
IF the site has a technical orientation, then WHY do they not have an editor with technical competence ?

is this an acceptable article by their standards ?
if posted I have to assume so
conclusion ?
the editors failed to correct a technically inaccurate/wrong article ?

I'm not panning the individual readers of that site, just wondering who the editors are catering to

[Les]

Originally Posted by pHaestus

Les:
Old numbers had some issues re: probes being moved around and offsets not carefully kept up with/written down.

Remember the problems.In fact the value of the offset was the crux.

Originally Posted by pHaestus

Now EVERY wb produces the same dT(Water in - water out) for a given flow rate, and if W is calculated from those dTs and flow rates then it stays very close to constant. The dT(CPU-water in) numbers are all ok (see the Pro/Testing graph or I'd be happy to send you a txt file), but the dT Water and the resulting W are not at all correct. My preference is 71W for power in all the wb tests based upon current (better?) testing.
......

Happy with your dT(cpu - water in)

Would like to see some dT(water out - water in) data
Maybe a revival of the thread
I still believe that W should vary with both flow-rate and wb type.

[pHaestus]

I now test as follows:

• Turn on pump and fans on radiator; adjust flow rate to 0.5GPM
• Allow to run for ~15 minutes and reach steady state
• Write down offset between wb in and out probe.
• Fire up test PC and run tests with 60 minute equil time between points. Start out at 0.5 and increase to a final "max flow" point
• Turn off PC and wait 15 minutes
• Record final offsets

The last bit isn't strictly needed; every time I have tested in the last few months the 2 probes I currently used have had a 0.02C offset (outlet higher) at 0.5 and max flow. But I figured this was the best method to spot something that might go wrong in the future as it happens.

I see some slight variation in dT wb at really low flow rates from block to block. I think it's more to do with the fact that some wbs are less amenable to insulating the outlet barb (3 barb wbs SUCK for this). At 0.75GPM and above the W calculated from dT(water) is pretty much constant for all wbs until you get to 2.5GPM and above where I hit the limits of 0.01C resolution in calculating W

//edit: If I can finish my employment package today then I'll get back in the computer room tonight. Maybe after I finish running incoherent's wb I can play with some of this stuff in earnest.

[jaydee]

Originally Posted by unregistered

then I really do not understand
IF the site has a technical orientation, then WHY do they not have an editor with technical competence ?

is this an acceptable article by their standards ?
if posted I have to assume so
conclusion ?
the editors failed to correct a technically inaccurate/wrong article ?

I'm not panning the individual readers of that site, just wondering who the editors are catering to

Honestly I only looked at the pictures because of what you just said. BitTech has loads of possibility into turning into another ProCooling level site as the user base does have talented people. Problem is, IMO, the people running it are not as interested in that and more interested popularity and in making money off the site. That is what separates ProCooling from the rest. Money and popularity isn't an issue.

Certainly could be wrong though. Seems more like a bling bling site to me.

[Etacovda]

Bit-Tech is the only modding related site that i go to; unlike other sites, the project logs are generally good, the moderators are good, and lots of people post their logs there. Much like any other forum, they tend to find a 'focus' point if they're to turn into a good forum. Here, its watercooling; there, its modding.

However, he does succeed in trying to look technical and ending up with some results are questionable; i too stopped reading after a paragraph.

[freeloadingbum]

Originally Posted by Les

I still believe that W should vary with both flow-rate and wb type.

I think it should too but if secondary losses are only a couple of watts to begin with then it would have to take a large change in block performance before any change in absorbed watts are measurable, which is what pH's results seem to indicate to me.

[Etacovda]

What made me post it was the first part of the article -

"Supplier: Wizard Designs
Prices: NexXxoS HP Pro - £34.50; NexXxoS NB-A - £27.50; Heattrap RegCooler - £15.00 (fittings subject to extra cost)
Availability: Now

I've dabbled in watercooling for around a year now, and when I first got my feet (and CPU) wet, I remember coming across the most common watercooling argument; that of high-flow versus low-flow. This article isn't the place to debate the pros and cons of both, but when I came to make the choice between the two, I chose the latter simply because I found the hose in a European system to be a lot easier to keep simple and tidy. "

I dont think i need to say any more really.

[Etacovda]

http://www.nokytech.net/agrandir.php...exxxosxp/7.jpg

The inside of the XP, for those that wanted to see it. Base plate is the same as the HP pro, top changed.

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