Qualcomm’s answer to the iPad Pro and ultra-portable PCs is the Always-Connected PC (ACPC). When it debuted, the ACPC platform was powered by the same mobile chips that power the best Android phones out there. This was in December 2017. In June this year, Qualcomm announced a dedicated chip for its ACPC platform and promised a significant performance bump. Unfortunately for Qualcomm, initial leaks indicate that the bump may not be as significant as promised.
The original ACPC platform was powered by the Snapdragon 835. While a powerful chip, it wasn’t, at the time, powerful enough to handle a Windows 10 PC. Our initial impressions of the ACPC was more one of surprise that the system actually worked rather than an appreciation of the performance on tap, which there wasn’t much of.
The SD835-powered PCs were functional and offered incredible battery life — some have reported not needing to charge the laptop even after a week of use — but the Windows experience itself wasn’t exactly lag free. Basic tasks such as Word, PowerPoint and web browsing ran tolerably well.
In June, the Snapdragon 850 was announced and it promised a performance boost of 30 percent over the previous 835 Mobile PC platform. Also included were promises of 20 percent better battery life and LTE speeds. The 850 can best be described as a faster 845 (the same chip that powers the OnePlus 6) that’s better optimised for Windows 10.
A recent leak on German site Winfuture.de, however, reveals that the promise of a 30 percent performance bump may have been, as with most marketing material, a rather ambitious claim.
As can be seen from the graphs above, the overall performance gains are a decent 23 percent in single-core performance and a mere 7.3 percent in multi-core. This is nowhere near the promised 30 percent.
This is, however, only part of the story. Yes, the performance gains are not that great, but benchmarks are only part of the story. Apple’s 12-inch MacBook (2017) managed a score of 3522 and 6656 in the same benchmark. The recently launched Surface Go managed a measly 1698 and 3899. In both cases, you won’t find people complaining so much about performance.
And speaking of performance, the issue with Qualcomm’s ACPC is more one of optimisation than raw horsepower. Qualcomm’s Snapdragon platform is built on the ARM architecture whereas Windows is optimised for x86. Explaining the differences between the two architectures will take too long, suffice it to say that ARM is designed for ultra-low power operations and is relatively inflexible. x86 is more power hungry, but also far more flexible in what it can do. This is also part of the reason why you can still use a 5-year old PC, but a 5-year old phone is as good as dead.
For ARM chips to perform well, software needs to be properly optimised. Regarding the 850 performance figures, we’ll just quote AnandTech here, “With the goal being parity with the incumbent, users had an idealised view of what this should be, so when x86-focused benchmarks underperformed, negative comments resulted.”
While the raw performance numbers are indeed disappointing, we suspect that the performance gains that Qualcomm is talking about will show themselves in a more fluid Windows 10 experience rather than in raw performance figures.