Laing DDC (Swiftech MCP350/355) Names & Info

[perfection]

hey does anyone have a direct comparison between the Laing DDC2 and DDC1?? How loud are they??

[fgw]

hey does anyone have a direct comparison between the Laing DDC2 and DDC1?? How loud are they??

from looking at your sig i can see you already use a laing ddc1. here is a link to a howto to modify a ddc1 to a ddc2:
http://forum.effizienzgurus.de/f23/h...id=29#overview
this can be done on a certain revision of ddc's. you have to verify if you have the correct one. looks like laing manufactures just one ddc and use a bridge to decide if it is a ddc1 or ddc2. just open up your ddc and solder in this bridge. now you can easy compare the two.
i did this mod and soldered a switch to my ddc. i can now switch between ddc1 and ddc2 modes. the difference is 3900rpm vs. 4500rpm and in my loop about 1.8liter/minute vs 2.25liter/minute which is a 25% increase in flowrate.
running at 4500rpm the ddc is noticeably louder but it's not that bad at all.
on the other hand, the increased flowrate does not much to my cooling performance. think i'm on the lower end of flowrate anyway. may be there would be a difference in cooling performance if i could up my flowrate to 4liters/minute ...
as there is no need for more cooling at the moment, i stick to the ddc1 mode for now.

[ubi]

i did this mod and soldered a switch to my ddc. i can now switch between ddc1 and ddc2 modes. the difference is 3900rpm vs. 4500rpm and in my loop about 1.8liter/minute vs 2.25liter/minute which is a 25% increase in flowrate.
running at 4500rpm the ddc is noticeably louder but it's not that bad at all.
on the other hand, the increased flowrate does not much to my cooling performance.

What is the difference between the watertemps?

[fgw]

What is the difference between the watertemps?

there is NO DIFFERENCE at all! let my system idle for some time to stabilize temps a bit. fans on the radiator were running at 700rpm during both tests.

• first i run the pump in ddc1 mode (3900rpm) for 10 minutes. core temp reads 29c for both cores. watertemp was 26.9c.
• next i switched to ddc2 mode (4500rpm) for 10 minutes again. coretemp and watertemp stayed the same.

as said before, i have a very low flowrate and the change from 1.8liter/minute to 2.25liter/minute does not make any difference. may be if you are using a less restrictive loop and your flowrate would change form 3l/m up to about 4l/m you could see a difference.
in my environment, the limited change in flowrate has no effect on temps!
also, did this test during idle, because during orhtos, temps are fluctuating by some degrees which would give misleading results. if i see no difference during idle i doubt there would be any difference during load conditions at all.

the impact of fanspeed is far higher than the impact of flowrate:
running the pump in ddc1 mode again, i switched the fans on my radiator from 700rpm to 900rpm. i could watch temps going down: starting from coretemp readings of 29c and a watertemp of 26.8c, temps dropped to 28c in coretemp and 26.1c for water after 10 minutes. after witching back to a fanspeed of 700rpm, watertemp started rising slowly again ...

[Petra]

in my environment, the limited change in flowrate has no effect on temps!
also, did this test during idle, because during orhtos, temps are fluctuating by some degrees which would give misleading results. if i see no difference during idle i doubt there would be any difference during load conditions at all.

There is a difference, it just may not be detectable with onboard temperature sensors (lack of resolution). That said, the difference would become more pronounced (and possibly detectable with onboard sensors) at full CPU load because you're putting more heat into the system (i.e. a tiny change in thermal resistance due to increased flow can become a very large change in CPU temperature, provided that you're applying enough heat).

A simple explanation for the small difference in flowrate, however, would be the DDC-3's abysmal max head pressure (thus, making the difference between the DDC-3.1 and DDC-3.2 pretty small...especially when used in a restrictive loop).

[pss75]

According to the user manual posted a while back, this pump must not pump downwards! Could anyone explain y this is as i am building a case with these pumps facing down!? I presume it may have something to do with the original top and that a modded top should allow the pump to pump downwards?!? (not upside down!) Cheeers

[Maviryk]

According to the user manual posted a while back, this pump must not pump downwards! Could anyone explain y this is as i am building a case with these pumps facing down!? I presume it may have something to do with the original top and that a modded top should allow the pump to pump downwards?!? (not upside down!) Cheeers

As with all water pumps, you must first PRIME the pump with water in order for it to work properly, otherwise you will burn out the motor.

However, once it is primed with water, you can mount it anyway you want to, unlike most significant others.

[jinsean]

i did this mod and soldered a switch to my ddc. i can now switch between ddc1 and ddc2 modes. the difference is 3900rpm vs. 4500rpm and in my loop about 1.8liter/minute vs 2.25liter/minute which is a 25% increase in flowrate.
running at 4500rpm the ddc is noticeably louder but it's not that bad at all.
on the other hand, the increased flowrate does not much to my cooling performance. think i'm on the lower end of flowrate anyway. may be there would be a difference in cooling performance if i could up my flowrate to 4liters/minute ...

1) How'd you know the exact RPM between the 9w & 18w settings?

2a) Do you have some damper / gel pad / decoupling system in place for your pump?

2b) Would you say the DDC2 setting is still quieter than a 900-1000rpm 120mm fan? Or if you can't reference the noise level to a fan, then maybe with some other component in your system (e.g. what's louder or quieter than the DDC2 setting).

3) Could you fill me in on how to create a switch for the DDC? It's probably really simple, but never took an electronics class in high school =/

Thanks.

[fgw]

1) How'd you know the exact RPM between the 9w & 18w settings?

ddc gives a rpm signal as fans do. just connect it to a motherboard fan header and monitor rpms in any monitoring software.

2a) Do you have some damper / gel pad / decoupling system in place for your pump?

just used the standard mounting hardware that came with my pump. will add a picture later.

2b) Would you say the DDC2 setting is still quieter than a 900-1000rpm 120mm fan? Or if you can't reference the noise level to a fan, then maybe with some other component in your system (e.g. what's louder or quieter than the DDC2 setting).

this is very hard to tell and very, very subjective. but i wll try: usually i run my six s-flex sff21e (1200rpm) fans at 700 rpm. at this speed, although i'm using six fans(!) they are almost inaudible. if listening very close, the pump could be identified when in ddc1 mode. when in ddc2 mode, the fan needs to rev up to about 1000rpm to be as loud as the pump. at 1200rpm the fans are definitely louder than the pump in ddc2 mode.
as i said, this is very subjective and i'm using six fans together on my rad.
and don't forget the harddisk. if my seagate barracuda kicks in, you don't have to care about the pump or the fans ...
in general, i would say this pump is almost inaudible in ddc1 mode and still very quiet in ddc2 mode!

3) Could you fill me in on how to create a switch for the DDC? It's probably really simple, but never took an electronics class in high school =/

Thanks.

as the pump is checking the status of this connection during startup, you have to switch the pump off and on after connecting the wire to mod the pump from one mode to the other. i use a three position switch with two switched contacts. in the center position the pump is off. in the other positions its either in ddc1 or in ddc2 mode. a two position switch would do here. just ignore the center position and connect everything the same. i prefer to be able to switch the pump off. this helps during refill and test.

* ignore the typo near the blue connections. it should read 12V instead 12C!

• the red connections are coming from the psu 12v rail. which is usually the yellow cable on any 4 pin peripheral connector.
• the blue connections are going to the pump 12V supply, which again should be the yellow cable on the pump connector.
• the green connections are routed to the soldering point as described in the how to
  here
  the only difference is, that you are NOT connecting this soldering point to the adjacent soldering point.
  instead you route a wire outside and connect it to the switch like the green wire above
• the black wire from the pump connector runs to the black ground connection on the 4 pin peripheral connector as before

[perfection]

just wondering, this is the OClabs top here but all tops are very similar is design.

wouldn't it make more sense if outlet was on the right hand side as it looks like impeller spins clockwise. wouldn't it be better with the outlet on the other side??

[serialk11r]

just wondering, this is the OClabs top here but all tops are very similar is design.

wouldn't it make more sense if outlet was on the right hand side as it looks like impeller spins clockwise. wouldn't it be better with the outlet on the other side??

I think it gets a lot less pressure that way.

[Nikos]

Hello, during my R & D tests I have also tried the outlet position on the other side as your request and the results was very intresting: the pumps doesn't works at all!

That's why all the TOPs have had the outlet barb on the left side, because of the impeller geometry that implies it.

just wondering, this is the OClabs top here but all tops are very similar is design.

wouldn't it make more sense if outlet was on the right hand side as it looks like impeller spins clockwise. wouldn't it be better with the outlet on the other side??

There is only two ways to increase/reduce the absolute pressure of the DDC pump: 1. change the internal geometry of the impeller (impossible for us but not for laing) 2. change the geometry of the TOP (the only way for us).

I think it gets a lot less pressure that way.

Kind regards, Nikos

[Petra]

2. change the geometry of the TOP (the only way for us).

3. Reverse engineer the motor and make modifications (maybe... I have yet to fully delve into the matter, but it's hypothetically possible and well within our means)

The performance capabilities of the DDC pumps are, primarily, motor-limited (especially if you start talking about the 9W DDC-3.1 and 18W DDC-3.2).

[Nikos]

3. Reverse engineer the motor and make modifications (maybe... I have yet to fully delve into the matter, but it's hypothetically possible and well within our means)

The performance capabilities of the DDC pumps are, primarily, motor-limited (especially if you start talking about the 9W DDC-3.1 and 18W DDC-3.2).

Hi Petra

I didn't spoke about motor modifications as there will be warranty lost for the end users and also because we're not the manufacturer, so we can't change the motor. Perhaps laing will decide to apply some modifications on the DDC motor in the near future but as we've already saw untill now, all comanies try to optimise the production costs and the example in this case is the same motor either for 10 and for 18watt.

About the impeller geometry, perhaps, there is another physical limit on the machine capabilities, otherwise I think that they already made a new impeller and they didn't change only the inlet hole from 12 to 8mm.

Kind regards, Nikos