In search of silence...pumps!

I know this is something that's been hashed and rehashed a million times. But I've yet to see a definative answer. While all peformance charts agree, the noise level reports are very subjective.

I just replaced my trusty Mag 3 with a MCP650 (D4). The Mag 3 made a soft hum that was pretty much only audible when the 120mm Sanyo Denki fan's at 7v were turned off, or your ear was against the case with the fans on.

Now I'm using Delta WFB12121M's, which are a fair bit quieter than the Denki's were. Even with the fans at 12v I can hear the whine of the D4 over the fans. Very irritating to say the least. Sounds like a cordless beard trimmer.

After doing some research here and SPCR, it seems the only options in my case are a CSP-Mag, modded MCP350 (DDC) or a MCP655 (D5).

While I'm leaning towards the D5 for power, I'm afraid it will show it's ancestry in the D4. The DDC is an good choice, but after I mod it (likely make/buy top) it will cost more than the D5. Right now the CSP-Mag seems like the most attractive choice. It's noise levels are being reported to be lower that the DDC. But the low head rating raises questions.

My current loop consists of a Chevette HC, about 3ft of 7/16" tubing, Maze 4 GPU block, and a custom CPU block that's very restictive (I'd say more than a Storm, but I think I'll pop it open and modify it). The pump will need to work with my BIX2 and Dtek WW substituted for former block and rad, once I get my Conroe.

If you have owned these pumps and can make comparisons on the noise levels, I'd appreciate if you would post your opinions.

i modded an mpc350 ... not hard if you have a bit of tooling and are careful and use good epoxy to glue the barb in and build up over the top (my first glue job failed after heavy handling so i redid it with jbweld epoxy - now very solid).

350 is very quiet ... i could never tell if it was working when testing it unless i could see some bubbles in the line or touching it.

I was going to build another system with a 655 till i decided on a farm cooling system. the 655 is also very quiet ... not quite as good as the 350 but almost ... and the reason i bought it was that specs were similar to the modded 350 but without the extra work of modding. About the same price locally after including the mods.
The 350 has been running on 2 different rigs 724 for about a year now without touching it.

I gather there are newer models of both pumps out now (mine are swiftechs).

they will be supplemental/spares pumps now on my farm cooling setup which will have primary pumps as iwaki 30 and a used t2.

Thanks pscout. So you have both the MCP350 and MCP655? Can you describe the tone of sounds relative to each other? Can you hear either one over, say, a hdd seek?

damarble said:

Thanks pscout. So you have both the MCP350 and MCP655? Can you describe the tone of sounds relative to each other? Can you hear either one over, say, a hdd seek?

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I have never run the 655 in a case. I have not noticed any whine but then it is not in use in a case so i can't say if it would be noticable.
Out of case is it noisier than the 350 for sure ... but not a lot.

You would not hear the 350 over any other case noise like fans, psu.
I have sata drives that are noisier when in use - i have mostly seagates which are very quiet.


Of course, your hearing may be better than mine. But in general i am pretty sensitive to high pitched whines.

I like my D5. I have it at 5 and I can't hear it over the sound of my 120mm rad fan (93CFM fan, made by Masscool)

from what I know, the DDC pump rev.2 is very quiet, more than the DDC (mcp350), and it has more power than the DDC.

You can get it at dtekcustoms.com or dangerdenstore.com

I have a D5, and just recently did a side by side sound comparison of the MCP350/DDC 10w and the DDC Rev2 18w. The D5 at number 5 is a lot louder than either DDC. At number 3, it about on par with the rev2 18w as far as volume goes, but it has a much higher pitch and hence is a lot more noticeable. Between the 10w and the rev2 18w, the 18w is noticeably louder, although probably only to the tune of about 3-4db, and does vibrate significantly more which as long as you use foam should not be an issue. It has a slightly higher pitched tone than the 10w. If you want absolute silence, then go with the 10w. It is very, very quiet. The 18w is just noticeably louder, but that is it, and the D5 is louder than both.

In my opinion, the MCP350/DDC or the rev2 DDC modded or used with an acrylic top are the best way to go for noise/performance ratio for a person looking for a quiet system. The D5 is NOT the choice for the quietest setup, although it beats the awful whine of the D4 hands down.

My experience mirrors voigt's although I only have the 18w (355?) version to compare.
The MCP655 does have a very noticable/irritating whine to it.
Furthermore, the flow modded 355 can push as much water as it's bigger brother from a much smaller package which can simplify installation if space is at a premium.

Thanks for the input.

Voights, you machined your own plexy top, correct? I'm thinking my choice now needs to be the 10w DDC, and I want to make a top similar to yours.

The only problem I see with choosing the 10w DDC is they seem to be virtually unavailble. I'm almost forced to go used, but I haven't seen many for sale. The 18w might be acceptable, but now the D5 is completely ruled out.

Unfortunatly for me I can hear a lot of things other people can't. I can hear the buzz of a laptop power brick for example, when nobody else can. But the noise doesnt bother me a lot, unless it's high pitched.

Has anyone here compared the CSP-Mag to the DDC? I've heard mixed reports that it may be quieter still.

goodgod said:

from what I know, the DDC pump rev.2 is very quiet, more than the DDC (mcp350), and it has more power than the DDC.

You can get it at dtekcustoms.com or dangerdenstore.com

Click to expand...

Sorry, but I beg to differ...in regards to the difference in sound on the mcp350s.

I have modded both the 18w and the 10w mcp350. the 18w does have a slightly louder 'hum' compared to the the 10w. I have the 10w in my loop and did the mod on the 18w for krag 2 weeks ago. His modded 18w pump was noticeably stronger than my modded 10w after the mod but it did have a louder pitch to it. Neither pump is 'whiney' tho...just a difference in 'loudness'. You most likely won't be able to hear either pump when it's in your case.

I'd recommend sticking with the mcp350(either wattage model). then do the mod. These are great pumps and have great reliability.

Ok, The thing here everybody is
How did you have your pump mounted when you listened to it?
Mounting makes all the differance in the world.

My Via Aqua 1300 has a pretty bad vibration that if mounted on a solid surface creates a horrible resonating sound that can be heard throughout my condo. However I took two pieces of low density anti-static foam rubber with the ridges and put it so the ridges were facing down and the flat surface up and put the pump on top of it and cannot hear it with the system off. Only my radiator being slightly warmer than room temp or the ever so mild vibration in the system lets me know its running.

I did do a mod to the impeller to make it quieter but I think that might have imbalanced it some. Have thought of taking it out and using a rig I have for balancing Radio Controlled tires to balance the impeller but not sure if the vibration is inherent with the pump's magnetic operation on the impeller or the weight being off, so don't want to make a bad thing worse.

Since no one has voted for the CSP-Mag I'll do so. I wrestled with the very same question about 3 months ago. Failing to find a concrete answer (there just isn't one), I plotted out the PSI delta vs flow rate and the C/W vs Flow for each component I was going to purchase along with the MCP350, MCP655, and CSP-MAG. When all the dust settled there was .58 deg C temp difference between the CSP-MAG and the MCP655 on #5 setting.

I purchased the CSP-Mag for my loop and have never been happier. The pump is suspended from the tubing at the top of my case and is completely inaudible with 3 Yate Loons (DSL12s I think) @ 7V and the NF4 chipset fan on my DFI in my system. As a previous poster mentioned pump mounting is the #1 item that will make or break your "silent" system and noise level will vary (sometimes substantially) between pumps in the same model line.

Components are as follows:
A64 3000+ Venice assumed 100W
Nvidia 6600GT assumed 50W
Apogee
MCW60
BIPIII

Results: Temp degrees C (Water - Air)
CSP-MAG 11.28 deg
MCP-350 10.81 deg
MCP655 #5 10.70 deg
MCP655 #1 12.42 deg

Thank you effnish for the well thought out post. You give some strong points in favor if the CSP-Mag. I think it should work fine for me, since the components I'm cooling are very close in heat output to yours. The only thing that worries me is my rad is 1/3 the size of yours, and I have no room for a bigger rad.

sunrunner20 said:

Ok, The thing here everybody is
How did you have your pump mounted when you listened to it?
Mounting makes all the differance in the world.

Click to expand...

I tested both mine and krag's the same way with the same tubing and bucket.
both were on 2 bunched up thick cotton paper towels...not like any flimsy 'brawny' either. I can tell you when I mounted my 10w to my motherboard tray via screws and grommets the tray did 'ring'. I have my pump velcro'd now. 3M adhesive backed.. And no more vibration ringing.

VballCoach said:

I tested both mine and krag's the same way with the same tubing and bucket.
both were on 2 bunched up thick cotton paper towels...not like any flimsy 'brawny' either. I can tell you when I mounted my 10w to my motherboard tray via screws and grommets the tray did 'ring'. I have my pump velcro'd now. 3M adhesive backed.. And no more vibration ringing.

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Its very hard to imagine that grommets were transfering vibration. What kind of grommets were they?

just rubber grommets but I think the mounting screws may have been contacting the pump housing...probably screwed 'em in too tight

damarble said:

Thanks for the input.

Voights, you machined your own plexy top, correct? I'm thinking my choice now needs to be the 10w DDC, and I want to make a top similar to yours.

The only problem I see with choosing the 10w DDC is they seem to be virtually unavailble. I'm almost forced to go used, but I haven't seen many for sale. The 18w might be acceptable, but now the D5 is completely ruled out.

Click to expand...

Yes, I did make my own top which was a trial and error process but in the end has worked out well. You can readily find the 10w.

The one I compared with I just bought from performance-pcs not two weeks ago (they also now are carrying the Alphacool tops for $30 + shipping). The MCP350 is the 10w version.

sunrunner20 said:

Ok, The thing here everybody is
How did you have your pump mounted when you listened to it?
Mounting makes all the differance in the world.

Click to expand...

You do have a point. I compared them sitting on top of memory foam (free sample that I got through the cyber deals section). This foam does an excellent job of absorbing vibration.

voigts said:

I compared them sitting on top of memory foam (free sample that I got through the cyber deals section). This foam does an excellent job of absorbing vibration.

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You got the Temperpedic sample too?
I have a chunk sitting here that I plan on using for the next build...freaky stuff, isn't it?
Feels kinda like a sponge soaked in hand lotion.

Bet it makes a great bed.

One of these days I should watch the DVD they included....

voigts said:

You can readily find the 10w.

Click to expand...

Yeah I just noticed the vendors are making the distiction now. To bad the the 10w is not priced proportionate to the 18w, meaning 40% less. LOL

clocker2 said:

You got the Temperpedic sample too?
I have a chunk sitting here that I plan on using for the next build...freaky stuff, isn't it?

Click to expand...

Hehe, I've got a chunk too. Thats why I'm not even thinking about mounting and vibration noises, only motor noise.