Passive Scythe Ninja Mini on AMD X2 4800+ (65W)

Kreed · Post by **Kreed** » Tue Oct 16, 2007 8:15 pm

Do you guys think it's possible to passively cool an undervolted AMD X2 4800+ (65W version) using a Scythe Ninja Mini housed in an Antec NSK3480 case?

There are currently two Brisbane AMD X2 4800+ on the market, one based on the G1 stepping and the other on the G2 stepping:

http://products.amd.com/en-us/DesktopCP ... d=44&id=45

The one based on the G2 stepping has a higher stock voltage. So perhaps it has more potential for undervolting.

Post by **MikeC** » Tue Oct 16, 2007 9:56 pm

You know, you really have to think about what "passive cooling" means. In absolute terms, it means you rely only on convection, no forced airflow. That means no fans at all anywhere nearby.

My answer to your question if "passive cooling" is correctly defined, is... no. Not inside the case, not if you ever push it to high load, which almost everyone does at least some of the time.

But the widely accepted definition of "passive cooling" is that it means there's no fan directly on the heatsink. Never mind that there's a fan that COULD go on the heatsink just an inch or two away -- it's still not on the heatsink. If this is your definition of "passive cooling", then it's obvious -- the answer is... sure, why not?

The bottom line, imo, is that the question is moot. As long as you have one fan in there making some noise, whether you have a second fan making as little noise doesn't matter. There's no real perceived acoustic benefit to one versus two if both fans are really quiet -- the difference will easily be lost in the ambient or in the noise of other components such as the HDD and the PSU fan.

There probably isn't much cooling benefit either, not unless you run the system hard all the time.

Kreed · Post by **Kreed** » Wed Oct 17, 2007 12:10 am

Thanks for your response Mike. If there is no real perceived acoustic benefit when a case fan is present, then i might as well go with a cheaper HSF such as the CoolerMaster Hyper TX (AMD) or the Arctic Cooling Freezer.

jessekopelman · Post by **jessekopelman** » Wed Oct 17, 2007 12:23 am

MikeC wrote:As long as you have one fan in there making some noise, whether you have a second fan making as little noise doesn't matter. There's no real perceived acoustic benefit to one versus two if both fans are really quiet

I'd claim that two fans can actually be quieter than one. Let's say a second fan let's you run each at 80% the speed of a single fan. Two identical fans should produce 3 dB more noise than one, but a 20% reduction in speed should reduce noise by almost 6 dB -- Net change is almost 3 dB less noise. Now, 3 dB isn't much of a change (if -10 dB is half the perceived loudness than -3 dB is ~ 81% the perceived loudness), but it is at least a change in the right direction. By the way, I just tried this experiment. I put in an Akasa Evo120 heatsink and tried it with only the case exhaust running at 950 RPM. Then I added an identical fan to the heatsink and set them both to 750 RPM. There seems to be slightly less noise (certainly no more noise) and CPU temps dropped about 4C.

Bluefront · Post by **Bluefront** » Wed Oct 17, 2007 1:54 am

Keep in mind that with two fans, rather than one, you have twice as many bearings and their associated noise, and two times the possibility for fan vibrations to transferred into the case frame.

Then you have a second set of wires to deal with, and twice the chances that there will be a connection failure......and maybe you'll need another fan controller.....etc.

IMHO.....get one quiet fan. Arrange it to do the work of two or more fans.

Post by **MikeC** » Wed Oct 17, 2007 6:46 am

The comments by Bluefront and jessekopelman both have merit, and I have to admit I've argued both positions in the past.

The key here is to look at the specific details -- in this case, a 65W AMD X2, Ninja Mini, and a 120mm fan.

It's possible that jessekopelman's comments have more relevance here simply because the Ninja Mini isn't quite as good a cooler as the Ninja, and perhaps a 120mm fan at minimal noise / airflow wouldn't quite be cool enough. It's hard to say, but easy enough to experiment, and then add the supplied stock Scythe fan at minimal speed later if necessary.

If the cooler was a Ninja, I'd say you'd get acceptable cooling with just the case fan at min speed (typically ~700rpm or ~7V with a Nexus 120).

btw, I think a Ninja would fit in a NSK3480. The Ninja stands about 5.8" tall, while the width of the NSK3480 is 7.8"... The official price difference is just $5.

Kreed · Post by **Kreed** » Wed Oct 17, 2007 7:26 am

MikeC wrote: If the cooler was a Ninja, I'd say you'd get acceptable cooling with just the case fan at min speed (typically ~700rpm or ~7V with a Nexus 120).

btw, I think a Ninja would fit in a NSK3480. The Ninja stands about 5.8" tall, while the width of the NSK3480 is 7.8"... The official price difference is just $5.

I did initially consider the Ninja, but had some concerns about the Ninja's heatpipes touching the nearby RAM or Capacitors as discussed in this thread:

viewtopic.php?t=43699

Post by **MikeC** » Wed Oct 17, 2007 8:16 am

Kreed wrote:I did initially consider the Ninja, but had some concerns about the Ninja's heatpipes touching the nearby RAM or Capacitors as discussed in this thread:

viewtopic.php?t=43699

I suppose this is a concern. I have used the original Ninja on many boards. Touching the RAM didn't seem to cause any problems, IRRC, and caps could often be pushed & moved a mm or two if necessary. In any case, if fit on the motherboard is an issue, then surely this must be addressed. It depends on the motherboard.

puddnhead · Post by **puddnhead** » Wed Oct 17, 2007 12:18 pm

MikeC wrote:The bottom line, imo, is that the question is moot. As long as you have one fan in there making some noise, whether you have a second fan making as little noise doesn't matter. There's no real perceived acoustic benefit to one versus two if both fans are really quiet -- the difference will easily be lost in the ambient or in the noise of other components such as the HDD and the PSU fan.

You can have a 120mm fan in your case, but with a mini ninja you are not going to get one on the HS, you'd need 92mm. So you are saying that 1 120mm fan + 1 92mm fan (even a quiet one) is not imperceptibly louder than just the 120mm fan?

Post by **MikeC** » Wed Oct 17, 2007 12:52 pm

puddnhead wrote:You can have a 120mm fan in your case, but with a mini ninja you are not going to get one on the HS, you'd need 92mm. So you are saying that 1 120mm fan + 1 92mm fan (even a quiet one) is not imperceptibly louder than just the 120mm fan?

If the 120mm fan is the Antec tricool at low, a Nexus 92 at 7V will not be heard over it; it will make no perceptible difference. Yet at 7V, it'll probably drop the CPU temp by at least 5C, maybe even 10C, compared to just the case fan alone.

The Tricool measures 20 dBA/1m in free air, but mounted inside a case, the wooshing of airflow and the air resonance of the case itself probably adds 2~3 dBA.

If the case fan is a Nexus 120 at 7V, a Nexus 92 at 7V might or might not make an audible difference.

But now, the stock Earthwatts 380 psu probably becomes the main limiting factor. It idles in the case at 21~22 dBA/1m. It's audibly noisier than a Nexus 120 at 7V.

btw, all this is very fresh in my mind because we're working on a 3480 review right now.

jaganath · Post by **jaganath** » Wed Oct 17, 2007 1:43 pm

we're working on a 3480 review right now.

awesome!

Kreed · Post by **Kreed** » Wed Oct 17, 2007 4:52 pm

MikeC wrote:
puddnhead wrote: But now, the stock Earthwatts 380 psu probably becomes the main limiting factor. It idles in the case at 21~22 dBA/1m. It's audibly noisier than a Nexus 120 at 7V.

That's a bit disappointing. I was hoping it would be a bit quieter. On the last PC that I had built for my parents, I used an NSK3400. The PSU on that case was efficient, but noisy (relative to say a Seasonic PSU). So, I swapped the PSU fan with an 80mm medium speed Panaflo. I can now barely hear it. With the EarthWatts 380 PSU on the NSK3480, I was hoping a fan swap wouldn't be necessary.

Getting back to the topic at hand, I intend on using a 120mm Nexus (undervolted to 7-8 Volts) as a case fan. The CPU will either be a BE-2400 (if it's available) or a Brisbane 4800+. Both should be around the same price. With all the arguments put forward so far, I think the decision to go fanless with the heatsink is a flip of a coin. On the PC I built for my parents, the Asus M2A-VM HDMI motherboard doesn't seem to be able to reduce the speed of the fan on the heatsink (Arctic Cooling Alpine 7) below 900 rpm. Whilst it is quiet, I can still just hear it. This is why I am thinking about a fanless HSF this time round. Granted, I will be going with an Abit AN-M2HD mobo, which might be better at controlling the CPU fan speed.

andyb · Post by **andyb** » Wed Oct 17, 2007 5:21 pm

we're working on a 3480 review right now.

Interesting case (didnt know it existed 5 mins ago). Apart from your comment about the PSU being noisy (21-22 Db is outragous

) I noticed the huge open vent for the PSU, and thought that this case could make a low power PC very easy.

Antec 3480.
mATX Integrated graphics mobo.
Ninja (or Mini if it doesnt turn out to fit).
PICO PSU in the PSU bay.
2.5" HDD in the psu bay.
An even quieter fan perhaps.

A 1 fan system would be very easy to achieve and it wouldnt even need to run fast as there would be no obstruction from the front to the back of the case if there are no add-in cards or HDD's to get in the way and add heat to the area.

If a 45W CPU was used with a Ninja I would say that a 120mm Nexus would keep the temps in check running at 5v. And with the only other noise source a laptop HDD (and we all know how to make those quieter) this would be a very easy build even for the more timid noise haters.

Andy

Post by **MikeC** » Wed Oct 17, 2007 5:42 pm

andyb wrote: Apart from your comment about the PSU being noisy (21-22 Db is outragous )

right!

It's pretty quiet right out of the box... but as usual some people will want to get it quieter. I think the Tricool is the first limit, and then once you replace that with an undervolted Nexus / Scythe / etc ... then, it's the PSU. Which you can also try a fan swap with, like the Panaflo 80M mentioned above. Especially with a modest power system, it'll stay very quiet and fans will never change speed.

Kreed · Post by **Kreed** » Sun Nov 04, 2007 2:22 am

Ok, after much deliberation, I ended up going with the following setup:

- Abit AN-M2HD Motherboard
- AMD X2 4800+ (Brisbane Core, G1 Stepping)
- Antec NSK3480
- 1 Medium Speed Panaflo to replace the fan in the EarthWatt 380W PSU that comes with the NSK3480
- 1 Nexus 120mm Case Fan to replace the Antec Tricool that comes with the NSK3480
- Scythe Ninja Mini
- Arctic Silver 5 Thermal Compound

Some notes about the Abit AN-M2HD:
- It's a mATX board based on the Nvidia 7050/630A chipset.
- It's got 4 fan controllers: CPU, System, Auxiliary 1 and Auxiliary 2
- The CPU fan controller is a 4-pin PWM fan controller
- The System fan controller is a-3 pin fan controller
- The fan speed can only be adjusted using the CPU and System fan controllers
- The CPU fan controller is unable to control 3 pin fans
- CPU undervolting is not possible through the BIOS

The Ninja Mini wasn't easy to mount, but i eventually got there. My initial setup had the Ninja running without a fan. The Nexus 120mm was essentially the only fan running within the case.

Here are the results:

CPU Voltage: Stock (1.3 Volts)
CPU temperature at load (Orthos): System Shut down

CPU Voltage: 1.225 Volts (undervolted using CrystalCPUID)
CPU temperature at load (Orthos): Around 70-71 degrees Celcius

CPU Voltage: 1.1 Volts (undervolted using CrystalCPUID)
CPU temperature at load (Orthos): Around 55-56 degees Celcius

I had it configured so that when the temperature hit 55+ degrees Celcius, the Nexus fan will ramp up to 80% of it's full speed. When it's below 55 degrees, it runs at only 50%. What I found interesting was that the fan speed was around 1017 rpm at both 80% and 100%. As 50%, the fan was running around 550-600 rpm.

It would seem that the only way to run the Ninja Mini fanless is if I undervolt the CPU to 1.1 V. At this voltage, the 120mm Nexus Case fan ramps up to 1000+ rpm when under load. This is a bit loud for my liking. Also, I am not sure if having the CPU at 55 degrees is safe.

I then tried attaching the 80 mm fan that came with the Ninja Mini. Here are the results:

CPU Voltage: Stock (1.3 Volts)
CPU temperature at load (Orthos): 49-50 degrees Celcius

CPU Voltage: 1.1 Volts (undervolted using CrystalCPUID)
CPU temperature at load (Orthos): Can't quite remember, but I think it was around 40 degrees Celcius

So, with the fan attached to the Ninja Mini, the CPU temps are a lot better. However, the 3-pin 80 mm Scythe fan runs at 2000+ rpm, which is way too loud. Unfortunately, the CPU Fan controller on the Abit AN-M2HD is unable to control the speed of a 3-pin fan. As such, I am stuck with a noisy CPU fan.

I am now considering the following options:

1. Buy a QUIET 92 mm 4-pin PWM fan to replace the 80 mm Scythe Fan. A quick search through the forums haven't revealed winners here. Any suggestions people?

2. Buy a Nexus 92 mm fan and manually control it with a Fanmate. The disadvantage here is that I won't be able to control the speed of the fan through the BIOS or through Software.

3. Buy a Nexus 92 mm fan and connect it to the System Fan Controller (which is able to control 3-pin fans). Connect the Nexus 120 mm Case fan to one of the Auxiliary Fan Controllers (or the CPU Fan controller) and manually control it using a Fanmate.

At this stage, I am leaning towards option 3. With the Fan attached to the heatsink, I don't really see a reason for the 120mm case fan to run any faster than 700-800 rpm. I can control the speed using a Fanmate and let the Software worry about controlling the CPU fan speed.

What do you guys think?

FlorisNielssen · Post by **FlorisNielssen** » Sun Nov 04, 2007 3:24 am

Option 3.
The 92mm fan on the Ninja has more influence in the CPU-temp than the 120mm, so it is no more than logical to control the 92mm fan with software and let the 120mm run at a speed you like.

The CPU at 55 degrees is safe. Not low, but safe.

Undervolting is good by the way!

If your CPU is stable at 1.1V (if you test it for 12h+ with Orthos or Prime95 and you don't get any errors) I would surely keep it that way. Your cpu will run much cooler, your pc uses less power.

darkb · Post by **darkb** » Sun Nov 04, 2007 4:09 am

Just a quick note.. I had an Abit AN-M2 (same layout) a while ago, and my ninja rev.b fit it fine.
I don't recall having any clearance problems, and the fan control wasn't restricted by slow fan speeds iirc.

Also.. It has been a while, but i'm sure I was controlling both the scythe 120mm fan that came with the ninja and a 120mm nexus case fan using the motherboard.. was there a fan type option anywhere? with a newer bios rev. maybe? I'm not quite so sure now, i'll have another look next time i'm at my parent's house.

Kreed · Post by **Kreed** » Sun Nov 04, 2007 1:37 pm

darkb wrote: Also.. It has been a while, but i'm sure I was controlling both the scythe 120mm fan that came with the ninja and a 120mm nexus case fan using the motherboard.. was there a fan type option anywhere? with a newer bios rev. maybe? ....

I've got the latest BIOS (V16) and I can't seem to see any fan type options. As for using a full height Ninja, it's probably a bit late now, but definitely something to consider next time round.

Kreed · Post by **Kreed** » Tue Nov 06, 2007 4:45 am

A quick update. I decided to re-run the orthos test with the 80 mm Scythe fan attached to the Ninja Mini. The last time I ran this test with the CPU at stock voltage (1.3 Volts), I only ran it for 5-10 minutes. The resulting CPU temperature was around 50 degrees Celcius. This time round, I left it running for a longer period of time. After 1 hour, the CPU temperature was 57 degrees. Is this a little high considering the 80 mm Scythe fan is spinning at full speed (2000+ rpms)? Now I am starting to wonder if a 92 mm Nexus fan at 7V will provide sufficient cooling.

EndoSteel · Post by **EndoSteel** » Tue Nov 06, 2007 9:29 am

Kreed wrote:After 1 hour, the CPU temperature was 57 degrees. Is this a little high considering the 80 mm Scythe fan is spinning at full speed (2000+ rpms)?

Diagnosis: thermophobia

.

Post by **MikeC** » Tue Nov 06, 2007 10:15 am

EndoSteel wrote:
Kreed wrote:After 1 hour, the CPU temperature was 57 degrees. Is this a little high considering the 80 mm Scythe fan is spinning at full speed (2000+ rpms)?
Diagnosis: thermophobia .

Somewhat.

Just ask yourself how often you're going to put that kind of load for an hour on your system? Other than running CPU torture/benchmark tests, I never push my systems like that. In actual use, my <22dBA/1m system w/ 5/7V fans hardly ever reaches >50C on the CPU even when weather is hot.

Firetech · Post by **Firetech** » Tue Nov 06, 2007 10:04 pm

Kreed wrote:I've got the latest BIOS (V16) and I can't seem to see any fan type options. As for using a full height Ninja, it's probably a bit late now, but definitely something to consider next time round.

The manual (section 2.8 PC Health options) says there is CPU & System fan 'FanEQ' controls + 2 aux fan monitors. Is that not the case?

Kreed · Post by **Kreed** » Thu Nov 08, 2007 3:03 am

Firetech wrote:
Kreed wrote:I've got the latest BIOS (V16) and I can't seem to see any fan type options. As for using a full height Ninja, it's probably a bit late now, but definitely something to consider next time round.
The manual (section 2.8 PC Health options) says there is CPU & System fan 'FanEQ' controls + 2 aux fan monitors. Is that not the case?

FanEQ options allow you to choose the temperature at which you want the fan to spin at a particular speed.

e.g. you can set it so that the fan will spin at 80% of it's full speed when the temperature reaches 55 degrees (50 + 5 degree tolerance).

It doesn't let you choose between PWM or DC type fans. In the same section, if you look at page 2-17, it also says:

"The 3-pin fan assembly connected at this 4-pin "CPUFAN1" fan power connector will have no speed control function"

Further down it says:

"In the situation when connecting a 3-pin CPU fan assembly, and you still want the speed control function to take effect, you must:
1. Plug the 3-pin CPU fan assembly to "SYSFAN1" fan power connector.
2. Set the "SYS FanEQ Reference Temp." item from the default "System" to "CPU".

Felger Carbon · Post by **Felger Carbon** » Thu Nov 08, 2007 7:24 am

Kreed's posting above is correct. Here's how the mobo controls the fan speed:

On the 4-pin CPU mobo fan header, pin 2 is hard-wired to +12V. Pin 4 is a PWM control signal for a 4-wire PWM fan. It has no effect on fans with 3-pin wiring, obviously.

On the 3-pin Sys mobo fan header, pin 2 is a "power PWM" connection - at any given instant, it's either connected to +12V, or an open circuit (no power). This signal alternates ~25,000 times per second (~25KHz), so you should not be able to hear the alternations.

(Years ago, some 3-pin fan controllers were sold that used a much lower PWM frequency. Alas, these fan controllers are still on the market. They sound horrible - I know, I bought 2 of them {the Logisys model IIRC} about 30 months ago.)

Kreed · Post by **Kreed** » Mon Nov 12, 2007 8:56 pm

Another update.

I have attached a 92mm Nexus Fan to the Ninja Mini. Without CPU undervolting or Cool'n'Quiet enabled, the load temperature hovers around 70 degrees celcius when the fan is spinning at ~ 1000 rpm after 30 minutes.

In normal use, I have CnQ enabled and the fan spinning around 400-500 rpm. Temperature is around 38-40 degrees celcius.

With CnQ enabled, I am reasonably happy with the set up: 120mm Nexus Case fan running at around 700 rpm and 92 mm Nexus fan running at around 400-500 rpm. It's near silent at 1 m. At 30 cm, I can hear it, but it's not bothersome like my old Shuttle.

In hindsight, the Full Height Ninja would probably have been a better choice.

Firetech · Post by **Firetech** » Mon Nov 12, 2007 9:27 pm

Kreed wrote:In hindsight, the Full Height Ninja would probably have been a better choice.

If you were in Sydney, I'd do you a swap

Kreed · Post by **Kreed** » Mon Nov 12, 2007 9:51 pm

Thanks for the offer mate, but I live in the City of Churches. After cutting my fingers several times trying to mount the darn thing, I am not keen on unmounting it. I have also applied the thermal compound and it may get messy removing it.

djkest · Post by **djkest** » Tue Nov 13, 2007 8:50 pm

Mini ninja really really torqued my motherboard when I installed it. It's scary. At least I know it's on there with a lot of pressure.

Currently being cooled by 2 noctua fans @800 rpm about 3cm away.