SLK-900 - 92mm fan!

TheMuffinMan · Post by **TheMuffinMan** » Tue Jan 28, 2003 11:27 am

No one seems to have mentioned it... http://www.thermalright.com/slk900.html

Absolutely sickeningly large!

powergyoza · Post by **powergyoza** » Tue Jan 28, 2003 11:49 am

Thanks for the link. Didn't know it was on their website - I still see no link on their homepage. FYI: I mentioned it here - http://forums.silentpcreview.com//viewt ... =7261#7261

EDIT: Nevermind. The homepage does have a link. It was the slk800 page that didn't have a link.

attnet · Post by **attnet** » Tue Jan 28, 2003 3:00 pm

Wow, that thing looks pretty big, especially if it can accomodate a 92mm fan! However, the bolt-through mounting seems like a bit of a pain. Any word on how this cools compared to the AX-478?

Post by **MikeC** » Tue Jan 28, 2003 6:25 pm

Guaranteed it will be better at all airflow levels that are practical -- ie. maybe with a Panaflo at 5V, the AX478 could have a wee edge, but if we're talking about temps beyond 60C in a P4 on a open test rig, it's not exactly desirable performance. At 7V, it will beat them all, is my prediction -- but probably only by a small margin. We're at the limits with conventional straightup HS & aircooling. Time to look for quieter higher airflow fans, IMO, and heatspreading heatpipe type technology in non-customized packages.

JarsOfFart · Post by **JarsOfFart** » Tue Jan 28, 2003 10:45 pm

NNOOO!!! My SLK-800 is no longer the best. I know longer am at the bleeding edge in at least one of my components.

Post by **Rusty075** » Tue Jan 28, 2003 11:14 pm

JarsOfFart wrote:NNOOO!!! My SLK-800 is no longer the best. I know longer am at the bleeding edge in at least one of my components.

Only one solution for that. Upgrade.

Storm · Post by **Storm** » Wed Jan 29, 2003 3:45 pm

fs and i just bought a slk-800 a few weeks ago

SilentButDeadly · Post by **SilentButDeadly** » Wed Jan 29, 2003 4:38 pm

I like the monster!
When the Barton 2500+ becomes available at a $75 price (or so) the 900 looks like the beast to cool it with a Panaflo 92mm at 7V. That should do it.

Post by **Ralf Hutter** » Thu Jan 30, 2003 5:03 am

Thermalright's even got a new SLK-800, called the SLK-800(A). Look at Newegg's page. Apparently it's got four extra fins, comes with two different sizes of fan mounting clips and a tube of some sort of thermal compound.

Captain Spaulding · Post by **Captain Spaulding** » Thu Jan 30, 2003 9:07 pm

Don't worry. Those "Hammer" CPU's that will obsolete everything you have apparently will require a heatsink of a completely different size. Talk about literally planned obsolescence.

jinu117 · Post by **jinu117** » Sat Feb 01, 2003 12:38 pm

I haven't had luck of finding it in any online store.... yet... (after searching through list of thermalright's official distributors)

morganw · Post by **morganw** » Wed Feb 05, 2003 4:27 pm

Looks like Heatsink Factory is going to get some soon.

If you believe this review (some don't buy the use of reference heat sources), the SLK-900 only does marginally better than the SLK-800 using the same fan.

I see the mounting system as an advantage- I was considering a Swiftech MCX462+ simply because I didn't want to worry about ~2 pounds pulling on 6 little plastic ears.

The SK-7 (which is US$25 vs. $36 for the 800 and $55 for the 900) comes in right behind the 800.

Comparing my present stock (retail) Athlon cooler which does 0.50 C/Watt vs. 0.25 C/Watt SK-7 + Tornado I see that the latter gets 1/2 the temperature rise whilst using a fan that does nearly 4x the CFM in free air (23 vs. 84).

That makes me wonder whether the surface area of the die (which is a constant) limits performance. Copper may do better than aluminum, but more air appears the largest factor.

Now running larger fans slower lets us get more CFM/dB, but there is a limit to this because no one seems to make fans that turn below maybe 1200 RPM. I have a 120MM Panaflo L1A case fan and with a rheostat adjusted so it always starts (about 6.5V when running), it's louder than an 80mm M1A controlled by a NoiseKiller (which has to have a similar minimum voltage because power-cycling the computer with the heat sinks still hot never results in a stall).

Now the 120mm is probably blowing more air than the 80, but unless I resort to PWM and growling, I can't get a quieter & slower 120mm. They just don't seem to be made.

I conclude that bigger is not better if you can't get the airflow to the minimum actually required. If an 80mm L1A at 7V on an SLK800 will keep my Athlon XP 1.4GHz cool enough, a 92mm L1A at 7V on an SLK900 is just going to be louder.

The SLK900 might be a good choice for using a duct from the case fan and reducing the total number of fans though.

Post by **MikeC** » Wed Feb 05, 2003 5:15 pm

morganw -- Agree pretty much with all your points.

If you believe this review (some don't buy the use of reference heat sources), the SLK-900 only does marginally better than the SLK-800 using the same fan.

I do believe it. I stand by my original comment earlier that we are at the limits for "standard" aircooled HS, and any additional gains are going to be very marginal.

For improved quiet performance, we need to look for ways to increase airflow w/o noise. The Panaflo L's 24 cfm airflow, if it could be had at 12 or 15 dBA instead of 21 dBA -- that would be a huge step forward. Even with watercooling, there's no avoiding the need for higher airflow, lower noise fans. Watercooling is a misnomer really. The cooling in the end is still being done by airflow across the radiator. Water is an extra intermediary step to transfer the heat more efficiently from the source to a large heatsink (the radiator); you could call the pump and water an "active heatpipe" of sorts.

SilentButDeadly · Post by **SilentButDeadly** » Wed Feb 05, 2003 5:20 pm

You could always put an 80mm fan on the SLK900,
The 92mm overhangs a little on each side of the heatsink, the 80mm would not do that and just push air through the fins. I think a 92mm Panaflo L would push more air at 5 volts VS 7 volts of the 80mm fan. Have been using two Panaflo L 92mm case fans for a few years, now they are controlled by the Antec "fan only" connectors off the power supply. Very quiet, no problems here!
Then again, the Vantec Stealth 80mm fan running at 12V is quiet enough for me so your mileage may vary.

korsch · Post by **korsch** » Thu Feb 06, 2003 4:05 am

I like the Panaflo L 92mm too. Very quiet at low rpms and capable of pushing decent air.

But some seem to be saying that a 92mm on the SLK-900 won't in fact provide a better cooling/noise ratio? I'm not sure why.

Even if the SLK-900 offers only marginal improvement on the SLK-800 or AX-478 using the same fan, would the fact that you can use a 92mm fan at lower rpm to achieve the same airflow and cooling also make it a quieter solution? Or is the issue that the 92mm may produce more air than an 80mm fan at a given rpm, but that doesn't necessarily translate into more cooling due to the large fan size in relation to the small size of the CPU and contact point with the heatsink? Not sure how clear that is, but obviously the benefits of increasing fan size relate to the size/surface area of the object being cooled: can a 20 foot fan cool a cpu better than a 120mm fan, or 80mm?

I'm not clear on this. Maybe this came up in the Zalman heatsink review when the 92mm fan was switched for an 80mm, I can't remember...

Post by **Rusty075** » Thu Feb 06, 2003 8:11 am

I think the change to through-bolting is the biggest improvement. For a heatsink that is approaching double the recommended max weight just using the lugs would make me very nervous.

jinu117 · Post by **jinu117** » Thu Feb 06, 2003 3:15 pm

Okay, finally figured out where they sell one.
svc.com has it for 49.99. (Gasp... that is more than what I paid for my Zalman 5700!)
My ultimate goal is to reduce the sound coming from CPU fan to be inaudible once it goes beyond two foot at 2 AM in my house. (Day time, you have exceptional hearing if you can hear the computer at all other than HDD)
I will be testing this with my Zalman 5700 using same fan (Vantec 80mm) to see if this is indeed more efficient. Another variation of thes I will be running is using the duct from Zalman 5700 and pulling air out of heatsink (I really think it is more efficient with my passive 9500 Pro and passive northbridge next to the CPU for over all temperature).
I ordered it now and priority shipping in state sounds to me arrival on monday or tuesday. I will definitely let you guys know.

Post by **MikeC** » Fri Feb 07, 2003 5:56 pm

It's doubtful that a low airflow 92mm will give any appreciable cooling improvement over a low airflow 80mm on the SLK900. The HS is not really THAT big; an 80mm will still hang over the edges a bit. A 92mm will hang over the edge more. The additional airflow of the 92mm will not go over/through the HS but around it, so I can't see how it would benefit. If you had an 80mm that sounded like the Panaflo at 6-7V but blew as much air as at 12V, then... well then we'd all be lined up to buy the thing!

Seriously guys, overclockers.com measures the advantage of the SLK900 over the 800 at 0.22c/w vs 0.23c/w. Admittedly, this is with a high speed high airflow fan, and the difference will probably be a bit more with a low airflow fan. But don't look for a lot in my review next week.

TheMuffinMan · Post by **TheMuffinMan** » Sun Feb 09, 2003 1:46 pm

Click here for a review of the SLK-900 (translated)

ez2remember · Post by **ez2remember** » Sun Feb 09, 2003 3:38 pm

MikeC wrote: Seriously guys, overclockers.com measures the advantage of the SLK900 over the 800 at 0.22c/w vs 0.23c/w. Admittedly, this is with a high speed high airflow fan, and the difference will probably be a bit more with a low airflow fan. But don't look for a lot in my review next week.

What interest me the most is the fact that it is for both Intel and AMD this time. I regarded the thermalright as one of the best HS but it was exclusively for AMD owners before. So I can't wait for the review, I think this will be the king of the Intel crown.

jinu117 · Post by **jinu117** » Sun Feb 09, 2003 4:35 pm

MikeC wrote:It's doubtful that a low airflow 92mm will give any appreciable cooling improvement over a low airflow 80mm on the SLK900. The HS is not really THAT big; an 80mm will still hang over the edges a bit. A 92mm will hang over the edge more. The additional airflow of the 92mm will not go over/through the HS but around it, so I can't see how it would benefit. If you had an 80mm that sounded like the Panaflo at 6-7V but blew as much air as at 12V, then... well then we'd all be lined up to buy the thing!

Seriously guys, overclockers.com measures the advantage of the SLK900 over the 800 at 0.22c/w vs 0.23c/w. Admittedly, this is with a high speed high airflow fan, and the difference will probably be a bit more with a low airflow fan. But don't look for a lot in my review next week.

The questionable thing is, how would this fare with Swiftech's MCX-4000 which are known to be decent at low RPM fan setting... (say about 10-15 cfm 80mm fan comparison).

Post by **MikeC** » Sun Feb 09, 2003 5:15 pm

I think this will be the king of the Intel crown....
...how would this fare with Swiftech's MCX-4000 which are known to be decent at low RPM fan setting...

Ah, the P4 app -- that will be an interesting question. I forgot about that. I guess it will double the review effort.

I won't be able to say against the MCX400 as I don't have one to compare but against the MCX462+, yes. I've mentioned this before, but the tighter pin layout since the MC462 makes the newer Swiftechs less effective with low airflow.