The Z520 Atom processor runs at 1.33GHz and sports 512KB of Level 2 cache. Atom chips are only single core, but they do incorporate Intel's Hyper Threading Technology, so they can process two threads simultaneously. As such, Windows will report two 1.33GHz chips being present in device manager, but while Hyper Threading can definitely improve system performance in multi-threaded environments, it's no substitute for a true multi-core setup.
The CF-U1 ships with 1GB of RAM, which could prove to be a problem if you opt for the Windows Vista build, but thankfully Panasonic also offers Windows XP, which is funnily described as a "downgrade". Microsoft may well want Panasonic to start pushing Vista out on its ToughBooks, but I know for a fact that the majority of ToughBook customers still want XP.
The combination of Atom CPU, SSD and Windows XP makes for a very swift device. In fact everyone who picked up the CF-U1 was surprised at how responsive it is, with none of the hourglass churning that's often associated with UMPC devices. Although raw performance doesn't tend to be the most important factor for potential ToughBook users, generally swift operation will only be seen as a good thing.
Just picking up the CF-U1 fills you with supreme confidence in its ability to survive almost anything. It has that kind of indestructible feel to it, that used to reserved for Land Rovers and Tonka toys. This initial feeling continues when you examine all the ports and sockets surrounding the device. All the ports are hidden behind sliding doors that snap shut with a waterproof seal - the locking mechanism is also up to Panasonic's usual standard, ensuring that none of these flaps open accidentally when you least want them to.
On the right of the CF-U1 are two flaps - one hides an SD card slot, while the other protects the headphone and microphone sockets. Also on the right was the stylus, although this can be moved to the left if you prefer to house it on that side. On the top edge is a flap that hides a USB 2.0 port, while on the left, the final flap protects the power socket. On the top edge you'll notice a sensor behind a Perspex cover - this is a barcode scanner, making the CF-U1 ideal for warehouse workers that need to keep on top of stock levels.
The front of the CF-U1 is dominated by the 5.6in TFT screen, which is obviously smaller than any notebook or even netbook would offer. However, Panasonic should be congratulated for equipping such a small screen with a usable resolution - 1,024 x 600 to be precise. Considering that the vast majority of web pages are rendered at 1,024 pixels wide, the CF-U1 will be able to display most websites (including TrustedReviews) without the need for sideways scrolling. That's quite an achievement for a screen so small. If you're worrying that everything will look too small on the CF-U1, don't. I found the screen easy to read and completely usable, but if you do find yourself squinting, Panasonic has included a hardware rocker switch to zoom the image in and out. This means that if you're reading something that's a little too small, you can simply zoom in and then zoom back out when you return to the desktop.