Dual Pumps D5: benefits

Associate
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Hi all, slightly noob question coming up. From reading up on the Single vs Double D5 pumps, there are various views as to:

  1. whether pump redundacy is a real consideration or not (single pump failure vs additonal points of failure in the additional loop connections of a dual pump system)
  2. whether an increased flow rate is actually worth it, due to apparent negligable cooling benefits this brings to the cooling ability of the loop
  3. the running speed of a single vs double, insofar as noise generation is concerned, when considering fans noise also (ie this may only be a noticable benefit if your system also runs quiet fans)

One aspect that is generally accepted as a genuine benefit is being able to run the loop at a lower speed for the same flow rate and pressure, and this therefore translating into a quieter system. Is this reduction in noise a genuine / practical / tangible benefit?

Seems to be a lot of cost and complexity for this privilege. Am speccing a sytem that aims to run cool, and quiet. So curious as to what the lay of the land is.

Any view here on this?

Cheers :)
 
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Man of Honour
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For the majority of setups a single D5 is more than enough. I do run a pair of D5's though because with over 10m of tubing my setup is anything but normal. Pump redundancy wasn't even a consideration as the res is right in front of me and I would know from the instant I started the pc whether the pump was running or not. With the length and complexity of my loop coupled with a very restrictive cpu block I decided from the outset that a pair of D5's was the way to go for me. Both pumps are running at maximum (setting 5) and I can't hear either of them (both sit on blocks of foam). From what I have seen and read flowrate makes very little difference to water temp and D5's are pretty quiet anyway so setting them low to make less noise doesn't make any sense in my case. If you want silence then carefully choose your radiator's and fans as they will make the biggest difference. If you can fit them consider using radiators that use 140mm fans over those that use 120mm fans. I have a pair of HWLabs Black Ice Nemesis GTX280 rads coupled with 8x Arctic Cooling P14 fans setup in push/pull mode and for all but the hottest weather can get away with running the fans at 780rpm which is just about silent and keeps my water temps in the low 20's (the rads are in a box on a windowsill sucking outside air through them).
 
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For the majority of setups a single D5 is more than enough. I do run a pair of D5's though because with over 10m of tubing my setup is anything but normal. Pump redundancy wasn't even a consideration as the res is right in front of me and I would know from the instant I started the pc whether the pump was running or not. With the length and complexity of my loop coupled with a very restrictive cpu block I decided from the outset that a pair of D5's was the way to go for me. Both pumps are running at maximum (setting 5) and I can't hear either of them (both sit on blocks of foam). From what I have seen and read flowrate makes very little difference to water temp and D5's are pretty quiet anyway so setting them low to make less noise doesn't make any sense in my case. If you want silence then carefully choose your radiator's and fans as they will make the biggest difference. If you can fit them consider using radiators that use 140mm fans over those that use 120mm fans. I have a pair of HWLabs Black Ice Nemesis GTX280 rads coupled with 8x Arctic Cooling P14 fans setup in push/pull mode and for all but the hottest weather can get away with running the fans at 780rpm which is just about silent and keeps my water temps in the low 20's (the rads are in a box on a windowsill sucking outside air through them).

Just go with everything PastyMuncher has said, 2 pumps in most cases is massively over engineering it at a premium
 
Soldato
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Good advise above.

For me, Dual D5 in serial worked a treat. Double the head pressure which for me was a must but I have a pretty massive and complex loop. External Rad, water then travels to PC which has 3 GPU blocks in parallel + CPU block. By doubling the head pressure in serial, saw a noticeable uplift in flow rate. Now flow rate is not to much of an issue once you get to a minimum level for 99% of builds, but in my case given the complexity of the loop, with not enough flow not all the GPUs get cooled. Partially self inflicted putting them in parallel for aesthetics rather then serial but by having a second D5 in series and seeing a noticeable uplift in flow rate (from a single D5) in my loop I saw proper cooling of the GPUs.

But yeah outside of this, in my other build which is more typical, single GPU / CPU / couple of rads (all within case or close too), then a single pump is perfectly fine.
 
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i bought a D5 pump/combo from EKWB for my first watercooled build and it was in an Evolv itx case (back when that was new maybe 8 years ago?) it still works now and it ran at full speed the whole time. i have had to change pump in my latest build (in an nr200 case) because it wouldnt fit and have gone to a corsair XD3 which i beleive is a DDC pump, the noise difference is night and day. i have to have this new pump at lower than 40% for the sound to be comparable to my D5 at full speed, any higher and its just so noisy.

so i cant for the life of me see how having 2 pumps running at a lower speed offers any sort of increased comfort when they are so quiet anyway.
 
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D5's back in the day were noiser, as were all pumps, now the noisiest thing in your case is likely to be the cheap rgb fans you have on your case. Or maybe that's just me,as I have all the expensive fans on my rads
 
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Just to be slightly against the grain here, I'm running 9 fans at 400 rpm and the single d5 is definitely the noisiest thing in the case at anything over 30% speed. With the pitch of the sound too it's pretty noticeable and annoying to me.

If you value silence and aren't deaf, I can't imagine running one at max speed with it in the same room.
 
Associate
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I am soooo glad I went for the dual pump option. I'm in a similar situation to @Hudzy. I have 9 140mm fans and at idle I can run them at low enough rpm to make them barely audible. Same with the pumps. During setup I experimented with a single pump and the noise needed for a decent flow would have driven me mad. Redundancy was a secondary benefit.
 
Man of Honour
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My pair of D5's (Aquacomputer VPP655 varios) are running at full speed and are both sitting on pieces of foam that you used to be able to buy for silencing HDD's (was it acoustifoam or something like that?) and they really are perfectly silent, no whine or anything.
 
Soldato
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D5's back in the day were noiser, as were all pumps, now the noisiest thing in your case is likely to be the cheap rgb fans you have on your case. Or maybe that's just me,as I have all the expensive fans on my rads

depends on fan speed.

i find just about any fan is inaudible under 1000rpm, where as my D5 pump can be heard above the fans at almost any rpm because its sound is a higher pitch than a fan
 
Soldato
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My pair of D5's (Aquacomputer VPP655 varios) are running at full speed and are both sitting on pieces of foam that you used to be able to buy for silencing HDD's (was it acoustifoam or something like that?) and they really are perfectly silent, no whine or anything.

why do you have 10 meters of tubing? I've got a one EK XE 360 and two EK PE 360's and my tubing is about 1.2 meters
 
Man of Honour
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Like I said, my setup is anything but normal. My radiators are in a filtered box on a windowsill at the opposite end of the room to my pc. The radiators are there so that they are sucking outside air through them which gives me extremely low temps.
 
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OK so I'm thinking I should go single D5 on a loop with 1x cpu, 1xgpu, and 3x360 rads. Yes there'll be some 90 degrees and 45 degrees fitting in there but it's not an "unorthodox" loop or massivley extensive. I want the sytewm to be near silent, which the D5s apparently are, and I can live without pump redundancy.
 
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Soldato
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Pumps are pretty reliable
But they can and do fail
Having a second d5 for redundancy
Is the way I go
Say your pump failed
Consider how soon can you get a replacement?
How easy is it to drain and replace?
How critical is not having your pc running?
With a second pump you can in the event of a failure
Choose when is suitable to replace the failed one
 
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I’ve seen a fair few builds with dual pumps in series in a loop, with a dedicated reservoir located somewhere on the loop.

But, has anyone tried to put dual pump/reservoir combo units in series on the same loop, by any chance?

Is this a mad idea? Would this add resistance vs dual pumps and a reservoir? Would it create any other issues?
 
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Soldato
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I had one fail on my recently, the white ball that sits on the shaft should be solid but its broke off sort off and now freely spins on it the spindle causing a racket when you turn it on. It is one of those pumps that i've had for nearly 10 years though so go figure.
 

V F

V F

Soldato
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I'm curious, are people running flow meters to check if their pump(s) are failing apart from the irregular noises when it's packing in?
 
Soldato
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I’ve seen a fair few builds with dual pumps in series in a loop, with a dedicated reservoir located somewhere on the loop.

But, has anyone tried to put dual pump/reservoir combo units in series on the same loop, by any chance?

Is this a mad idea? Would this add resistance vs dual pumps and a reservoir? Would it create any other issues?

If you mean 2 of something like this
https://www.overclockers.co.uk/ek-w...gb-pump-reservoir-combo-acetal-wc-9ws-ek.html
Yeah that's what I have in my loop
 
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