Arctic Cooling Silentium T2

Cases|Damping
Viewing page 7 of 7 pages. Previous 1 2 3 4 5 6 7

HEATSINK SWAP

Because the airflow over the CPU area of the motherboard was so effective at cooling our test heatsink, we decided to do a further test to see if we could run a CPU without a direct mounted fan by relying on the case airflow to cool the heatsink. Our heatsink of choice: An Arctic Cooling Freezer 4 with the stock fan removed.


Arctic Cooling Freezer 4: Four tiny screws were undone to remove the fan.


Here it is, fanless and installed. More about that piece of cardboard later...

Arctic Cooling Silentium T2 w/ Fanless Freezer 4
CPU Conditions
CPU (°C)
SS4UTC*
CPU (°C)
Case (°C)
HDD (°C)
SPL
(dBA @1m)
Idle
33
33
30
29
27
Folding@Home
47
52
33
33
31
CPUBurn
51
57
32
32
32
*Performance with first HSF: Arctic Cooling Super Silencer 5 Ultra TC

Idle: At idle, the fanless Freezer appears to cool very similarly to the Super Silent 4. The noise level did not drop appreciably despite the absence of the fan because the SS4UTC's temp controlled fan made so little noise, especially in the context of other noise sources in the case.

Burn: The true test of a heatsink is not how it performs under idle conditions, but how it withstands the stress of a CPU benchmark. After 20 minutes of CPUBurn, the CPU core reached 57 °C, 6°C higher than with the fan-cooled SS4UTC, but well within the safe thermal limit for our chip. For a heatsink to perform this well fanlessly is quite impressive, though this is also a testament to the airflow within this case.

Eliminating the fan of the first heatsink, the AC SS4UTC, as a noise source dropped the measured noise level by ~2 dBA/1m at full load. Subjectively, this drop in noise is minor, mostly wind turbulence and low frequency rumble; the main source of noise is still the hum produced by the power supply fans.

AIRFLOW EXPERIMENTS

Because the exhaust fans are located right next to the intake vents, we speculated whether some of the intake air might be getting exhausted immediately without cooling the case. To find out, we installed a cardboard ledge in the space usually occupied by the bottom of the power supply in order to route the air further into the case before it is exhausted. We'll call it an airflow guide (in the best marketingspeak tradition).


Does having an intake so close to the exhaust fans make sense?


To find out, we blocked airflow between the intake and the exhaust, forcing the air to travel across the heatsink before it leaves the case.


The airflow guide installed in the case.

The airflow guide appeared to have no effect on our first heatsink (the fanned AC SS4UTC); there was no measurable difference either in idle or under load. This means that the airflow in the case is already adequate for the heatsink without the guide.

Because our second heatsink, the AC Freezer 4, was run fanless, we guessed that the airflow guide might have more of an effect. At idle, we were disappointed again; there was no measurable change in temperatures. The only time our airflow guide made a measurable difference in temperatures was with the fanless Freezer 4 cooling the CPU at full load. After 20 minutes of CPUBurn, the temp was 2 °C lower with the guide than without it. Strangely, the hard drive temperature also dropped a degree, but this is probably not a statistically significant change.

Unless you're rabidly obsessive about getting the absolute lowest CPU temperature under all possible conditions, the airflow guide is probably an unnecessary mod. Its effect was negligible under all but the most stressful conditions. Such an airflow guide might be more useful with a much hotter CPU like a >3.2 GHz Prescott. In any case, Arctic Cooling has done a good job of engineering the airflow paths in this case.

CONCLUSIONS

The Silentium T2 was quite an interesting product to review. Its advantages and nuances are not immediately obvious from a cursory glance. Unfortunately, its main disadvantage is obvious as soon as the power supply is turned on; the power supply fans are significantly louder than the exhaust fan, despite both pairs of fans being identical models.

Case airflow is exceptional. The main airflow path is directly from the outside to the CPU and VGA, or across the motherboard and HDD. The CPU and VGA card are cooled by air that is at room temperature, not case temperature. This case could probably support a much higher-powered system than our test system, although for it to remain reasonably quiet, the system would be limited practically to just one hard drive -- the suspended one.

The hard drive suspension system works as claimed, and the HDD was never a significant source of noise. As a bonus, the HDD Muffler also cools the hard drive very effectively. However, the plastic cap that fits over the end is hard to remove, and breaks easily. Aside from that flimsy cap, this is a very good commercial implementation of what many PC silencers have been doing for years.

There are some minor issues that make the case unpleasant to work with.

  • All the plastic in the case is brittle, meaning that it breaks easily.
  • The front panel cables could have been an inch or two longer.
  • The right panel is not removable, and the left panel requires the base to be removed before it can be opened.
  • The base / case interface is really awkward and could use rethinking.

Most of these are installation issues, that, hopefully, only need to be dealt with infrequently.

The main difficulty that we have with this case is, of course, the noise the PSU fans produce, especially as the load is increased. We know the PSU fans are louder because they run faster than the back case exhaust fans. There may also be some extra resonance caused by vibrations going from the fans into the PSU and chassis as well. We also know that these fans can be much quieter, judging by the identical fans that are running slower on the back panel.

We contemplated removing the PSU to either swap the fans or slow them down with extra resistance or diodes in the voltage feed to them, but decided against it. It's something only a small portion of even the hardcore SPCR audience would undertake. The power supply is really quite integrated into the case, and not designed to be removed. So most users will be stuck with the stock fans in the PSU as they are.

Admittedly, the >20 minutes of CPUBurn's intense CPU loading is hardly the kind of thing a normal PC user will do. It is a worst case scenario for noise. In more typical desktop usage, the system built in the case stayed close to the idle level of 27 dBA/1m, and the PSU fans rarely ramped up the way they did under CPU stress testing. In normal use, it is a pretty quiet system.

But still, with the relatively high efficiency of the Seasonic PSU and the high airflow afforded by the open design of the airflow path through the PSU, you would think those dual PSU 80mm fans could afford to be run slower than they are. We think the engineers went too far in playing it safe for cooling. If adequate cooling for hot climates and conditions was an issue, they could simple have put in a lockable user-selectable fan speed switch. One that keeps the thermal control in place but simple lowers and raises the sensitivity. A minor drop in the speed of the PSU fans could make a dramatic improvement.

Despite excellent airflow and cooling superior to running the system on an open test bench, our ultimate verdict of the Silentium T2 is that it allows for a system that is quiet, but probably still not quiet enough for those who are seeking "silence". It is also not easily made quieter. It may be a good option for system integrators who want to produce inexpensive noise reduced systems. Perhaps a second generation version will prove more satisfactory for more demanding silent PC enthusiasts. We certainly applaud Arctic Cooling for the creativity and innovation shown in this adaptation of the ATX standard; more efforts like this will ensure an extended life for ATX.

PRO

Excellent airflow / cooling
Pretty quiet in normal use
Good one package deal
Nice compact size
Sturdy steel chassis
Decent styling
Very effective HDD Muffler
Very good quality PSU
CON

PSU fans get loud under load
Cheap plastic
No filters!
HDD installation a bit clumsy
Poor base / chassis integration
Short front panel cables

Many thanks to Arctic Cooling for the Silentium T2 sample.

POSTSCRIPT Feb 2, 2005: MORE THOUGHTS, SOME REVISIONS

It's normal for writers to go over their work after it has been published. Devon and I did just that, and we discussed the issue of how much the placement of the Silentium T2 on the somewhat resonant table top affected our perception of its noise. This required another setup and another round of listening along with a few more SPL measurements.

Placed on the floor, the overall noise IS reduced by about 3 dBA at full load. This brings the SPL down to about 29 dBA/1m at full load with the fanless Freezer 4 heatsink -- but it does not change the basic character of the sound, the broad humming in the mid-band that annoyed both of us. However, in normal use and at idle, the overall level dropped down to about 24~25 dBA/1m.

The reduced volume of noise in normal use persuaded us to soften our overall verdict of this case; web publishing gives us this privilege:

The Silentium T2 is a good case for someone seeking a simple base for a quiet computer. In this regard, it can be compared to the similarly priced but far more conventional Antec Sonata case, which has been wildy successful by offering a noise-reduced package that allows for quieter than typical systems. In fact, for airflow management, component cooling, HDD silencing and the quality of the PSU supplied, the Artic Cooling Silentium clearly beats the Sonata. That comparison helps put this product into better perspective: There are many PC users who would find the system we assembled in this case perfectly quiet. Given the modest price, the cooling and acoustic performance offered is quite good, and the range of innovations offered is impressive.

* * *

Discuss this article in the SPCR Forums.



Previous 1 2 3 4 5 6 7

Cases|Damping - Article Index
Help support this site, buy the Arctic Cooling Silentium T2 from one of our affiliate retailers!