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HP Slate 21 review


  • Speedy boot and wake times
  • No worries about Windows malware


  • Laggy touchscreen
  • 8GB is too little local storage space
  • 1GB isn't enough RAM
  • Browser is optimised for mobile sites

The HP Slate 21 is a product in search of a certain user. That user pines for the kludgy early days of mobile operating systems when only certain things worked right, and only if you were patient. It's an all-in-one desktop PC that runs Android Jelly Bean, and while that's an admirable trait for the anti-Windows folk, in reality, using the Slate 21 is a painful experience that only really works for very few tasks, and ultimately leaves you asking why this product exists.


The white plastic chassis of the Slate 21 measures 530 x 67 x 355mm (WxDxH), which is relatively compact for an all-in-one desktop PC. The system comes with an easel-style arm on the back, which can tilt down from 15 to 70 degrees, which puts it in a position where using the touchscreen is comfortable for either seated or standing users.

The 21.5in touchscreen has a 1,920 x 1,080 resolution IPS panel and two-point optical touch sensor. This is similar to, if less sophisticated than, the five-point optical sensor in the HP Pavilion TouchSmart 23. In use, the touch sensor works okay for games like Fruit Ninja, but at times it seemed like the sensor wasn't tracking our fingers quite fast enough. The screen itself is very clear and visually flawless, but as you'll see below, that high resolution introduces its own problems.

The system comes fitted with an Nvidia Tegra 4 processor, 1GB of DDR3 system memory, 802.11 a/b/g/n Wi-Fi, and 8GB of SSD-based storage. It runs Google's Android Jelly Bean OS (4.2.2), rather than Microsoft's Windows 8, which is commonly found on budget all-in-one PCs (like the HP Pavilion 20, for example). This introduces benefits and drawbacks. The major benefit is that the Android operating system is efficient, so boot times and load times are fast. Android also fits on the small 8GB SSD, and another benefit is that the system isn't susceptible to Windows-based viruses and malware, though any web-based phishing attempts can still trip you and your digital ID up. The big drawback to this setup is that the system isn't Windows compatible, so you can't use the millions of programs written for Windows PCs.

Another drawback is the fact that the system's browser defaults to mobile versions of websites, most of which look ridiculous when viewed in landscape mode instead of portrait mode. Also, mobile websites tend to blow up the size of the typography on the site, so you'll be scrolling a lot. This is an obvious (and ugly) disadvantage when you have a 21in 1080p HD screen to work with.

For example, when we tried to get to Facebook on the Slate 21, it only let us on to the mobile version of Facebook, which is optimised for 4in screens. Each post and picture on Facebook is blown up to full-screen width, which means you can see spinach in your relative's teeth since their faces are blown up to larger than real life. This was the case in the Android browser, Chrome, and when using the native Android Facebook app. As many tablet users know, you can't force the desktop version of Facebook to show up unless you use a third-party browser that fools Facebook into believing it's a real desktop browser (like IE).

Matters worsened when we tried to access heavy HTML 5 websites, for example the Museum of Mario site (, which dropped frames, had background audio issues, crashed both browsers, and generally didn't work right. We're surmising that this is due to the paltry 1GB of system memory on the Slate 21, since the website worked fine on an Acer C7 Chromebook which has 4GB of memory. Also, while Netflix worked fine using the Android app (which doesn't support multiple users yet), we struggled playing video on other fronts due to the lack of Flash and Silverlight support.


We ran our standard set of CPU, graphics, and browser benchmarks on the Slate 21 and got very good results, similar to and even a little better than the HP SlateBook x2, which was previously the fastest Android tablet we've seen. A 600 millisecond result in Sunspider and 2,847 in Browsermark 2.0 is an impressively fast performance for an Android tablet. However, remember that "real" desktop PCs are in a whole other world – the two-year-old 2.2GHz Core i7 MacBook Pro used to write this review achieved 180ms in Sunspider and 4,661 in Browsermark in Chrome. The Slate 21 is only first in a race where everyone else has shot themselves in the foot.

The typical reason a device maker picks ARM processors rather than faster Intel chips is power consumption – at the very low power levels demanded by phones and tablets with limited batteries, ARM outperforms Intel. But the Slate 21 will always be plugged into a wall; it makes zero sense for HP to have gone with a processor that prioritises power management over speed.

It also makes no sense for HP to have only loaded 1GB of RAM in here – we got a low memory warning during one benchmark run and had to manually quit a bunch of apps. The pathetic 5GB of free storage can easily be eaten up by a few large games and a movie, so you'll be turning to the full-size SD card slot as well. It's the worst designed SD card slot we've seen, because it's not clear which way the card goes in, and it's very easy to stick the card in backwards – at which point we had to pull it out with pliers.

HP adds its own media playback apps to Google's, and they played all our test files just fine. The Slate 21 handled MP3, AAC and OGG audio files, as well as DivX, Xvid, MPEG4 and H.264 video at up to 1080p resolution, as we'd expect from any Nvidia Tegra 4-equipped device.

Android problems

However, software compatibility is a problem here, in more ways than one. Many high-end Android games, even ones featured in Nvidia's Tegra Zone store, don't run on the Slate 21. You can't download Need for Speed: Most Wanted, Asphalt 8, Need for Speed: Hot Pursuit, or Dead On Arrival 2. Google's store says they're incompatible.

Other games have serious control problems; obviously, anything designed to work with accelerometer controls, or any game which assumes the position of your thumbs, is unplayable. That means there's no way to steer your plane in Fractal Combat, for instance. RPGs with touch cursor pads and touch-oriented combat interfaces are also really awkward to play. Games with controller options, like Reaper, can be operated with a keyboard and mouse, and some touch games, like Where's My Water and Fruit Ninja, work fine on the touchscreen. That said, if you play these for a while you'll have uncomfortable arm extension problems.

Kingsoft Office reveals another issue: Nobody on Android is designing for 21in screens. The default type size in the built-in office app is huge – it's like you're typing on an old VIC-20. Yes, you can reduce it, but the point is that most app UIs – including this one – are designed for 4in to 5in screens, not 21in screens. Everything looks inflated.


HP’s Slate 21 is an interesting idea, but Android and its software simply aren’t ready for this form factor yet. If you want an Android device with a large shareable screen, our recommendation is the Samsung Galaxy Note 10.1 (2014 Edition). And if you want a 1080p HD all-in-one PC, there are better options out there in the Windows camp which are budget-friendly enough, if not quite as cheap as HP's offering.

Maybe you just want to watch Netflix on a big screen? Then grab an Apple TV or Roku box and hook it up to your HDTV. Need a fully functional web browser, and that's it? Get an Acer C7 Chromebook for a lot less money.

We do applaud HP for trying new things here, but for now a myriad of other devices are better alternatives than the Slate 21.


Manufacturer and Model

HP Slate 21


Nvidia Tegra 4


Android 4.2.2

Screen Size


Screen Type

LED Widescreen




Touchscreen All-In-One

Storage Capacity