back to 14nm —

Intel’s line of notebook CPUs gets more confusing with 14nm Comet Lake

Comet Lake looks good, but it seems like a confusing digression from Ice Lake.

Today, Intel is launching a new series of 14nm notebook CPUs code-named Comet Lake. Going by Intel's numbers, Comet Lake looks like a competent upgrade to its predecessor Whiskey Lake. The interesting question—and one largely left unanswered by Intel—is why the company has decided to launch a new line of 14nm notebook CPUs less than a month after launching Ice Lake, its first 10nm notebook CPUs.

Both the Comet Lake and Ice Lake notebook CPU lines this month consist of a full range of i3, i5, and i7 mobile CPUs in both high-power (U-series) and low-power (Y-series) variants. This adds up to a total of 19 Intel notebook CPU models released in August, and we expect to see a lot of follow-on confusion. During the briefing call, Intel executives did not want to respond to questions about differentiation between the Comet Lake and Ice Lake lines based on either performance or price, but the technical specs lead us to believe that Ice Lake is likely the far more attractive product line for most users.

Intel's U-series CPUs for both Comet Lake and Ice Lake operate at a nominal 15W TDP. Both lines also support a "Config Up" 25W TDP, which can be enabled by OEMs who choose to provide the cooling and battery resources necessary to support it.

Things get more interesting for the lower-powered Y-series—Ice Lake offers 9W/12W configurable TDP, but Comet Lake undercuts that to 7W/9W. This is already a significant drop in power budget, which Comet Lake takes even further by offering a new Config Down TDP, which is either 4.5W or 5.5W, depending on which model you're looking at.

Comet Lake's biggest and meanest i7, the i7-10710U, sports 6 cores and 12 threads at a slightly higher boost clock rate than Ice Lake's 4C/8T i7-1068G7. However, the Comet Lake parts are still using the older UHD graphics chipset—they don't get access to Ice Lake's shiny new Iris+, which offers up to triple the onboard graphics performance. This sharply limits the appeal of the Comet Lake i7 CPUs in any OEM design that doesn't include a separate Nvidia or Radeon GPU—which would in turn bump the real-world power consumption and heat generation of such a system significantly.

Comet Lake's Y-series makes a similar trade-off. Although Comet Lake's Y-series does offer significantly lower power consumption than Ice Lake's, it makes plenty of sacrifices to get there. Its all-core turbo frequencies are typically down about 400 MHz from Ice Lake's, the RAM drops from LPDDR4x-3733 to LPDDR3-2133, and (of course) no Iris+ graphics. We expect this will all add up to Ice Lake's Y-series performing much better than Comet Lake's, at a very obvious, seat-of-the-pants level in otherwise similarly configured systems.

Finally, Comet Lake does not support Intel's Deep Learning Boost, a limited extended instruction set that accelerates AI workloads based on vector neural networks. This extended instruction set was originally available in Cascade Lake series Xeon Scalable processors before moving down to the laptop with Ice Lake.

We're willing to give Comet Lake a pass on this one. Personal-assistant technology in the moderate-to-near future might begin taking advantage of INT8 instructions to significant effect, but for now, we don't think most consumers are likely to miss it.

One focus the two product lines share is an enthusiasm for integrated Thunderbolt 3 and Wi-Fi 6 support. That's probably because neither is built into rival AMD's current lineup. The Wi-Fi 6 support is punched up particularly hard, with an entire slide devoted to glowing claims from Netgear, TP-Link, and Comcast.

It's probably a mistake to get too excited about that Wi-Fi 6 support; independent tests of the current crop of Wi-Fi 6 routers do not support the wild claims of 300% improvements in throughput and latency made on this slide. More importantly, the real promise of Wi-Fi 6 was never single-device throughput in the first place—the real promise of Wi-Fi 6 lies in whole-network efficiency increases. Those increases come with OFDMA, which is described by Netgear itself as the biggest benefit to Wi-Fi 6. Also according to Netgear, the benefits don't kick in until you've got at least four Wi-Fi 6 clients operating simultaneously.

Conclusions

In a world that went straight from Whiskey Lake to Comet Lake, this lineup would look pretty good. But we have trouble seeing a real value for Comet Lake in a market where Ice Lake was just released. The low power consumption of Comet Lake's Y-series is interesting, but the 6C/12T i7-0710U is the only really tempting part of its U-series line—and in both cases, we expect that most consumers would be better served with Ice Lake's much higher-performance graphics and RAM.

This isn't the first time Intel has dropped a confusing mix of notebook CPUs on the market near-simultaneously. Some new eighth-generation Coffee Lake products, for instance, launched after the entire run of ninth-generation Coffee Lake and Whiskey Lake parts had finished. It's tempting to speculate that Intel needed this late Comet Lake 14nm refresh due to production limits on Ice Lake, but it's just as likely that this is simply business as usual in the Intel world.

Assuming pricing is similar, we see the Ice Lake product line as clearly superior to Comet Lake for most consumers. The confusion between the two lines could also represent a field Intel has left ripe for its rival AMD to sweep. Perhaps AMD will even finish the hat trick it began with Ryzen 3000 on the desktop and Epyc Rome in the server room.

Channel Ars Technica