Zalman Trimon ZM-M220W review

News that cooling specialist Zalman was branching out into 3D monitors raised a few eyebrows at PC Pro - not least because of the technology's long association with those red and green cardboard glasses. But 3D methods have come a long way since the dark days of nausea and paracetamol after five minutes of viewing, and the ZM-M220W actually managed to impress us.

Yes, you still need to wear glasses - in the box, you'll find a standard pair and even some clip-ons for spec-wearers - but they basically look like normal, if not exactly catwalk-capable, sunglasses. The polarised lenses are aligned at different angles, and the screen itself has two polarised filters in front of it, so that your eyes are fooled into thinking what you're watching is true 3D.

Thus, unlike the old alternative method with its rapidly alternating frames, this technology is smooth and flicker free. It's also capable of very rapidly drawing a giggling crowd of journalists. Swarmed upon by at least ten people in our demonstration session alone, there wasn't a single complaint of dizziness and everyone managed to see the 3D effect straight away. And once Zalman left it with us, there were no problems keeping the experience going.

The secret, it seems, is to find the right eye level and stay there; left and right movement is fine, but lift or lower your eyes by mere centimetres and the image will blur. As such, it's all but restricted to the solo viewer - not a huge issue for PC gamers, but still a limitation of the technology in general. Still, the 3D effect is perfectly visible from a wide range of angles, as long as that all-important eye level is met.

But how effective is it? That depends largely on the source material. Dedicated 3D video material looks by far the most impressive - the test video had all sorts of specially chosen scenes to really showcase the technology. Whether it was a fish drifting out of the coral and towards our eyes, or a fancy-dress parade marching to highlight the extraordinarily effective depth of field, every scene was vividly brought to life. A few small details were less effective: bright lights hardly benefited from the 3D effect at all, so a fireworks display looked oddly flat and lifeless.

On the other hand, 3D games are a liberating experience - we still haven't tired of seeing laser bolts fly towards our eyes, and we were genuinely surprised by just how good the whole effect is in the most suitable games. But the effectiveness varies enormously by game type. First-person shooters - with all their wide spaces, looming buildings and ranged weapons - work brilliantly on the whole; strategy games such as Supreme Commander are a little too top-down for there to be much of a point in 3D. Around 40 games are being supported initially: see www.pcpro.co.uk/links/160zalman for a full list.

At present, Zalman is working closely with Nvidia to add games and get the drivers working as well as possible - there's no word on ATi. But it seems to be slow work, with only an older XP driver for cards up to the GeForce7-series at launch. Mid-December should see a Vista and 8800-series driver, and also a fix to some of the more noticeable 3D issues.

Text, for example, needs to be displayed in 2D to be readable, and in-game head-up displays can jar the effect and look out of place in the 3D world. There are also issues with performance. With two different images being beamed out to your eyes, the frame rate understandably takes a pounding. If your rig can't run Oblivion at top settings in 2D, say goodbye to it completely in 3D. We also had issues with the reflectiveness of the screen, which is so apparent you'll need complete darkness whenever you want to run in 3D - we found that any slight glimpse of our brightly lit reflection during play made us lose our focus, blurring the screen and making our eyes work harder.