Scythe Ultra Kaze, I need some answers from actual users...

Farinorco · Post by **Farinorco** » Mon Feb 18, 2008 4:18 am

I'm about to build a case with MDF with a custom design to house a custom watercooling system with a quad radiator. I'm going to use three fans with it, the reason why I want to use a quad rad then is to give a greater airflow surface to each fan and therefore reduce the radiator air resistance. My goal is to use low noise fans with most optimized performance I can have.

Of course the other factor that I've considered is using high static pressure fans... and Ultra Kaze catched my eye. By the looks of it, they seem the ideal fans to suck air through a rad at 1000rpm or less... or maybe not.

I've seen other threads here about them and they seem to be louder than usual 1000rpm 25mm quiet fans. What I would like to know is exactly how much. I'm sure that an Ultra Kaze 1000 is gonna move more air through the rad than a Yate Loon @ 1000rpm / Nexus, but I doubt it does move more air than a Yate @ 1200/1300 rpm. If the Kaze is so noisy @1000 as the Yate @1200/1300 I don't see the advantage. And the same with a Kaze @800 and a Nexus, for example.

Could anyone that has used/tryed the Ultra Kaze 1000 tell me a little about kind of noise, intensity etc compared to slighly faster fans? For example, how it sounds compared to a Yate at 12v or a bit less, or which speed you have to run your Kaze to make a similar noise than a Nexus at 12v... etc.

Could anyone that has used/tryed that fans recommend these to me over some Yate/Nexus for my rad (excellent high static pressure fans considering they are 25mm and their speed)?

Lots of thanks for your help.

jhhoffma · Post by **jhhoffma** » Mon Feb 18, 2008 7:23 am

Why not try the Slipstream style (available in 500, 800, 1200, 1600, and 1900rpm versions)? The 800rpm and lower are known to be dead-quiet and the 1200rpm only slightly less so. They will perform much better through restrictions than standard 7-blade fans.

Farinorco · Post by **Farinorco** » Mon Feb 18, 2008 9:12 am

Wow! Is that really true? SlipStream are for sure superb fans AFAIK, but I'd thought that they're designed for more or less restriction-free situations... it's not that its design suggests a really good performance in a highly restrictive environment with its little motor (appearently designed to leave a bigger flow path through the fan more than to be strong) and its seemengly thin blades... but then its true that its blades seem to be more or less curved and well fitted to the edges of the frame... and they have nine of them

Since Scythe released both at the same time, I was completely convinced that they have decided to release a high restriction specialist fan (the Ultra Kaze) and a low restriction specialist fan (the SlipStream)...

I have been reading wonders about SlipStreams since then, but I fear the highly restrictive core of a radiator kills its flow or nulify its advantage (I plan to use a BI GTX 480, not exactly the less restrictive one

, but I hope it will be more than compensated by the 33% increased intake surface for each fan through the rad).

Are you sure that it's a better performer than a Nexus/Yate Loon at a given speed/noise intensity when operating through a so high restriction as a radiator core?

And do you think they would end up moving more air through the rad for a given amount of noise than a Ultra Kaze?

I should get used to not discard anything by its looks only

jhhoffma · Post by **jhhoffma** » Mon Feb 18, 2008 11:25 am

I can't give hard numbers, but in my limited experience with the slipstream, the fan overcomes backpressure more effectively than anything else at it's speed. Due to the low pitch and higher number of blades, I believe that each blade shares less of the load against the fan and is able to produce similar CFM at lower RPM.

I did a back-end experiment by blocking 1/2 of the exhaust of my case and measuring the speed drop between an 800rpm Slipstream and a YateLoon D12SL-12 running at 800rpm (via FanMate-2). I don't remember the numbers offhand, but I do remember the Slipstream barely slowed down at all, and the Y/L, quite a bit.

Chris Beard · Post by **Chris Beard** » Wed Feb 27, 2008 4:50 am

Only thing I have to add is that my slipstream fan (I only have one so could be sample varience) is louder at the same RPM than any of my Yate Loon 140mm fans.

jhhoffma · Post by **jhhoffma** » Wed Feb 27, 2008 6:33 am

Chris Beard wrote:Only thing I have to add is that my slipstream fan (I only have one so could be sample varience) is louder at the same RPM than any of my Yate Loon 140mm fans.

Louder how? Bearing noise or turbulence?

That usually would go contrary to common beliefs of fan noise. Bigger fans are quieter because they can run slower at the same CFM, not because they have any advantages at being quieter at the same RPM.

Like you said, it could be sample variance. Sample sizes of 1 have never proven anything to me except that I'm an idiot for thinking it valid.

Felger Carbon · Post by **Felger Carbon** » Wed Feb 27, 2008 8:17 am

Chris Beard wrote:Only thing I have to add is that my slipstream fan (I only have one so could be sample varience) is louder at the same RPM than any of my Yate Loon 140mm fans.

Did you mean to compare the 140mm YL to the 120mm Slipstream, or was that a typo?

DrCR · Post by **DrCR** » Sat Mar 01, 2008 2:34 am

Felger Carbon wrote:
Chris Beard wrote:Only thing I have to add is that my slipstream fan (I only have one so could be sample varience) is louder at the same RPM than any of my Yate Loon 140mm fans.
Did you mean to compare the 140mm YL to the 120mm Slipstream, or was that a typo?

Going 140mm isn't necessarily a bad idea given that Farinorco appears to be going for a shroud config. Kind of oddly presented though, true.

Farinorco, I would just go with a proper heatercore/rad to begin with, something thin and with a low density fin config. Cathar's or BillA's designs and resultant offspring are/were good choices for our sort of crowd. Not sure if there are anything that bests them nowadays as I've been out of the loop on WCing for a while.

A "triple" rad is going to be overkill for your setup unless perhaps you're, say, max OCing a Kentsfield with a triple SLI vid config and want to just shroud two Slipstreams @ <500rpm to it. In that case I would go with an "SLI rad" config (loi). Unfortunately though, if you're just starting now you've missed the golden age of WCing. DYI phase change could be a fun replacement though.

DrCR

dhanson865 · Post by **dhanson865** » Sat Mar 01, 2008 6:41 am

Felger Carbon wrote:
Chris Beard wrote:Only thing I have to add is that my slipstream fan (I only have one so could be sample variance) is louder at the same RPM than any of my Yate Loon 140mm fans.
Did you mean to compare the 140mm YL to the 120mm Slipstream, or was that a typo?

No that wasn't a fair test. The Slipstream has a higher CFM to RPM ratio than other 120mm fans but in fact it was moving more air than the 140mm yate loon at the same RPM. That surprised me as I thought it'd be closer to even or maybe even with the Yate Loon pushing more air.

So the question isn't how loud it is at what RPM, it is how loud is it at what CFM. So long as the two fans are pushing the same amount of air the quieter one wins and it is a fair fight.

Now the hard part is figuring out the CFM actually pushed for each of the fans in that comparison.

If you believe the specs the equal airflow test should be run with the slipstream 120mm near 1085 RPM vs the 140mm yate loon at 1400 RPM.

The slipstream 120mm is pushing 28% more air at the same RPM as the 140mm yate loon. Or put the other way to get the same air you have to run the Slipstream 120mm at 78% of the RPMs of the 140mm yate loon to get the same airflow.

For the math inmpared that is 28% more air at the same RPM or 22% lower RPM at the same air flow.

Of course the specs could be an apples to oranges comparison and those numbers may not be entirely correct but I think its clear that an equal RPM test is not supposed to be anywhere close on noise levels between these two fans.

dhanson865 · Post by **dhanson865** » Sat Mar 01, 2008 7:22 am

jhhoffma wrote:That usually would go contrary to common beliefs of fan noise. Bigger fans are quieter because they can run slower at the same CFM.

Like you said, it could be sample variance.

The traditional comparison is a 92mm Nexus vs a 120mm Nexus or 120mm Yate Loon vs a 140mm Yate Loon. Same blade design different size. (Nexus and Yate Loon being basically the same fan for purposes of that sort of comparison). More importantly when doing so you don't do it by RPM you do it by CFM

Take the Nexus series for example the comparisons are

120mm Nexus = 1000 RPM
92mm Nexus = 1300 RPM
80mm Nexus = 1500 RPM

You don't run a 80mm Nexus at 1000 RPM to compare it to the 120mm Nexus. If you did the 120mm would be much louder as it's moving much more air. No you generally realize that the 120mm Nexus does more work and is therefore more useful than the 80mm Nexus.

Code: Select all

Fan         Voltage Noise   RPM CFM
120mm Nexus    7v    19     680  27
 92mm Nexus   12v    21    1380  28

Bigger fan, roughly the same CFM, lower noise

Code: Select all

Fan         Voltage Noise   RPM CFM
 92mm Nexus    7v   <18     820  17
 80mm Nexus    7v   <18     840  10

Two fans of different sizes at about the same RPM but one is putting out way more CFM than the other. 70% more. The only reason you don't notice is because they are right on the edge of the noise floor. Double the RPMs on these two and you'll start to think of the bigger fan as noisier than the smaller fan if you only pay attention to RPMs.

The slipstream is in a whole other category when comparing noise to airflow ratios. Sample variance doesn't even need to come into play in comparing a Yate Loon of any kind to a Scythe Slipstream. They are obviously different enough in airflow ratings that you have to think of them differently than you do a run of the mill fan and you definitely can't just compare them at the same RPM.

Chris Beard · Post by **Chris Beard** » Mon Mar 03, 2008 7:45 am

Sorry - allow me to be clear. At starting voltages for the fans I own the 140mm yate loon is the quietest. The slipstream is louder. This is roughly the same RPM at around 300-350RPM.

dhanson865 · Post by **dhanson865** » Mon Mar 03, 2008 6:03 pm

Chris Beard wrote:Sorry - allow me to be clear. At starting voltages for the fans I own the 140mm yate loon is the quietest. The slipstream is louder. This is roughly the same RPM at around 300-350RPM.

Interesting and possibly valid observance.

Does it really matter at 300 to 400 RPM? Even if one fan is louder than the other can you hear it over the fan in a Seasonic PSU (120mm fan running around 4v? Or a 7200 RPM hard drive from any of the top 5 hard drive manufacturers?

At those noise levels I'd be wanting the one that pushed the most air and I'd ignore any noise difference unless it would stand out vs the other fans and hard drive in my PC.

Besides, if starting voltage is between 3v and 5v most people will never run their fan that slow. It's more common to see a fan run at 5v or 7v than to see it run below 5v.

Poodle · Post by **Poodle** » Tue Mar 04, 2008 12:26 am

The slip stream cuts the air more times/m resulting in a higher pitched sound at the same rpm to the YL but probably gets a gain of static pressure and thus a higher CFM in the right situation. So drop the rpm talk. Just compare CFM to noise. You will probably see the biggest difference in an environment with a high impedance.

Do like a load test or something at the same room temp and compare cpu temps to noise or something.

Chris Beard · Post by **Chris Beard** » Tue Mar 04, 2008 3:11 am

Poodle wrote:The slip stream cuts the air more times/m resulting in a higher pitched sound at the same rpm to the YL but probably gets a gain of static pressure and thus a higher CFM in the right situation. So drop the rpm talk. Just compare CFM to noise. You will probably see the biggest difference in an environment with a high impedance.

Do like a load test or something at the same room temp and compare cpu temps to noise or something.

Fair does. I don't measure the CFM as it's not really relivent in my setup - just some airflow is needed, not that much at all. Good luck comming to a conclusion OP.

fri2219 · Post by **fri2219** » Tue Mar 04, 2008 6:49 am

The Ultra Kaze 1000 rpm fan is the best fan I've ever used in terms of CFM/dB. The quality of the noise is low and steady.

I've stuck them in wherever they fit in my HTPC, Servers, and Desktops. I hope they turn out to be as reliable as the Nexus fans they supplanted. It doesn't hurt that they're less than half the price of the Noctua NF-P12 fan aimed at the same applications.

fri2219 · Post by **fri2219** » Sun Mar 23, 2008 2:11 pm

I've been very happy with my Ultra-Kaze 120mm fans, and have taken to placing them anywhere I can fit them in (with thermocouple based speed controlers), including my office box, my HTPC, and my compile and file servers.

For my ears at least, I like their sound better than the Noctua NF-P's and or Nexus/Yate Loons.