We’ve been very interested in Intel’s upcoming laptop CPUs, codenamed Tiger Lake, since the company’s Architecture Day event in August. Tiger Lake’s official launch event earlier this month didn’t offer much red meat for anyone already up-to-date on the news—but today, we finally have our own hands-on test results to share.
Much as Intel did during Tiger Lake’s launch event, we’re going to focus heavily on Intel versus AMD in our own tests and analysis. In our opinion, the current generation-on-generation within Intel’s own lineup is fairly boring (yes, it’s faster than its old parts). Instead, the real question is whether Intel finally has an answer to AMD’s Renoir architecture—and the answer isn’t as simple as “yes” or “no.”
Our reference system has the top-of-the-line Core i7-1185G7 CPU, tuned for a 28W default TDP—although that, too, gets complicated. For now, we’ll just note that it’s the fastest Tiger Lake CPU to be announced. However, assuming one i7-1185G7 system is much like the next would be a mistake.
Our Tiger Lake reference system
Before we dive into the performance analysis, let’s get to know the prototype laptop supplied to us by Intel. The system was built by MSI and, in many ways, it likely resembles what will become MSI’s new Prestige 14 Evo retail system. That said, please don’t draw any definite conclusions about a final retail system—particularly the Prestige 14 Evo—from what you see here.
Intel warned us that this was a reference system, not retail-ready, and likely not tuned the way retail versions will be. The platform also almost certainly doesn’t have the retail port layout: this system has two USB-C ports, both on the left hand side, and absolutely nothing else.
The system also exhibited noticeable capacitor whine. If you have a good ear for electronics, you can actually hear the device “thinking” from the change in the faint, high-pitched noise as the CPU shifts in and out of turbo frequencies, which it does rapidly.
We also did not test and will not talk about the system’s battery life in this review. Again, this isn’t really a laptop to be reviewed—it’s just a platform that enables us to put the i7-1185G7 to the test. We did, however, check the system power consumption at the wall using a Kill-A-Watt meter. Desktop idle varies from 7.5W-8.2W, and peak consumption (as measured during the first several seconds of a Cinebench R20 run) is about 66W-68W.
Performance
At first blush, you’d think the quad-core, octa-thread Core i7-1185G7 in this reference system is a mostly even match for the octa-core, octa-thread Ryzen 7 4700U in our Acer Swift SF314-42. As tested the way the system ships, it generally runs a little slower on multithreaded CPU tests, and it’s noticeably faster on single-threaded CPU tests.
Core i7-1185G7 | Ryzen 7 4700U | |
Cores/Threads | 4C/8T | 8C/8T |
configurable TDP | 12W-28W | 10W-25W |
TDP as tested | 28W | 15W |
Base clock | 1.2GHz | 2.0GHz |
Boost/Turbo clock | up to 4.8GHz | up to 4.1GHz |
This already isn’t really a match to brag about—the Swift 3 wrapped around our Ryzen 7 4700U is a budget laptop that doesn’t have the best thermals, and the 4700U itself is roughly in the middle of AMD’s Renoir lineup. The 4700U is only second from the top in AMD’s U series, and there’s an entire H series for high-powered systems above that.
Of course, Intel has been getting sand kicked in its face for a while now, and seeing something like performance parity is refreshing, even if we have to compare the company’s top-of-the-line CPU in a high-powered reference system versus a middling-high AMD CPU in a budget laptop. The comparison still has problems we need to iron out, though.
CPU power consumption / thermal budget
Tiger Lake, unlike previous generations of Intel mobile CPUs, only has a few SKUs. This looks like a blessing for consumers, but it’s likely more of a curse. Laptop OEMs have an incredibly wide configurable range for each SKU’s TDP (Thermal Design Power).
This means that one i7-1185G7 system is likely to perform very little like another—so now your less-technical colleagues not only won’t pay attention to the difference between one i7 and another, they won’t notice whether the exact same i7 SKU is configured for TDP of 12W, 28W, or anywhere in between.
Any i7-1185G7 system can briefly reach maximum turbo frequency and hit a power-consumption max of upwards of 50W, but the system doesn’t stay there for more than a few seconds, before dropping clock enough to fall back to its configured TDP.
The length of time which the system is allowed to stay at the highest PL2 consumption is called “tau.” Tau, along with the TDP itself, is configurable by the OEM. We seriously doubt tau will be disclosed on the box or in the advertising copy for many systems—and it can potentially have an even bigger impact than the TDP. A laptop allowed to run at PL2 (and draw 50+W) for minutes at a time will perform considerably higher (and exhibit a hellaciously higher power draw) than a competing system with the same TDP but a tau of only a few seconds.
At its out-of-box defaults, Intel’s reference system—set on the middle of three notches in Windows 10’s “performance” slider, found when clicking on the battery icon in the toolbar—is configured for a 28W TDP. Sliding the performance slider to the left sets TDP to 15W. The tau on the reference system isn’t specified, but it appears to be roughly 25-30 seconds regardless of TDP, judging from our observations and Anandtech’s.
If you slide the performance widget all the way to the right, the TDP remains 28W. But tau, on the other hand, becomes governed by Adaptix, an algorithm that extends turbo time by dynamically regulating clock frequencies down when the CPU itself isn’t the bottleneck. In general, users who enable Adaptix can expect a modest multithreaded performance gain with a somewhat larger corresponding power draw.
We did not directly test Adaptix, due to very limited time available with the reference system.
Multithreaded performance
In its default configuration, with a 28W TDP and roughly 25-second tau, the i7-1185G7 reference system runs pretty much neck-and-neck with a Ryzen 7 4700U-equipped Swift 3. We see the same basic relationship among all systems on both Cinebench R20 and Passmark. Geekbench 5 flattens the differences between all the processors in general, but it puts the 1185G7 at the head of the pack.
However, we suspect many retail 1185G7 systems won’t be configured for a 28W TDP—they’ll likely be configured at 15W TDP, just as both the Ryzen 7 4700U in the Swift 3 and the Ice Lake i7-1065G7 in the Dell XPS 13 are. When we drop the reference-system TDP limit to 15W by moving the slider hard left, we see a significant drop in performance. It actually falls slightly below the Dell’s Ice Lake 1065G7 on Cinebench R20, let alone the Acer’s Ryzen 7 4700U.
Since the i7-1185G7 is the highest-performance SKU announced for Tiger Lake, we felt that comparing it to the Ryzen 9 4900HS in our Asus ROG 14 gaming laptop would only be fair. The 4900HS in the ROG 14 is running at 35W TDP, and it utterly dominates the Tiger Lake i7 in both Cinebench R20 and Passmark testing. https://arstechnica.com/?p=1707377