My micro-channel concept block

[Ion]

Hi!
I like your block, could you please post a detailed drawing so that a complete rookie like myself could make one? Or is it classified? =)
Thanks!
Jon

[Cathar]

Some interesting developments on my front with the micro-channel block.

So I've cut out a small plastic disc and inserted it under the central inlet barb. Out of that disc I've cut a 5mm wide x 15mm long rectangle that straddles the channels, giving a reasonably small entrance for each channel to receive water. This effectively boosts the water velocity and creates impingement jet streams directly over the heat source.

I also picked up a Pondmaster 4200 pump today too, which pushes 1000lph at 4m head, and close to 4000lph in wide-open mode.

Okay, now we get to the interesting bits of comparing nozzled and non-nozzled performance with the Eheim 1250 vs the Pondmaster 4200.

An AthlonXP CPU was set to 1925MHz/2.15v using BurnK7 to generate full load.

The following CPU die temperatures were observed above the water temperatures (reading the on-die diode of the CPU).

Eheim 1250 - No nozzle - 8.0lpm: +18.5C
Eheim 1250 - Nozzled - 7.0lpm: +18.0C (really it's more like +18.25C - temps kept flipping)

Pondmaster - No nozzle - ~15lpm: +18.0C
Pondmaster - Nozzled - 12.0lpm: +17.0C

What's interesting here is that the nozzled block improves in performance as the flow rates are picked up more than the un-nozzled block.

The Eheim 1250 seems to be struggling to get enough flow to make the jet impingement principle work properly, but the pondmaster's extra pressure ensures that the water velocity through the nozzle is boosted enough to get real benefits of jet impingement.

What's uncertain here is where there's more to be gained in terms of the nozzled vs non-nozzled configuration as the flow rates are picked up even more, or if the full benefits of the jet impingement is being realised already.

I believe this is on the right track, by mixing the two proven cooling methodologies of micro-channels and jet impingement, coupled with a pump capable of the water pressure and flow rates to make it all come together as a functioning whole.

[bigben2k]

Great! Now try both pumps in series!

[bigben2k]

Come to think of it... I'm having a hard time picturing what you did. Do you have a pic, or diagram?

[Cathar]

Originally posted by bigben2k
Come to think of it... I'm having a hard time picturing what you did. Do you have a pic, or diagram?

Look carefully at the following picture at the centre barb. I cut the nozzle out of thick clear plastic so it's hard to see. You can just make out the texta marks of the rectange. The centre barb is slightly recessed back from the plate so the plastic disk with the nozzle sits in there and gets squeezed in place when the block is bolted together.

So rather than the entire ID of the lower barb opening onto the all the channels, just the small rectangle opening is made available for the water to squeeze through.

(Edit: Note - the second picture does not have the nozzle disk in place - I just put it there so you can better picture how the block gets put together and where the nozzle covers)

[bigben2k]

Interesting. That's what I thought it was.

I would still like to see a side-to-side test, with the center barb plugged, not just capped. As I mentionned, I believe that the water was jumping the channels, at a critical point, because the center barb was left capped.

Additionally, you could try a cap that would come down into the channels, for a higher velocity at the critical point.

Nice work. What do you have in mind next?

[nikhsub1]

Originally posted by bigben2k
...Nice work. What do you have in mind next?

Hopefully making some that WE can buy!

[Cathar]

Originally posted by bigben2k
I would still like to see a side-to-side test, with the center barb plugged, not just capped. As I mentionned, I believe that the water was jumping the channels, at a critical point, because the center barb was left capped.

Nice work. What do you have in mind next?

Okay. just retried the side-to-side config. This time I capped the central barb and put a solid plastic disc under the barb. Due to the plastic disc in place, this effectively forms a flat surface that sits flush with the copper lid atop the central core region. There is no water exiting up into the central barb as I can see that the plug/cap is still filled with air.

So how does it perform?

CPU @ 1925MHz/2.15v, K7Burn as usual.

Pondmaster - 11lpm - CPU @ +18.5C above water temperature.

So you can see that it is worse, which is also what I expected. You see when the water jets down atop the CPU core area, all of the water volume is hitting that region. When in side to side mode, despite how turbulent the water may be, not all of it is going to be down at the hottest region (it physically can't), so the copper has to do more work and carry the heat up the walls to be cooled, giving that difference that is seen. (At least that's my working theory).

Hopefully making some that WE can buy!

Am working on it. Making these blocks is NOT easy.

[dreamie]

Originally posted by Cathar
Unfortunately the A7V333 doesn't allow me to select sub-1.75v voltages. I know I can run this CPU at 500MHz/1.25v, and I'd love to see if the mobo started reporting CPU temps below ambient.

........

The A7V333 also reports the in-socket diode temperature and it typically sits at 10C higher than the CPU diode. Of course none of this stuff is calibrated properly, but it is good enough to pick up differences.

you can get 1.45V by shorting the first bridge of the L11 and leaving the others separated.

BIOS version 1011, 1012 and 1013 have fixed this temperature problem.

[Cathar]

Originally posted by dreamie

BIOS version 1011, 1012 and 1013 have fixed this temperature problem.

Uh, no they haven't.

I'm using 1011 right now, which I reverted back to from 1013 when I had stability issues there with my other hardware in my system (a common problem reported with the 1013 BIOS over at AMDMB). For both the 1011 and 1013 BIOSes I see the same temperature issue. In fact, I have to be using a 1011 BIOS or newer since the on-die diode reporting is not supported in BIOSes prior to 1011.

[nikhsub1]

Cathar, have you tested performance with one of the outlets closed? I'd be very interested to see how it would perform going in the center, and out only ONE barb. Sorry if this has been asked/tested already.

[dream caster]

Originally posted by bigben2k
I was just thinking (uh oh!)...

If someone here wants to try to reproduce this kind of cooling, one could take a copper HSF, and add barbs and a lid.

From this list , I found the following were of a copper finned design:
(of course the fin spacing is WAY off, but it's not too bad)

Thermalright SK7

Vantec 1U

Global Win CAK II 38 and CAK II 16

Evercool CUD-725

Dynatron DY1206BH-638

Cho-Liang CB0315U-17

CoolerMaster HSC-V62

Dynatron DC1206BM-R


Now, never mind how they perform as air coolers! BTW, some of these have soldered fins, some have skived fins (fins are shaved off of the copper base). The skived models would probably offer better heat transfer from the baseplate.

(I avoided listing those HSF where the middle fins were removed for the mounting bracket).

What about using a dremel?

I had the idea of similars blocks and my thought was to build them using a dremel or a dremel-like tool and a reinforced cutting disk having the dremel in a fixed stand and a guide to move the blokc inside a thight fitting slot and advance the whole thing sideways a fixed amount (channel + fin thickness) each time you completed a slot.

I just measured the thickness of reinforced disks cuts and it is 1mm and a 5mm deep slot should not be so difficult.

[decodeddiesel]

Damn Cathar, that pump is expen$ive!! It is similar to an Iwaki though, something I hope to get soon...

[Cathar]

Originally posted by decodeddiesel
Damn Cathar, that pump is expen$ive!! It is similar to an Iwaki though, something I hope to get soon...

$200 AUD, or around $105USD, tax inclusive (10%) is what it cost me.

Not quite that expensive.

Expensive if you walk into an aquarium and try to buy one retail, yeah. Not expensive if you go to a cut-price outlet store.

[decodeddiesel]

True...good to see it helped though.

[DodgeViper]

Hey Cathar, ever thought of trying a dual output rad. I made this rad today. Got to finish the shrouds, but will be done by the end of the week.

[DodgeViper]

.

[g.l.amour]

i feel like a total amateur looking at all the heavy equipment u guys r using. my shrouds are mostly comprised of cardboard and ducttape. works though, but i'm not gonna win any beauty contests with em.

[morphling1]

Damn I just love that rad, is that one also from Chevrolette Chavette? I found one from Opel Corsa it's very similar, the only thing is it's 19cm wide, and that 1cm to much to fit it in most cases. What are dimensions of that rad?

[Cathar]

No, never used a dual-outlet radiator.

What are you using it for?