For those not familiar, the K series is used for the Zen XPC, which is about 20% smaller than the usual G series. By contrast, the P series is about 20% larger than the G series, and it includes many of the provisions we've been asking for in our reviews of SFF systems.
The P series includes a matrix LED display, and it also has room for a pair of external drives, with both bays concealed by spring-loaded covers.
The top 5.25" slot has a unique eject button, placed in the top right corner of the front panel, that doesn't slide out with the tray, so it can be used to tell the DVD drive to pull the tray back in, as well.
The first P-series product will be the SB81P, a Pentium 4 system based on the Intel 915 Express chipset with PCI Express, four ports of Sertial ATA RAID, and an LGA775 processor socket. The P series chassis has room for two 3.5" internal hard drives, making SATA RAID in an XPC possible.
Shuttle has designed the P-series motherboard and chassis around the BTX spec, but has bent the rules a little bit to make things fit. For instance, rather than use front-to-back cooling, the SB81P uses a side-to-side cooling arrangement, with fan shrouds keeping the CPU air channel separate from the rest of the box.
This deviation from the BTX spec allows better use of space inside the system, Shuttle says. The chassis will have two other separate cooling zones, one cooled by a pair of fans at the rear of the case for SATA RAID drives, and the other for the chipset and graphics card cooled by the power supply fan. The fans on the SB81P follow Intel's new spec for Prescott systems, so they ramp speeds linearly as neededno more abrupt transitions from one fan speed to another. With more fans and three cooling zones, Shuttle says noise levels on the P series systems should be relatively low, especially for a system packing this much power.
Speaking of power, the SB81P uses a new 300W power supply unit, as well. Other notable new features include eight channels of High Definition Audio (using a Realtek codec) and a recessed Clear CMOS button on the rear of the unit, a la the Zen XPC. The SB81P is designed for tool-free operation, and a series of clip-on plastic rails allows for secure and easy hard drive mounting. Cable routing was also quite evidently given lots of attention inside the tidy P series; clutter is almost nonexistent. All in all, the P series looks like the most enthusiast-friendly XPC box yet.