The nodes sport six SATA interfaces and base RAID options start with the embedded Smart Array B110i controller which supports cold-swap mirrors and stripes for SATA drives. You can use the node's PCI-e slot to add a Smart Array P212 PCI-e card which supports SAS and SATA drives, battery backed-up cache and RAID-6 arrays. There's also the P410i card, which has internal SAS ports, and supports HP's new Flash backed write cache.
All cooling is handled by a row of four fans behind the disk backplane but these are not hot-swappable. It's here that bad design and cable clutter really get in the way as replacing a failed fan requires the upper node behind it to be completely removed along with the power supply cage.
Power options are plentiful as the chassis supports a pair of hot-plug supplies and uses HP's common power slot bays which reduce costs as all new ProLiant servers use the same modules. We were provided with a single 1200W supply but HP also offers 460W and 750W models.
The DL4x170h is very easy on the supply recording a 28W draw in standby. We then powered each node up and took measurements with them running in idle and with SiSoft Sandra pushing all cores on each one to near maximum utilisation.
