Testing
It’s been a long while since we reviewed a laptop on Bit-Tech so we’ve limited data of our own for comparison. However, we do have this model’s predecessor to go on. Indeed it was this comparison that most intrigued us: seeing just how much of an upgrade Haswell is over Ivy Bridge in performance laptops.

Battery Life
The first, and arguably foremost, way in which we tested this was with battery life. We used the industry standard battery benchmark MobileMark, which runs a simulated workload using real programs. Its productivity test simulates browsing the web, word processing, watching video, image editing, checking emails as well as idle time, giving as true a representation of general usage as possible.


With improvements to battery life being among the biggest gains for ultra-portable laptops using Haswell, it’s something of a disappointment to see a gain of only 13minutes for the P503 over the P502. Clearly battery life isn’t a primary concern with such machines but had the battery life improved from, say, the P502's three and a half hours to five hours, it would’ve been a real usage-changing difference. As it is, it’s a token gesture at most.

CPU Performance
While battery life didn’t improve all that much, where we did see much more substantial gains was in CPU performance. Running our custom benchmark, we saw the image editing score rise from 1600 to 1912 (a 20% gain) while video encoding had a 15% gain.




The story is much the same when it comes to that great multi-threaded benchmark Cinebench which showed a 17% improvement. As a trade off we’d certainly rather have even greater battery life and the same performance, given how decent the P502’s figures already are, but on balance a gain in both departments is nice to see.

GPU Performance
Moving onto gaming, we fired up Dishonored and cranked the settings to maximum to see just what sort of performance you can get from a mobile chipset, and the answer is rather a lot. To get nearly 80fps running at 1,920 x 1,080 with FXAA is no mean feat, out pacing the likes of the desktop GTX 670. The Nvidia GTX 780M may not be a true upgrade to the GTX 680M of last year but it still proves to be quite the powerhouse.


Conclusions
The Schenker XMG P503 Pro does precisely what it sets out to: it delivers top of the line performance without the frills. On top of this it offers unprecedented levels of configuration, allowing the end user to specify exactly what they want - it’s an astonishingly powerful 15.6in machine that can be made even more so if you want to splash even more cash.

However, in this pursuit for cut-price customisation, Schenker XMG/Clevo really has put all other considerations aside. Bar a few token gestures like a backlit keyboard it's rather lacking in niceties, compromising on design, dimensions, weight and even the quality of the likes of the screen and keyboard. That’s not to say they’re bad - far from it - but simply that they are only average at best.

Whether that compromise is the right one is ultimately a personal decision but we can’t escape the feeling that when spending well in excess of £1,500 on a laptop the basics like the keyboard, speakers and screen should be of a high standard, especially given how the quality of such components has improved so dramatically in recent years, driven by the boom in tablets and ultrabooks. Sure the price would rise further but for, say, £200 extra we think most buyers would appreciate the extra quality.

That point aside though, if you're looking for the most powerful 15.6in laptop around, then the Schenker P503 Pro is well worth considering.

Also, what this system has again demonstrated is how beneficial it is to buy a Haswell-based laptop. Whether you’re after the most performance or the longest battery life, it really does deliver making now a great time to upgrade. Well I do need a new ultrabook…

Update: This article has been modified since originally published. It has come to our attention that our previous comparison to a Scan laptop was unfair as the two systems use slightly different chassis. The Scan system physically doesn't offer the upgrade options available here. With this taken into account we have adjusted our score and wording to reflect the fact that this system does indeed offer competitive pricing.