It is currently Thu Sep 18, 2014 5:53 am

All times are UTC - 8 hours




Post new topic Reply to topic  [ 4 posts ] 
Author Message
 Post subject: Do db ratings for products really mean anything much?
PostPosted: Fri Nov 22, 2002 4:07 am 
Offline

Joined: Sun Nov 03, 2002 4:38 pm
Posts: 25
Location: Norwich UK
Ok so That's a bit of a rhetorical question, but I'm currently building a second back-up PC that will be underclocked if anything to run it very quiet with fan cooling.

My main system is fully water-cooled featuring no fans at all, the only noise producing items are the single platter 40GB Seagate Barracuda IV hdd's rated by Seagate at 20db.

Having just purchased a couple of Papst 8412 NGL 80mm fans for the back-up PC build I'm surprised how noisy they are.

Specification :
Sintec Sleave Bearing for ultra-quiet operation
CFM = 19.4cfm
RPM = 1500
dBA = 12
Dimensions = 80x80x25

Ok so they are not noisy in the true scheme of things, but at their standard 12 volts input, sound quite a bit noisier than the 2 x Seagate Hdd's to me. Even when run at 7v I still think the Hdd's are very slightly quieter.

Maybe it is more the type of sound, for instance sometimes an old TV gets a component that whistles when it's first turned on, this can be very annoying and audible to a human, but probably not register much if at all on a db meter. This begs the question, truly how useful are db ratings when comparing quiet PC cooling products?


Last edited by BladeRunner on Fri Nov 22, 2002 8:08 am, edited 1 time in total.

Top
 Profile  
 
 Post subject:
PostPosted: Fri Nov 22, 2002 7:33 am 
Offline
SPCR Reviewer

Joined: Sun Aug 11, 2002 3:26 pm
Posts: 3998
Location: Phoenix, AZ
Until there's a standardized methodology for measuring the noise I don't think Db rating are very useful.

Particularly for products that are being marketed as quiet. It's too easy for companies to fudge the numbers in their favor. (Like doing sound measurements from over a meter away)

There needs to be an independent testing organization to produce standardized tests, sort of like an Underwriter's Laboratory for sound.


Top
 Profile  
 
 Post subject:
PostPosted: Fri Nov 22, 2002 8:05 am 
Offline

Joined: Sun Nov 03, 2002 4:38 pm
Posts: 25
Location: Norwich UK
I think you are right, and it's something the industry should take on board as more people are getting fed up with unwanted PC noise. Maybe an independent testing standard, something along the lines of current safety and interference testing that products have to go through with a sound level grading awarded. Still be difficult to get across noise type which can be more annoying than rated level all things being equal, but it would help make eduacted choices on real data.


Top
 Profile  
 
 Post subject:
PostPosted: Fri Nov 22, 2002 9:26 am 
Offline
Site Admin

Joined: Sun Aug 11, 2002 3:26 pm
Posts: 11853
Location: Vancouver, BC, Canada
HDD makers have adopted sound power & the dBA scale. You can accept HDD noise specs with some confidence. There is a question of understanding how to interpret sound power figures, but as a comparative scale, it works fine.

A few PSU makers actually provide reasonably good sound pressure (dBA@1M) stats, but most don't.

Fan makers are the worst, in general. The vast majority barely give you 1M readings, and always only without load, so the numbers ALWAYS look lower than in reality. Very misleading, as a result.

Of course, any product whose noise is mainly the fan and inexpensive (HSF), you can bet they NEVER really test them. Question of economics & perceived ROI. The vast majority of component MFGs still don't think there's any real gain in providing accurate noise stats (which will not be cheap if you have a big product lineup and/or one that changes all the time).

A contact at VIA recently lamented the incredible difficulty of trying to get across to case manufacturers for the Mini-ITX platform that noise is an issue, that quieter is better: despite pushing and prodding and direct demands from VIA, the case/psu makers continue to provide less than quiet solutions. It is a continuing challenge for VIA, who is alone among the bigger players in really championing quiet.

The reasoning for that is simple: with owenership of the C3, it is a viable marketing strategy for them. (I don't think you'd see them pushing quiet if the C3 was a hot but powerful monster like the P4s and XPs; they'd be right in there pushing power!)

I've said this all along: the only way that you'll see the industry make a wholesale change is if the market sends a clear (LOUD ;)) message that taps directly into $$ coffers. That's you and me and anyone who buys PCs & components. As long as people are buying/paying for loud things, they will keep making and selling them.

What can we do? Keep asking for quiet stuff, buy them and don't buy loud stuff, and persuade others to do the same. Esepcially in the corporate scene. Yeah it sounds evangelical. ("Let me in your house & I'll show you why your PC is noisy..." :) ) Too bad. That's just the way it is. No one else is going to do it.


Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 4 posts ] 

All times are UTC - 8 hours


Who is online

Users browsing this forum: No registered users and 2 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
Powered by phpBB © 2000, 2002, 2005, 2007 phpBB Group