Iwaki Rd-20 / Rd-30 Pricing: Ordering Now Closed

[situman]

THese pumps are not good performers at 12volts right? I might have missed it, but how does it perform with a regular PSU?

[nikhsub1]

THese pumps are not good performers at 12volts right? I might have missed it, but how does it perform with a regular PSU?

They will not run much below 16-17v or so.

[epion2985]

They will not run much below 16-17v or so.

So at the lowest around 17v will the RD20 and RD30 run about the same as far as power drain, heat dump, flow and head?

Are there any negative effects to undervolting them or is it perfectly fine for the pumps?

[nikhsub1]

So at the lowest around 17v will the RD20 and RD30 run about the same as far as power drain, heat dump, flow and head?

Are there any negative effects to undervolting them or is it perfectly fine for the pumps?

They actually may run at lower voltage, the issue will be at what voltage will they start up at? Example; you start the pump at 18v then get it down to say 12v (can't go this low on my Meanwell), you turn the pump off at 12v. Will the pump restart with 12v? That is the question. To the first question the answer is simply no. The RD-30 will outperform (head + flow) the 20 at all comparable voltages. Heat dump will obviously be more with the 30 at all comparable voltages, how much I do not know.

Undervolting the pump will have only positive effects on MTBF, sort of like underclocking your CPU.

[MaxxxRacer]

Undervolting the pump will have only positive effects on MTBF, sort of like underclocking your CPU.

That right there makes the 30 more attractive.. are they the same size. i dont recall.

[epion2985]

They actually may run at lower voltage, the issue will be at what voltage will they start up at? Example; you start the pump at 18v then get it down to say 12v (can't go this low on my Meanwell), you turn the pump off at 12v. Will the pump restart with 12v? That is the question. To the first question the answer is simply no. The RD-30 will outperform (head + flow) the 20 at all comparable voltages. Heat dump will obviously be more with the 30 at all comparable voltages, how much I do not know.

Undervolting the pump will have only positive effects on MTBF, sort of like underclocking your CPU.

Well my biggest worry is the heat dump from the 30 over the 20. I will be undervolting wich ever I would have gotter.

I decided to go for the 30 because I can undervold it anyway and the price difference is tiny. But now I am worried if I undervolt the 30 to the point where it would run like the 20 under 20v it will put put out more heat then the 20 under 20v which would be running just as hard as the 30 under Xv. Or will it?

[nikhsub1]

Well my biggest worry is the heat dump from the 30 over the 20. I will be undervolting wich ever I would have gotter.

I decided to go for the 30 because I can undervold it anyway and the price difference is tiny. But now I am worried if I undervolt the 30 to the point where it would run like the 20 under 20v it will put put out more heat then the 20 under 20v which would be running just as hard as the 30 under Xv. Or will it?

Oh man, stop worrying! Im telling you the 30 is a better choice. But, don't believe me.

[Danger30Q]

Just read this whole thread through and I must say most people seem confused between the RD-20 or RD-30. I recommend that you listen to nikhsub1 and just buy the RD-30 for the extra $15. He says it's a better pump and that's final.

The real question is which converter or MeanWell PSU to use. I just ordered a RD-20 from a local distributor and I'm definintely not getting it as cheap as fareastgq is through his batch order. I think I'm going with the MeanWell S-145-24 and undervolt to about 19-21V. I also have the same Zippy 700W that fareastgq has but it's a $250 PSU that I'd much rather protect than a sub-$50 Meanwell. Plus, I'm running X1900's in crossfire and I could probably dedicate a PSU just to those monster hogs alone.

I honestly think that the RD-20 is overkill for just about all of us so no matter which pump you choose you're still getting a monster.