 As
7200rpm hard drives are the standard today, and high-rpm drives are
found in most desktop PCs, and not just in servers, hard drive cooling
has become a more important issue.
Most recent IDE hard drives come with
internal temperature sensors, and are capable of reporting their
operating temperature via SMART; software utilities are available for
displaying the temperature of your hard drive. This temperature readout
is not very precise, but definitely good enough to give you a hint
whether your drive is running too hot or not. Consult the website of
your hard drive manufacturer to learn about the maximum operating
temperature of your hard drive. Typical maximum temperature range is
50-55°C, with some drives being able to operate at up to 60°C.
There is, however, an important factor to
consider:
Unlike CPUs, which are reliable parts, and fail rarely (even when
operated very close to their maximum temperature), hard drives tend to
fail more often than any other part in the PC. The MTBF (mean time
between failure) of a hard drive can be substantially increased by
lowering the drive's temperature. Some drive manufacturers even state
this fact in their drives data sheets; but even if this information
isn't included there, it is still true. So, even if your drive never
exceeds its maximum allowed operating temperature, additional cooling
will improve the drive's reliability.
Does hard drive cooling affect
performance?
Although this is often claimed by
manufacturers of HDD cooling products, the temperature does not directly
affect the performance of the drive in any significant way - seek times
and data transfer rate will stay the same, no matter how hot the drive
is running.
Old hard drives had a thermal
recalibration loop - from time to time, the hard drive would make a
short pause and recalibrate itself. When the drive warmed up, the
platters expand, and their geometry changes, thus making recalibration
necessary. With such drives, good cooling resulted in less frequent
recalibration, and therefore did improve performance, especially for
Audio/Video applications. However, these days are long over - all recent
drives with embedded servo do not have a thermal recalibration loop.
Temperature will not affect performance in any way.
Do drives only get hot when accessed
often?
No. What generates most heat in a drive is
the friction between the platters and the air that surrounds them. The
magnetic plates inside the drive rotate at a high speed, but the air
inside the drive doesn't, and even if the plate is perfectly flat,
there's a lot of air resistance, so a powerful spindle motor is required
to keep the drive spinning at high speed.
The movement of the drive's heads and the
heat emitted by the drive's electronics only have a small contribution
to the total heat emitted by the drive. Therefore, even drives that are
mostly idle still require cooling (unless, of course, auto-spindown is
enabled and the drive shuts itself down after not being accessed at all
for a longer period of time).
Hard drive cooling solutions
The best solution for cooling hard drive is
one that is well-integrated with the case cooling concept. When
purchasing a case, make sure that fan intakes and drive bays are located
in a way that proper cooling of the drives is possible. A fan bay for a
large fan (the bigger, the better - server cases usually come with 120mm
fan bays) right in front of the drive bays is perfect. If your case has
a fan bay suitable for cooling drives, get a good fan and install it
there. This is cheaper than buying a dedicated hard drive cooler,
provides good cooling for the drive, and will have a positive effect on
overall case ventilation.
Dedicated hard drive coolers
If your case does not allow proper
ventilation of the drives by using normal case fans, you might want to
look at special hard drive coolers. A multitude of different models are
available on the market; they usually come with small 40mm fans, which
are less efficient and typically louder than larger case fans. Some come
with heatsinks for hard drive cooling, others rely on fans alone.
There are, however, exceptions to this
rule, like the Global WIN IStorm, which features an unusual cross-flow
fan.
The most simple hard drive cooler simply
consists of a 5.25 drive bay cover with two embedded 50mm fans.
More advanced drive coolers come with a
heatsink/fan combination, or are just large passive heatsinks that
should be mounted on the drive (which, of course, only helps if there is
at least a minimum amount of air flow across the drive).
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