The Slipstream800 really *IS* the sweet spot!

Felger Carbon · Post by **Felger Carbon** » Tue Apr 15, 2008 1:12 am

Neil Blanchard has posted several times that the 800RPM model is the sweet spot for Slipstreams. I decided to check up on him.

First, about equal airflow: all five Slipstreams share the same injection-molded hub/blade assembly. If they're rotating at the same RPM, then they're pushing the same air. Since I was only testing Slipstreams, I removed the sensor propellor from my fixture and just used the fixture as a simple fan holder.

Second: with the 500RPM model rotating at 500RPM, I experimented to find how far away from the fan the SLM could be and remain above the ambient noise level (28.6dBA at 1:30AM PDT). I quickly found out that I had to be at the minimum distance of .5" to be just barely above the noise floor. Ya can't fight city hall!

Results: the Slip500 read 31.5dBA, the Slip800 read 29.2dBA, and the Slip1200 read 30.6dBA - all at 500RPM as determined by my Extech stroboscope. You want more than 500RPM? You can't get it from the 500 model, so the 800 model still wins. (I hope you all know that ~30dBA at .5" is awfully, awfully quiet at 1 meter!)

Authority figure 1, Felger Carbon 0. Darn!

Bluefront · Post by **Bluefront** » Tue Apr 15, 2008 2:35 am

What in the Hell are you doing up this hour of the morning.....I thought only crazy people were awake before the birds?

Sweet spot or not......the 1200rpm version is the better deal. It can run slow enough to be almost silent, and yet blow enough air to be useful.

FartingBob · Post by **FartingBob** » Tue Apr 15, 2008 2:52 am

Yea id prefer to get the 1200rpm and undervolt it as needed, especially since my room gets very hot during the summer, i need something that can push some more CFM when required. But the 800 is very good if you dont want to have to worry about undervolting or varying speeds.

yamahaSHO · Post by **yamahaSHO** » Tue Apr 15, 2008 5:49 am

Agreed. I have 3 - 1,200 RPM Slip Streams undervolted in my P180B. Quiet, yet able to kick up the cooling capacity with a twist of a knob.

jhhoffma · Post by **jhhoffma** » Tue Apr 15, 2008 10:00 am

What? No love for me either? I'm a bigger Slipstream fanboy than Neil!!

thejamppa · Post by **thejamppa** » Wed Apr 16, 2008 10:25 am

500 or 800 RPM slipstreams for me. No need to do messy cabling with fancontrollers.

walle · Post by **walle** » Wed Apr 16, 2008 10:44 am

thejamppa wrote:...No need to do messy cabling with fancontrollers.

Agreed... itâ€™s an art form and should be done with the outmost care.

Brians256 · Post by **Brians256** » Thu Apr 17, 2008 1:49 am

Bluefront wrote:What in the Hell are you doing up this hour of the morning.....I thought only crazy people were awake before the birds?

I may be crazy, but I bet that Felger isn't.

I have discovered that birds are really loud in Klamath Falls. Those brown geese are all over the fields, and they gabble. But, I hear that they do taste well smoked...

foem · Post by **foem** » Fri Apr 18, 2008 4:55 am

thejamppa wrote:500 or 800 RPM slipstreams for me. No need to do messy cabling with fancontrollers.

A good mobo and software controlled 1200RPM slipstreams - quietness, CFMs when needed and no messy cabling or fancontrollers. The win-win-win solution. vOv

Ash · Post by **Ash** » Sun Apr 20, 2008 2:53 am

i cant find the 800's in the uk at all? everywhere i look they only seem to have 1200+ and 500's. anyone know where i can get the 800's in the uk.

also, are the 1200's as quiet as the 800 when undervolted to run at 800rpm aswell? and how about airflow?

if i cant get hold of the 800's then i will just have to do that but only if they are as effective.

DaveLessnau · Post by **DaveLessnau** » Sun Apr 20, 2008 4:19 am

Just to make sure, is the 800 RPM model the SY1225SL12L? As far as I can see, the model numbers ending in:

- SH are 1900 RPM,
- H are 1600 RPM,
- M are 1200 RPM,
- L are 800 RPM, and
- SL are 500 RPM.

Also, would this fan be better as a CPU cooler fan or as a case exhaust fan (or equally adept at both)?

EDIT: oh, are these open or closed corner fans?

Ash · Post by **Ash** » Sun Apr 20, 2008 11:24 am

yeh i think you are right, those are the codes for the different speed of the slipstreams.

anyone know where i can get these from in the uk?

so far only america, and i havent bothered to check if they deliver to uk or how much they would even charge, may end up costing more than the fans them selves.

i can only find the s flex, and a few of the other models in uk stores

AuraAllan · Post by **AuraAllan** » Sun Apr 20, 2008 11:50 am

Ash wrote:anyone know where i can get these from in the uk?

Quiet PC has 500, 1200 and 1900RPM Slipstreams available.

FartingBob · Post by **FartingBob** » Sun Apr 20, 2008 12:33 pm

I dont think anyone in the UK stocks the 800, at least i couldnt find any (had to go for the 1200 and undervolt more). Someone should buy them in bulk from the US (where they seem reasonably common) and sell them on ebay.

Plekto · Post by **Plekto** » Sun Apr 20, 2008 9:56 pm

I looked at the CFM ratings of the 800s and decided to get the 1200s instead. That way I can use them at full speed where I need them(Ninja) and at 9V or 7V when I want.(intake)

Ash · Post by **Ash** » Mon Apr 21, 2008 2:17 am

yep looks like no-one has the 800's in uk.

well is a undervolted 1200 still quiet as the 800 with similar airflow.

Post by **NeilBlanchard** » Mon Apr 21, 2008 9:40 am

Hello,

I believe that the 1200RPM starts at a very low voltage (<4v, or maybe even <3v?), and therefore, it can be run down to similar speeds as an undervolted 800RPM unit. Or, you can get the 500RPM and just run it from 9v-12v.

Fayd · Post by **Fayd** » Mon Apr 21, 2008 10:47 am

funny... i could still hear my 800 RPM scythe when i ran it at 12v :/

Iron_Dreamer · Post by **Iron_Dreamer** » Mon Apr 21, 2008 5:22 pm

After getting my hands on a pair of slipstreams today, I've come to wonder why these fans get quite the amount of praise that they do around here.

Both have some intermittent bearing noise, whereas all of the S-Flex fans I've used (all three speed grades, numerous of each) have had no bearing noise to speak of.

The 500 SS seemed only a touch less tonal in its' air noise than an S-Flex run at 500rpm. In open air for testing, the SF seemed to have a slight edge in airflow, although I suppose that could be simply the pattern of air coming off the blades in such a way that it felt like a stronger breeze.

I don't quite understand the love for the 800rpm SS, as at 800rpm it doesn't disappear in my room (S-flex disappears around 600-650rpm).

Have I just got a couple of "dud" slipstreams to have this bearing noise? It's not intrusive or anything, nor constant, but disappointing in comparison to the quality of the S-Flex bearings.

BTW when are we ever going to get some "official" SPCR measurements of the slipstreams?

jhhoffma · Post by **jhhoffma** » Mon Apr 21, 2008 6:00 pm

Here's the deal with Slipstreams. In a normal case environment, Slipstreams give more airflow per rpm than a traditional fan, S-Flex included. This means you can get the same airflow at a lower speed that a traditional fan. Lower speed = lower noise. I will say that I have experience a little more bearing noise than I expected with a couple of samples; one was so bad I had to RMA it. However, when undervolted these fans are plain and simple much quieter than any other fan at equivalent speed.

I also don't go by what a fan does in open air. I go by what the temps in my PC say with all things being equal. If I replace a 120mm Tri-Cool running on medium (1200rpm and NOT quiet) with a 1200rpm Slipstream running at 9v (~1000rpm) it's much quieter and my temperature are lower. Or I can put a medium speed Yate-Loon (running @ 5V or 860rpms) in the same position and then replace it with an 800rpm Slipstream and still get lower temps with less noise.

The proof, as they say, is in the pudding. If you feel your fans have a little too much noise to them, you may want to consider RMAing them, as sample variance is always a factor.

Post by **NeilBlanchard** » Mon Apr 21, 2008 6:24 pm

Hello,

If the bearing noise is light, then some have reported that it goes away after some use.

Fayd wrote:funny... i could still hear my 800 RPM scythe when i ran it at 12v :/

Nobody has said the 800RPM is silent at 12v. The 500RPM is very quiet at 12v.

Iron_Dreamer · Post by **Iron_Dreamer** » Mon Apr 21, 2008 8:09 pm

Hmm, well I replaced the S-flex I had around 500rpm in the lower half of my P182 with the 500rpm slipstream. HDD temps are up about 3C. Go figure.

Bluefront · Post by **Bluefront** » Tue Apr 22, 2008 1:15 am

Couple of possibilities.....your ambient temps are higher than when the S-Flex was in there. Or more likely.... your Slip-Stream cannot handle the airflow resistance in that particular location as well as the S-Flex.

Realize that different fans handle airflow resistance at various rpms, differently from one another. There's no hard and fast rule about the results you're seeing. Experimentation is the only solution. Results using one fan in my case (for instance), will surely be different from your own.

Ash · Post by **Ash** » Tue Apr 22, 2008 2:27 am

well how about the results shown here.

http://www.xbitlabs.com/articles/cooler ... up_16.html

and here

http://www.xbitlabs.com/articles/cooler ... up_17.html

good thing here is they have grouped the fans and results by the noise levels, obviously low noise means slower fans, that way people arent comparing low temps from high speed fans and low noise from slow fans.

they have a 'comfort' level if u like at around 34db, and there is only a 2db difference betweem the quietest fan being the noctua (based on results) and the noctua at a faster speed at the 34.7.

you can take you pick from any of the fans in between for low noise, but it looks like the ss 800 is a good choise, althogh the ultra kaza seems to give the lowest temps out of those quietest fans.

i agree the best way is to experiment yourself, but its not easy for some people including myself to purchase 5 different fans, test them, return them if possible without any questions or get lumbered with them.

Bluefront · Post by **Bluefront** » Tue Apr 22, 2008 3:24 am

Well you have several ways to get the best/quietest fan for your application....

1. Go by the mfg. specs and hype. (the worst way)

2. Go by reliable review sites like SPCR, or read up on owner's experiences.

3. Buy a bunch of the best fans using results from method #2, and try them out for yourself. (the best way, but obviously the most trouble and expense)

nutball · Post by **nutball** » Thu Apr 24, 2008 7:29 am

Well, I ordered five of the 800s from the US. Will be interesting to see how they pan out.

Ash · Post by **Ash** » Thu Apr 24, 2008 1:13 pm

Nutball, if you could let us know that would be great.

Iron_Dreamer · Post by **Iron_Dreamer** » Thu Apr 24, 2008 5:15 pm

Bluefront wrote:Couple of possibilities.....your ambient temps are higher than when the S-Flex was in there. Or more likely.... your Slip-Stream cannot handle the airflow resistance in that particular location as well as the S-Flex.

Well, it turns out the performance discrepancy I noticed was due to user error! I had it hooked up to a fan header which I did not realize was set up in speedfan, so the fan had been running much slower than intended. Now I am getting the same temps for my drives as I did with the S-Flex.

FartingBob · Post by **FartingBob** » Fri Apr 25, 2008 6:40 am

nutball wrote:Well, I ordered five of the 800s from the US. Will be interesting to see how they pan out.

Theres a few german sites that i found that offer shipping to the UK. Avoiding translators, PC-cooling.de sells them for a very good price and has a UK language option. Shipping is much cheaper than from the US as well.
Make sure you search for "slip stream" and not "slipstream"

2 800's with shipping to UK comes to just 28.50 euros or Â£22.40, which is only a few pounds more than youd expect to pay for buying them online from a UK based site.

nutball · Post by **nutball** » Fri Apr 25, 2008 7:14 am

FartingBob wrote:2 800's with shipping to UK comes to just 28.50 euros or Â£22.40, which is only a few pounds more than youd expect to pay for buying them online from a UK based site.

The five cost me $72 including shipping from the US, which works out about Â£7.45 each after it's been through my credit card. Maybe Â£8.55 if HMRC decide to sting me for UK VAT. That's assuming they arrive of course...

I guess that flying them across the Atlantic won't exactly be helping my carbon footprint though!

The Slipstream800 really IS the sweet spot!

The Slipstream800 really IS the sweet spot!