Passive heatsink for underclocked XP-M (socket A)

slem · Post by **slem** » Mon Jan 17, 2005 2:53 pm

Hello!

I'm planning to build a single fan HTPC for my living room, and now I'm looking for a suitable heatsink. Ideally it should be able to cool the CPU passively at 1GHz and undervolting, but also allow attatchment of a fan if I should want to run the CPU at default speed.

The specs will be the following:
CPU: AMD XP-M 2200+, 35 Watt
PSU: SeaSonic Super tonado 300Watts
MB: Abit NF7-S2G (passive NB)
GPU: Matrox G400

I will use a standard ATX case so room is not a problem. The bottom mounted 120 mm fan on the PSU will be used to draw air over the heatsink and a 80 mm hole will be dremeled near the bottom of the front of the case to provide ample airflow. Possibly I will duct air from the front intake further into the case to maximize airflow over heatsink

Any comments and suggetsions are welcome,
Thank you!

Edward Ng · Post by **Edward Ng** » Mon Jan 17, 2005 2:58 pm

I nominate Thermalright SI-97.

mr pink · Post by **mr pink** » Mon Jan 17, 2005 3:08 pm

zalman copper flower.

Jordan · Post by **Jordan** » Mon Jan 17, 2005 3:38 pm

Edward Ng wrote:I nominate Thermalright SI-97.

Agreed 100%! I will never buy another Zalman fan/HS combo again. Don't get me wrong, the noise/performance ratio was excellent but the proprietary fan is far too limiting for the enthusiast.

mathias · Post by **mathias** » Mon Jan 17, 2005 4:10 pm

Jordan wrote:Agreed 100%! I will never buy another Zalman fan/HS combo again. Don't get me wrong, the noise/performance ratio was excellent but the proprietary fan is far too limiting for the enthusiast.

What are you talking about? Maybe it's limiting for the semi enthusiast, but they're definitly replaceable. Zalman fans undervolt a lot anyway

And zalman flowers(CNPS 2000-6500) aren't stuck to any fans, ironically you can use almost any size fans with them.

If anyone deserves blame for being propretiary about their fans, it would be arctic cooling.

mr pink · Post by **mr pink** » Mon Jan 17, 2005 4:49 pm

I think jordan is thinking of the newer zalman models. The flowers will accept any fan, period.

flyingsherpa · Post by **flyingsherpa** » Mon Jan 17, 2005 5:30 pm

well, call me a pessimist but i just don't think it's a great idea to do a passive cpu setup. any of the spcr recommended heatsinks that will take a fan like an 80mm panaflo at 5V will add no noise to your system yet allow you to run the cpu at stock speeds safely. there is just such a big difference in cooling with a small amount of forced air vs relying on case airflow and convection... so you get a big cooling advantage for no noise*. i just don't see the point of risking anything by going passive.

*let me qualify the 'no noise' for the purists

: an 80mm panaflo at 5V inside a case is essentially inaudible. it is certainly quieter than any 3.5" HD i have ever heard. i have several systems running 5V panaflos on the HS and the only noise i ever notice is from the de-coupled samsungs in those systems (and that is only late at night if i get close to the case).

so unless you plan on using 2.5" HDs in that thing, keep it simple and use an inaudible fan.

my .02

Jordan · Post by **Jordan** » Mon Jan 17, 2005 5:47 pm

Yeah I was thinking of the newer ones. To me THEY are the flower coolers (i.e. round) while the older ones are the fan (as in japanese/chinese style women's fans) like coolers.

"What are you talking about? Maybe it's limiting for the semi enthusiast, but they're definitly replaceable"

If you're referring to the CNPS7000 like I originaly was thinking of then why bother with it when the Si-97 is more efficient and lighter anyway and would save you money and hasle? Better to be warned before buying it than after.

mathias · Post by **mathias** » Mon Jan 17, 2005 6:17 pm

Jordan wrote:Yeah I was thinking of the newer ones. To me THEY are the flower coolers (i.e. round) while the older ones are the fan (as in japanese/chinese style women's fans) like coolers.

But, at 150g, the CNPS 3000 is actually light as a flower.

Fan seems like an inapropriate name for a heatsink. Maybe it would be less confusing to find types of flowers that look like the two heatsinks? If you refered to the 7000 as a tulip, it would be unambiguous.

Jordan wrote:If you're referring to the CNPS7000 like I originaly was thinking of then why bother with it when the Si-97 is more efficient and lighter anyway and would save you money and hasle? Better to be warned before buying it than after.

Well, yeah, it did save me money and hassle, I got my SI-97 for only $42 canadian (19 pounds), and I can have the fan blowing upwards to get the heat out of the case more directly(though I haven't really tested if it actually is doing so).

But the CNPS is still a decent option(even if blows air all over the case), especially for people who can't get an SI-97 or can't get it at a decent price, and you seem too harshly critical of zalman. And the basic design is good, it ported to video cards well where, ironically, it has the advantage of switchable fans, low weight and ease of installation over AC silencers.

Edward Ng · Post by **Edward Ng** » Mon Jan 17, 2005 6:20 pm

Yes and no; the only Zalman sinks that would measure up to SI-97 have to be the 7000s and 7700s (beating SI-97, of course); the 6X00 and lower models do not have the cooling capability of SI-97, and some models still weigh more than SI-97 to boot.

-Ed

Tiamat · Post by **Tiamat** » Mon Jan 17, 2005 6:28 pm

Edward Ng wrote:Yes and no; the only Zalman sinks that would measure up to SI-97 have to be the 7000s and 7700s (beating SI-97, of course); the 6X00 and lower models do not have the cooling capability of SI-97, and some models still weigh more than SI-97 to boot.

-Ed

Also, the Zalman 7700 for sure is totally not recommended (if it is even compatable in the first place) to run on the AXPs since they have no integrated heat plate. With the SI-97 costing 35$, I would go with that.
In addition, running passive might be too risky. In the summer time, the rise in ambient (depending where you live) might be enough to fry the cpu. If you can, placing a Nexus at low voltage in the back might help, it will also help in general cooling by drawing even more air from the front.

mathias · Post by **mathias** » Mon Jan 17, 2005 6:38 pm

How about an Scythe NCU-2000 or an Aerocool Ht-101?

Jordan · Post by **Jordan** » Mon Jan 17, 2005 6:39 pm

mathias - I like your thinking on the Zalman HS naming

"you seem too harshly critical of zalman. "

They are a fantastic all in one solution. I just no longer think that's the way to go. When I was looking into HSs it was easily the best around so I don't regret it as such. But given the choise NOW I'd go for the SI-97 hands down.

slem · Post by **slem** » Tue Jan 18, 2005 12:46 am

Seems i should go with the SI-97. I was looking at the Scythe NCU-2000 but here in Sweden it's not advertised as a Socket A heatsink. I have been looking at the Aerocool HT-102 (can't find the 101 here). As the heatsink will be mounted pretty close to the bottom mounted 120 mm exhaust fan on the PSU I figured a high profile would be a good thing, getting more air through the fins that way. Also a fan can be mounted on the side of the aerocool, pushing air into the exhaust fan, rather than pushing air in all directions as with a "top" mounted HS fan.

Any thoughts?

Concerning fans, is the 80 mm panaflo L1A the way to go?
Papst fans seems to be favored here in Sweden, the 8412NGLE is claimed to do 19,4 cfm at 12 dBA

Pilot · Post by **Pilot** » Tue Jan 18, 2005 3:02 am

In fact, it is what I planned for my computer. I reckoned that a SI-97 under my PSU 120mm fan would leave a 10mm clearance.
As I have a A7N8X, the socket orientation is ok.

First i will try to run it "passively" (with no cpu fan) to see if the sucking of the psu fan just on the rad is sufficient. Otherwise ;o( i'll go for a fan.

I also have a 80mm noiseblocker s2 (poor choice) in the front of my case, but even at min speed, and soft mounted, it is still the noisiest component of my case. My fortron also is noisy as it is unmodded : due to the aforementionned dimensions "issues", i cannot offer it.

slem · Post by **slem** » Tue Jan 18, 2005 4:12 am

In fact, it is what I planned for my computer. I reckoned that a SI-97 under my PSU 120mm fan would leave a 10mm clearance.
As I have a A7N8X, the socket orientation is ok.

Yes, with the NF7-S2G the socket orientation is ok for SI-97 too. I don't know exact clearence between PSU and HS but it will not be very much, 20 mm or so at most. I chose to stay away from Asus mb's since they do not undervolt. I plan to build this box with a XP-M to make it as silent, cool and cheap as possible to run since it probably will be running 24/7.

Pilot · Post by **Pilot** » Tue Jan 18, 2005 4:31 am

I chose to stay away from Asus mb's since they do not undervolt.

Sure, I would also stay away from my mobo, but it happens to be the one I own. It is already a miracle I can install the SI-97 in the same case as the psu ;o) as the chipset is on the very edge on the mobo. Actually, I'm still not sure it will fit without any cutting / folding ... brute force.

So I try to turn this weakness into a strength. Is the sucking effect is not sufficient, i'll try a ghetto duct to force the air passing through the rad before getting into the psu.

I'll publish my results when I have it : on friday.

Pilot · Post by **Pilot** » Fri Jan 21, 2005 2:44 pm

I've just installed my SI-97. The heatsink setup by itself was quite easy, but i had to cope with my case : i could not install the heatsink without removing the psu, but if i removed my psu and installed the heatsink, i would not be able to put the psu back ;o).

I finally managed to have both by sliding the psu aside.

Now for the temps :
35°C read when I had 36°C before (other heatsink, not stock, copper with heatpipes, don't know its brand).
(system has been on for more than 1 hour, running winamp and other not cpu intensive progs)
softcooling is on and the proc is @1250.

1°C seems not a great improve, but I have to be more precise : the cpu is running passive while it didn't before the swap.

Later on, I will put a fan on it to be kicked on (speedfan) for safety reason when i play games.

For the moment, the only noise is the air blown by the fortron at min speed whose fan is at less than 7mm from the SI-97 (so it is not actually passive ;o) )

daba · Post by **daba** » Fri Jan 21, 2005 3:00 pm

>> 1°C seems not a great improve, but I have to be more precise : the cpu is running passive while it didn't before the swap.

That's a huge improvement from an actively cooled heatsink to a passively cooled one! I remember when I ran my 3.0C passive, it was 42C idle with the XP-90, whereas now with a Nexus 92 it runs at only 30C idle.

Tibors · Post by **Tibors** » Fri Jan 21, 2005 5:05 pm

You might want to check (and report) your temps when you put on the fan, because a non running fan will actually block a part of the airflow currently going through the HS.

One thing you might also want to test, is always running the fan on the SI-97. But running it so slow you can't hear it over the noise the PSU still makes.

TheWesson · Post by **TheWesson** » Fri Jan 21, 2005 11:32 pm

passive blowhole next to the HS, all other fans to exhaust ... ?

thus, HS will be bathed constantly in cool (but not very fast) room air.

Pilot · Post by **Pilot** » Sat Jan 22, 2005 1:11 am

Actually, with my old HS, i had my fan spinning at only 50%, and running it at 100% would lower temps to 31. HS was an heavy all copper one with very fin blades oriented to high speed fan.

I had differences in efficiency only when pushing my CPU. I guess that heatpipes and heat transfer hardly don't work at low temps. I have to make a bench of cpu intensive tests.

Tibors, I thought about it but maybe it won't be the case as the airflow is along the HS, and non through it. See ? Thus, maybe having a stopped fan on the HS would duct even more airflow along the HS...
Enough of "maybe", i'll try and post my results.

SometimesWarrior · Post by **SometimesWarrior** » Sat Jan 22, 2005 3:49 am

Edward Ng wrote:I nominate Thermalright SI-97.

Question: why the SI-97 and not the XP-90?

Tibors · Post by **Tibors** » Sat Jan 22, 2005 4:31 am

SometimesWarrior wrote:Question: why the SI-97 and not the XP-90?

Because the XP-90 doesn't fit on socket A.

Edward Ng · Post by **Edward Ng** » Sat Jan 22, 2005 11:28 am

SometimesWarrior wrote:
Edward Ng wrote:I nominate Thermalright SI-97.
Question: why the SI-97 and not the XP-90?

XP-90/-120 only work on Sockets 478, 754, 939 and 940.

-Ed

Pilot · Post by **Pilot** » Sun Jan 23, 2005 6:53 am

So i've been through some experimentations :
With a ghetto paper duct on the psu : the airflow is forced along the SI-97 and temps are now 40 on full (cpuburn) and as low as 29 when playing music.

There is only the psu fan spinning but it stays at min speed, the psu doesn't get warm enough.

When i have a bit of time, i will put a fan as intake to keep the HD cool . By now its temp is 40 (max), so no need to hurry. I'll build a cage with alu spares. I'll provide photo later on.