One of the best known and respected manufacturers of enterprise grade storage hard drive is Seagate. They not only helped create this marketplace but have kept their prominent position via timely new releases which set the standard, routinely outpacing their competitors.. The latest addition to Seagate’s enterprise storage division is a series of seemingly benign 7200 RPM drives dubbed the Constellation ES.3 series which are available in capacities up to the 4TB SAS version we’re reviewing today. Also take note that Seagate has recently simplified their nomenclature, leading to this drive being called the "Enterprise Capacity 3.5 HDD V.3".The ES.3 series’ goals aren’t solely focused upon performance but rather they’re designed to deliver a combination of elements specifically targeted towards the enterprise market. Longevity, efficiency and data retention capabilities have all been fine tuned in an effort to outstrip the offerings from the likes of Hitachi, Western Digital and others. Remember, efficiency may not matter when one, two or three drives are being used in parallel but when running arrays of several dozen HDDs, power savings really begin to pile up.A new Constellation drive may not sound as impressive as Seagate’s blazingly fast 10K Savio or 15K Cheetah products but for many scenarios, its 7200 RPM speed is sufficient and actually optimal for its intended use. This class of drive runs cooler, consums less energy, can incorporate higher density platters for greater capacity and generally boasts a lower Total Cost of Ownership than their 10K and 15K counterparts. All of this is exactly what the new Constellation ES.3 has been designed to do: be the most efficient and effective storage tool available today for enterprise customers.Like most drives in this class, the ES.3 line comes into a multitude of models with everything from SATA, to SAS, to self-encrypting AES 256 (FIPS 140-2 level 2 compliant) models. Today we will be testing the mid-tier Serial Attached SCSI models which have no encryption abilities. We have chosen this model as SAS drives are the ‘Honda Civics’ of the business world. Put another way, the ES.3 SAS version is as ubiquitous in this segment as it is capable.From the exterior, consumers would have a tough time distinguishing this SAS version from the SATA equipped model. Both SATA and SAS ES.3 Constellation’s come in a standard 3.5” form factor and make use of the same color scheme. The only way anyone could reliably tell any of the ES.3’s apart is by reading the label on the top or taking a very close look at the ports.SAS was created to be more user friendly version of SCSI and SAS data ports uses the same design as SATA but with a few minor tweaks. Basically, SAS cables can be used with SATA drives, but SATAare unable to connect to and use SAS drives. Unfortunately, since Intel removed the rumoured SAS abilities from their newest PCH, this does mean that a dedicated SAS controller will be required for testing. To this end we have opted for an entry level LSI 9240 controller, but will be using it only for connectivity. All RAID work will be carried out via Microsoft Windows 7’s built in ‘software’ RAID abilities.The SAS ES.3 may be similar in appearance to most drives we have looked at to date, but once the PCB is removed some obvious differences do become apparent. Like any modern high performance HDD, the ES.3 4TB makes use of a Marvell-based dual core controller and exterior ram cache. Like all enterprise drives there is also humidity, accelerometer and pressure sensors attached to the PCB. This too is par for the course and very similar to Western Digital’s RE-series layout.Unlike Western Digital’s offerings this new model makes use of 128MB of cache instead of the industry standard 64MB. In most instances renewal of the old ‘cache wars’ would not be noteworthy, but these drives are meant for RAID environments and deeper queue depth scenarios. In such scenarios the added onboard cache is welcome and may indeed help the ES.3 out muscle the competition.