Serenity i7 Sandy Bridge PC, SPCR Edition, by Puget Computers

Time flies in the tech world. Blink, turn your head for a moment, and today’s greatest technology is yesterday’s news. So it is with the Serenity PC, SPCR Edition. The previous edition turned out to be the quietest computer system we have ever reviewed or even laid our hands on, and probably quieter than any PC will ever be, short of one with no moving parts and zero electronic noise. Another 3.5 months later, the latest SPCR Edition of the Puget Serenity with Sandy Bridge is here.

Time flies in the tech world. Blink, turn your head for a moment, and today’s greatest devices, gadgets and technology are yesterday’s news. So it is with the Serenity PC, SPCR Edition. Less than four months after its initial June 2010 release, this model was updated with better, quietest components. The second edition turned out to be the quietest computer system we have ever reviewed or even laid our hands on, and probably quieter than any PC will ever be, short of one with no moving parts and zero electronic noise. Another 3.5 months later: The Intel Sandy Bridge processors and socket 1155 boards are here. So is the latest SPCR Edition of the Puget Serenity.

The table below details
the changes and commonalities among the three versions of Puget Serenity i7, SPCR Edition. It is color coded, as per the key below.

The fundamentals are the same, and there are only two real hardware changes from V.2: The processor and the motherboard. Puget has stuck with an ASUS board; the P8P67 Pro could be regarded as the socket 1155 version of the 1156 board used in the previous version.

Here are some notes from Puget about v.3:

A. The 160GB Intel SSD is no longer a very competitive SKU. We now recommend the 120GB version. While 40GB smaller, it is also $212.83 less. (120GB is still plenty for an OS/programs drive for most users, and there is no difference in performance.)

B. We’re also back to the 850W PSU for the Serenity. It is only $30 cheaper, so it isn’t about price. 1000W was just overkill. (850W is still overkill for this system, which does not even hit 25% of the PSU’s rated power. But it is the lowest rated PSU Antec offers in the P183-perfect CP series.)

C. RAM is 2x4GB now. 4GB DIMMS have come down in price quite a bit, so they are now our default

D. The test system price is $230 lower than the v.2 sample. (And it’s a better performer in every way!)

Here is a note from Puget about the changes from v.1 to v.2, which remain unchanged for v.3:

1) We’ve now made a custom plastic plate for blocking the top vent.
It’s just more polished, but also blocks the sound a tad bit better. We had
to make a ton of them to make them economical, so we
sell them now too!

2) We’ve updated all chassis fans to Scythe Slipstream 800rpm, at 5V.
We did a LOT of testing, and we’re very happy with the temperatures, and are
confident that we’re not going to find much quieter than this! Temperature
logs are provided in the packet with the PC we’re sending you, though I’m sure
you’ll be testing yourself.

3) We’ve updated the CPU fan to Scythe Slipstream PWM. We have gone
through the BIOS, and instead of relying on the default "Silent"
QFAN profile, we have custom tuned the fan ramping curve to provide the lowest
noise levels while maintaining good temperatures. We also tuned it to prevent
cyclic patterns of the fan ramping up and down. We keep it nice and smooth,
and in fact, our full load speed is only 30% higher than our idle speed. We
have this VERY well dialed in.

4) For the SPCR edition, we
are now cherry picking components from our shelf that are the quietest. We’ve
found that even with the same model of component, there are variations in
noise level. Hard drive spindle noise, power supply fan noise, motherboard
electrical noise (we’re so quiet now that that’s one of the loudest items!)…
we set aside the quietest components for SPCR packages. We’re branding this
"Picked by ear." (Editor’s note: This could be as significant
as the change in fans!)

5) We’ve done some minor power management tuning in Windows 7. None
of it is necessary to ensure quiet operation or good temperatures. We wanted
to make sure customers get the same experience even if they reinstall the
OS. Mainly, we’re just decreasing the inactivity time before the secondary
drive spins down.

Everything else about the system is the same as in the original Serenity, so
there’s no point going over those details again. Please refer to the
original Serenity review for details on the great packaging, documentation,
external cosmetics, etc.

Serenity
PC page at Puget Custom Computers
The SPCR-certified Silent
PC Program
Serenity i7 PC, v.2


Original Puget Serenity SPCR Edition
Review

The interior of this system is little changed from the previous versions, with AcoustiPack
acoustic damping on the interior panels, and meticulously neat cable management throughout.

This interior photo is from the original, but it is visibly very similar to v.3. AcoustiPack acoustic damping lines both side covers, the top panel, and the front door. The damping is cut and fitted so that the side panel will close properly against the tight-fitting divider between the upper and lower sections of the case. This view shows the cooling systems perfectly: In the PSU chamber, the in-line 120mm fan of the CP-850 power supply cools itself and provides a steady cooling flow of air across the hard drive and SSD. Directly above, the 120mm intake fan blows air from the front across both sides of the video card, with the hot air exhausting partly through the ventilated PCI slot covers. Up on top, the CPU heatsink fan and case exhaust fan are lined up almost perfectly, providing push-pull airflow for the heatsink, while ensuring airflow for other components on the motherboard. The airflow originates from vents on the front panel. All three case fans are Scythe Slipstreams. Here’s a good view of the intake fan for the top chamber, the Gelid Tranquilo heatsink/fan, and the passively cooled HD5750 video card. Note the thin zapstrap across the Scythe Slipstream intake fan for extra security.

Serenity
PC page at Puget Custom Computers
The SPCR-certified Silent
PC Program
Serenity i7 PC, v.2

Original Puget Serenity SPCR Edition
Review

ACOUSTIC & THERMAL CHARACTERISTICS

This is the core of the SPCR certification for a PC. Many tools were used to
analyze the system:

• Prime
  95 (CPU & memory stress test)
• Speedfan
  (hardware monitoring)
• Throttle
  Watch (monitor CPU throttling due to overheating)
• CPUID Reviewer Kit for Intel Sandy Bridge

  • CPU-Z 1.56.1

  • HWMonitor 1.17.1

  • TMonitor 1.03.1

  • AIDA64 Extreme Edition 1.50.1200
• GPU-Z to monitor the GPU.
• FurMark
  stability test to stress the integrated GPU.
• Seasonic
  Power Angel AC power meter, used to measure the power consumption
  of the system.
• SPCR anechoic
  chamber and lab
  reference quality sound measurement / recording system.

The basic approach is to assess the noise, thermal and power characteristics
at idle, and then at full CPU and GPU loads. The testing was conducted entirely
in the SPCR anechoic chamber, with the door open to ensure adequate room ventilation
when noise measurements or recordings were not being performed. Measurements
under load were recorded 60 minutes after the tests were started. This is an
artificially long time for both CPU and GPU to be at full 100% load; it would
hardly ever happen in actual use with real applications.

1. Noise

The Puget Serenity i7 Sandy Bridge SPCR Edition is just as silent as v.2. The
measured sound pressure level of 11 dBA@1m at idle and not quite 13 dBA at
full system load is the same as v.2, and it is at the same level as any fanless PC with a single,
natively-quiet, super-well muffled hard drive. The v.2 and 3 systems are quieter at full
load than the original system was at idle. That’s pretty impressive, especially
as the original was extremely quiet.

At idle, it is still really hard to tell that the system is on using only sonic
cues, even sitting next to it (with the system on the floor as it should be).
Compared to any other fan-equipped PC we’ve encountered
or even assembled ourselves, this one is quieter.

The ISO 7779 computer noise standard’s defined "Seated User Position"
SPL places the microphone about 0.6m away from the top/front of the PC, which
explains the 2 dBA higher readings. This is an unrealistically close distance
for a PC in a case as large as the Antec P183, which is designed for placement
on the floor; few users would put it on top of the desk.

The frequency spectrum of the Serenity i3 Sandy Bridge SPCR Edition shows small rises above the ambient noise floor of the anechoic chamber, mostly below 600Hz. At idle, it is essentially identical to the ambient of the chamber, which is about 10.5 dBA. The original Serenity showed a bit of a tonal peak at ~90Hz, at the fundamental frequency of the WD Green hard drive, and another around 200Hz. The v.2 and v.3 systems are quieter at full load than the original system was at idle. .

Audio Recordings of this system were not made. There is no point.
It is virtually silent in the anechoic chamber and it will be silent in almost
any environment.

2. Cooling

The various components stayed well under maximum safe limits through the
CPU load testing, but they ran significantly hotter when both CPU and GPU
were fully loaded. The maximum speed of the CPU fan dropped from 1030rpm in
the previous version to 880rpm in the current configuration. They are different
fans, and do not necessarily have the same airflow at the same speed, but
it’s clear the new fan at 880rpm does not move as much air as the previous
one at 1030rpm. In any case, despite higher overall temperatures, the components
temperatures remained safely below maximum limits.

Puget expressly states that this PC is designed for quiet operation in an
ambient of up to 30°C. This is a fair statement under normal use conditions.
Under such conditions, the CPU fan will probably still not rise much beyond
880rpm, as it Puget has custom-set the fan controller in the BIOS.

3. Power

The idle state AC power consumption of 68W is modest for a power ful system and slighly lower than the previous version.
The maximum CPU/GPU load
power of 215W AC is a big drop from the 263W of the previous version. The similar drop in Prime95 load indicates that the improvement in power consumption can be attributed to the new CPU (and P67 motherboard). Another significant improvement is the 0.3W AC power seen when the system is powered off or in sleep mode. Even a rabid eco-green user will not feel compelled to power down and switch off the power bar.

4. Performance

No conventional performance benchmarks were run on the system. The performance of the Intel i3-2600k is already well documented in the tech press; it is superior in almost every benchmark than the previous v.2’s Intel i7-875 CPU. The graphics capability
of the ATI HD5750 is also well known. There were no problem
of any kind encountered during our testing. Windows 7 Home Premium 64-bit
provides a mature, smoothly operating environment. The quick boot time of under 35 seconds (from power
button press to actual usability at the desktop) remained unchanged.

CONCLUSIONS

The Puget Serenity i7 Sandy Bridge SPCR Edition extends the tradition established by the previous iterations of this PC. It is superbly assembled, provides better performance and draws less power than its predecessors, and remains extremely quiet in our test conditions. In fact, it is hard to imagine any setting where the system’s noise would be audible in normal use. The ambient noise floor in any common human habitation is louder by many decibels. The system remains unique in the use of components cherry picked (or binned, to use an well-known industry
term) for lowest noise. This unique selection service, the carefully chosen fans, the performance and energy efficiency improvements of Sandy Bridge all combine to
make our third Serenity PC test sample not only the quietest fan-equipped PC we’ve ever tested
but the most capable. It bears comparison even with PCs that have
no moving parts; some of them will actually have more electronic noise (high
pitched, sometimes intermittent whine) than the Serenity. Puget’s SPCR-certified
Serenity PC is a truly well-crafted high performance computer that remains at the cutting
edge of silent computing.

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Serenity
PC page at Puget Custom Computers
The SPCR-certified Silent
PC Program
Serenity i7 PC, v.2


Original Puget Serenity SPCR Edition
Review

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