***Bottom-Line***: If you are looking for a robust (expandable) 5U rack mount (or tower) server with plenty of storage potential, the **HP Compaq ML370 (G4)** might very well fit the bill. The **HP Compaq ML370 (G4)** continues Hewlett Packard/Compaq's long tradition of building quality enterprise-class server platforms. HP builds the **HP Compaq ML370 **in several different configurations; 3U and 5U chassis designs. The 5U chassis design incorporates an *HP StorageWorks DAT-72* Tape Backup Unit (TBU) into the design, while the base unit looks very similar to the *Dell PowerEdge 2800* series 3U rack servers. We currently have two 5U **HP Compaq ML370's **installed. The server can also be bought as a standard tower design. The 5U rack-mount **ML370** chassis design moves the six-disk hot-swap cage to the far left hand side of the box and stacks them on top of one another, leaving room in the center of the box for up a DAT-72 TBU, 5.25 inch CD-ROM/DVD-ROM, and more hard drives if needed. Altogether there are three external 5.25 inch bays. One the far right of the chassis behind a hinged door you will find the power and resent switch, several LED indicator lights and the USB ports, as well as an integrated 3.5 inch floppy drive. All of the Ultra320 SCSI drives come mounted in industrial-strength metal carriers, and the maximum (native) storage is 1.8TB utilizing 6x300GB Ultra320 15,000rpm drives. Access to the inside of the **ML370** is easy to access via a quick release panel. The internal design of the **ML370** is neat, efficient, and orderly; all pertinent interfaces are mounted on the leading edge of the motherboard right next to the devices they are serving, cutting down on the length of the cables. The Intel 64-bit Xeon processors, which can be swiftly removed via a large easy-to-use clamp on the side-are located behind the hard disk bay and covered by a plastic conduit to help direct airflow and promote cooling. And of course each processor is covered by a very large, but needed passive heat-sink. The power distribution board is mounted under the main board, a design I have never seen before, but it saves valuable space inside the chassis. The base **ML370 **ships with a single hot-swappable 775W power supply which is of coursed accessed at the rear of the chassis, but for fault tolerance a second power supply can be added. Internal cooling is handled by three hot-swappable low noise fans mounted in the center of the chassis. Room for a fourth hot-swappable cooling fan is provided for in the right hand bay if needed. To the left of the processors is a bank of eight DDR2 DIMM sockets; The **ML370** was one of the first enterprise-class servers to ship with the new PC2 memory configuration. The **ML370 **ships with a pair of DDR2-400 (400MHz) 512MB SDRAM memory modules in a dual channel configuration. DDR2 memory modules in addition to being noticeably smaller than DDR modules also use lower voltages (1.8 volts vs. 2.5 volts for DDR) and higher clock speeds, which allow for faster throughput. Lower voltages also translate into less heat. DDR2 memory utilizes FBGA (fine ball grid array) packaging that allows chip density to be significantly increased. Currently, HP can ships 256MB, 512MB, 1GB, 2GB, and 4GB modules. There is a lot of room for expansion within the chassis of the **ML370**. HP equipped the box with (4) 100MHz/64-bit PCI slots as well as (2) 4X PCI-Express slots. The **ML370** is also equipped with an integrated HP NC7782 Dual Port PCI-X 10/100/1000T Gigabit network adapter. Dual Ethernet adapter are expected in enterprise-class servers, and one has to look critically at one that does not ship with a dual adapter. The back of the **ML370 **is dominated by two removable cooling fans on the right and center of the chassis. To the left of these you will find the (6) PCI expansion slots. Two bays for the two hot-swappable power supplies are located near the bottom of the chassis further underscoring the placement of the power distribution board under the main system board. Immediately above the power supplies and set off to the left are the port for keyboard, mouse, video, Ethernet, as well as the remaining USB ports. **My Viewpoint ** So what does the **ML370** do for our business? It runs a legacy (non-Microsoft) application for one of our specialty departments. Along with its mate the **ML370** is pretty much stand alone; connected to our environment but not interacting with it in any significant way. Since the server is running a database we installed 146GB Ultra320 hard drives in each bay with one hot-swappable spare giving the **ML370** 730GB of storage space. The business opted for two processors, 4GB of RAM in for banks, and two power supplies. And as I stated earlier we had an *HP StorageWorks DAT-72 *TBU factory installed in one of the three available 5.25 inch drive bays. The DAT-72 TBU is used to perform nightly backups of the database. Another drive bay is taken up by a 24x CD-ROM drive. The remaining drive bay remains empty but could be optionally filled with two further Ultra320 hard drives. Word to the wise: this server is heavy-even without the hard drive installed-so I would mount the chassis barebones and use two men unless you want permanent back problems. The racks themselves are hardy and easy to install, and allow ready access to the server. Since being brought on-line some 1.5 years ago, the server has never suffered a failure of any kind, which speaks volumes of the reliability of HP Compaq servers. And it is worth noting that the server is on-line 24/7/365 with very little scheduled down-time for maintenance. **Conclusion** Though most of our NOC is equipped with Dell servers of various makes and models, our complement of **HP Compaq ML370 (G4)** servers are in no way considered inferior; they very much hold their own against their black and gray competitors. And they suffer from far less down-time. If you are looking for a robust (expandable) 5U rack mount server with plenty of storage potential, the **HP Compaq ML370 (G4)** might very well fit the bill.