SP94 vs SLK948U vs. SLK947U vs SLK900U

Maurizio XP · Post by **Maurizio XP** » Tue Mar 09, 2004 3:23 pm

which one of theese? on a p4 2.8/800

And which fan (to keep at 5v)?

a papst 3412NGL or a noisblocker SE2?

PAPST:
92 mm x 92 mm x 25 mm
35.9 CFM
1950 RPM
23 dB(A)
1.2 Watt (0.1 A)

NOISBLOCKER:
92 mm x 92 mm x 25 mm
37.65 CFM
1850 RPM
22 dB(A)
0.83 Watt

Thank you for answering

jabbadegrassi · Post by **jabbadegrassi** » Tue Mar 09, 2004 4:16 pm

http://silentpcreview.com/article132-page1.html

The main difference between the SLK-series 'sinks you mention is pretty much just motherboard compatibility, you'll probably find that performance is so similar between them that you won't notice a difference. The SP94 garnering better performance than the SLK series, at a higher price. It comes down to economics, if you can afford the SP94, you'll get better cooling performance, if not, the SLK series will perform admirably. I'm not exactly boned-up on my 92mm fans of late, so I'll leave that question to another member.

If I'm wrong about any of this, please, someone step in and correct me.[/url]

Maurizio XP · Post by **Maurizio XP** » Wed Mar 10, 2004 3:15 am

I read that article but here in Italy the sp series costs less than a slk948u so I was a little confused

thank you for your answer

mond · Post by **mond** » Wed Mar 10, 2004 3:45 am

regarding fans, i would recomend you go with a quiet 80mm (eg. L1A) instead of 92mm. i was using a 3412NGL (on an 947 btw) for some time but switched back to the 80mm L1A which gives the same cooling at a considerably lower noiselevel. quiet a lot of airflow go to waste due to the proportions of the heatsink, so fandiameter/cooling will not be proportional with these heatsinks i think. also; a 80mm at a higher rpm than a comparable 92mm will have a similar noiselevel, but deliver more cfm at the center of the heatsink, and there is no linear proportionality between cooling and cfm at low airflows with the SLK's, eg. a 7v fan will cool much better than an 5v fan. and that at the expense of only a very slight increase in noise (again with the L1A as reference).
does this make sence? propably not. the point is that in my experience an 80mm will give the same cooling as a 92mm at a lower noiseleve.

Wintermute · Post by **Wintermute** » Wed Mar 10, 2004 4:57 pm

mond wrote:a 80mm at a higher rpm than a comparable 92mm will have a similar noiselevel, but deliver more cfm at the center of the heatsink

I am not too sure if I would agree with you here mond. If you look at 80mm and 92mm fans, I believe that it is the fan blade size that increases with size, not so much the hub's diameter and therefore the dead zone in the middle. What you mentioned about the Papst 92mm is interesting though. I was going to purchase that exact fan to use with an SP-94, but after hearing what you have said I am not so sure anymore. I am trying to figure out what to use now. Thanks for the heads up.

jabbadegrassi · Post by **jabbadegrassi** » Thu Mar 11, 2004 12:24 am

Hey, I'm Italian/Canadian, cool. Anywho, if you can get the SP series, go for it, I know I would if I found it cheaper. As for fans, there is much debate here over the 80vs92mm as a cpu cooler. If you can find the fans cheap enough, why not try both? See which gives you the best results. After all, no matter how much we may argue on these boards, all that matters is that you're happy with your rig. Whether you do it with an 80mm fan or a 92mm fan...

Wintermute · Post by **Wintermute** » Thu Mar 11, 2004 1:24 am

I wonder if the Thermaltake A1442 Ducting Mod would work very well on the SP-94.

jabbadegrassi · Post by **jabbadegrassi** » Thu Mar 11, 2004 2:17 am

Probably not, since the fan retention clips that thermalright makes would be pretty much incompatible, so you'd have to make your own. I would be interested to find out if it benefits however...

civic5zigen · Post by **civic5zigen** » Fri Mar 12, 2004 2:47 am

You can use the Thermaltake ducting, I am using it now on my SLK800 with panaflo H. Is there any real differences between SLK800 then the SP or SLK9xx other then it fits 92mm fan? If that's the only differences then it makes no sense for me as I can use 92mm on my SLK800 as well. My HSF is still the louest in my system since OC my rig so much so I am looking for a better solution? So can someone tell me any benefit I would get for upgrading to SP or SLK9xx?

mond · Post by **mond** » Fri Mar 12, 2004 4:59 am

Wintermute, i am unsure about the difference in deadzone of a 80mm compared to a 92mm, it might have some importance, but it was not really what i was refering to. my point was that if a 80mm and a 92mm fan are delivering the same airflow, the 80mm will deliver more of it to the center of the hs, that should be obvious. this should especially be true for panaflos because they have a highly directed (or "tunneled"...) airflow. so there will be more cfm going over a the finarea at the center. this will give much better cooling with the slk's. also, as said, more of the aiflow will go to waste with a 92mm because of the dimmensions of the thermalright heatsinks.
and btw, this is subjective, but the 92mms i have tried (papst and panalflo) all have more caracteristic motornoise than the L1A. so delivering the same cfm, a 80mm might "woosh" more than a 92mm but the 92mm will "click" more, and this is by far the most anoying noise imo. the panaflo 92mm's are totally unacceptable as far as clicking goes, not silent in a in any way, at any voltage . imo

cosmo3 · Post by **cosmo3** » Fri Mar 12, 2004 6:44 am

I have tried 80mm and 92mm fans on these heatsinks and I get better temps with the 80mm fans. I would not have beleived it but I can use a lower cfm 80mm fan and get better temps than with a higher cfm 92mm fan. Even at the swiftech web sight it looks like that is the case also on their new P4 heatsink as a 80 some cfm 80mm fan cools better than a 119 cfm 92 mm fan.

Wintermute · Post by **Wintermute** » Fri Mar 12, 2004 9:14 am

What you guys are saying about the 92mm fans makes sense. So mond, are you using a L1A now or are you using a different 80mm fan (and at what voltage)? I was considering trying out an 80mm with a little more airflow than the L1A (gonna try and OC a little bit) on a SP-94. This whole quest for silence has really turned into a disease.

mond · Post by **mond** » Fri Mar 12, 2004 10:26 am

i am using the 80mmL1A now yes, the 92mm papst is used as a case fan@5v where it's pretty quiet. the L1A on the slk-947 is at about 7v, [email protected], full load @ ~60 degress, 54 with 2xFAH and idle around 37. at 5v th temps are much higher, this was also showed in the big HS roundup lately (i think the article was originally a review of the new intel coperbase hs), that the slk don't cool well with really low airflow, apparently the AlCu7000 is far superior at low airflow.

civic5zigen · Post by **civic5zigen** » Fri Mar 12, 2004 3:19 pm

I currently have the H version of panaflo 80mm running off my Sunbeam Reheous. If there any differences in terms of noise if I run the H ver at the same CFM as the L ver? Would the H ver still make more nosie then the L ver even at the same CFM due to different construction?