Just about every all-in-one PC hides the internal components from the owner, and cannot be easily upgraded after purchase. The Z1 is uniquely different in this respect. The unit can be folded over on its hinge, pushed down and opened via two latches at the bottom. The screen then lifts away from the rest of the unit, exposing the innards (see below). See also: Group test: what’s the best all-in-one PC? The hard disk, 400 watt power supply, memory, main system fan and graphics card can be removed with attached handles. You’re given easy access to the motherboard and its two full-length mini PCIe slots. There’s also a disk bay that lets you fit either one full size 3.5in SATA disk, or two 2.5in drives. The only restrictions are the MXM (mobile PCI Express) graphics card connector, which means you can’t just use a retail graphics card. CPU upgrades are similarly restricted to the processors available during the order process. Although the first-generation Z1 was a clever piece of engineering, it was slightly limited by its middling performance compared with desktop workstations. This time, HP has given the specification a major boost, with the option of a Quadro K4100M, quad-core 3.4 GHz Intel Xeon E1245 v3 processor, 802.11ac wireless, 20 Gb/s Thunderbolt 2 connectors for use with displays or external storage arrays, and an mSATA SSD. The front of the Z1 is made from black plastic, with a silver metal backing plate. Four speakers sit underneath the screen, and there’s a 1080p webcam at the top. A slot-loading optical drive is on the left-hand side, while on the right are two USB 3.0 ports, either one or two Thunderbolt 2 connectors, two 3.5mm analogue audio connectors and the power switch. The rest of the ports are inconveniently placed behind the unit, requiring some manoeuvring to access. Here you will find the power connector, ethernet port, four USB 2.0 ports, DisplayPort, three more analogue audio connectors and one for digital audio. The 2560 x 1440-pixel IPS display is top-notch. We measured a maximum brightness of 440 cd/m2, with no more than 4 percent deviation across the panel. It managed 100 percent sRGB, 84 percent AdobeRGB and 76 percent NTSC coverage. You can also choose a touch-sensitive version if you wish, although its colour accuracy is unknown. We received a high-end configuration of the Z1 G2, with a high price to match, but less expensive Quadros and Core i3 processor options are available. The Quadro K4100M in our sample is a mobile GPU, roughly equivalent to an nVidia GeForce GTX 770M, with 4 GB of video memory, 1152 shaders and a 256-bit memory bus. Quadros aren’t the best choice for games of course, but we tried some anyway. The Tomb Raider benchmark dipped below 30 fps at 1080p on Ultimate detail, and only hit a constant 60 fps after reducting resolution to 720p on detail to High setting. But the professional graphics processors excel at CAD or digital content creation, with CUDA acceleration and certified drivers to provide consistent performance. In other tests, the Z1 showed itself to be a highly capable machine, able to hold its own against desktop workstations despite its mobile graphics card. It chewed through Cinebench 15 benchmarks, managing 107 fps in the GPU test and 661 points in the CPU test. SPECViewPerf 12 and 3DMark results were also excellent, either matching or beating the performance of a recent desktop workstation that had a desktop Quadro K4000 graphics processor and lower-clocked Xeon processor. Our storage and wireless performance tests produced middling results. The Micron mSATA SSD managed 429 MB/s sequential read speeds, but only 232 MB/s write speeds. And its 221 MB/s random 4 k write speeds (QD=32) wasn’t as impressive as the fastest flash drives we test. The Intel 7260 wireless card is a dual-antenna adaptor, so we didn’t expect the best 802.11ac performance possible, but 392 Mb/s is still far better than 802.11n. The 1 TB Velociraptor hard disk spinds at 10,000 rpm and hit 212 and 208 MB/s sequential read and write speeds, some of the fastest speed you see from a hard disk. Another feat of the Z1 is its low power consumption. When idling, the Z1 G2 consumed 76 watt of power, less than the amount guzzled by some older large displays alone, and when running benchmarks, this climbed to a still moderate156 watt. Impressive. The Z1’s bland appearance and extreme bulk are our only minor criticisms. Its 21.3 kg weight is fairly back breaking, and its folding and opening mechanism may be unique, but is not exactly elegant. Pushing it down into place needs a hard push, and the unit is many orders of magnitude thicker than an iMac, since the large case is required to provide enough space to access the internal components. The included chunky wireless keyboard and three-button mouse aren’t particularly exciting designs either.
