[The Exiled]

Intel 11th Generation Core Tiger Lake-H performance review: Fast and Power Hungry

In the context of today’s Tiger Lake-H reference laptop and system, the one thing we must preface the rest of the review is the power settings the laptop came in and the resulting behaviour and thermal characteristics of the Core i9-11980HK SKU we’ll be reviewing today. Intel’s reference laptop, out of the box as delivered to us by Intel seemingly was set up with no PL1 limit, or at least what we suspect is the maximum cTDP limit of 65W of the i9-11980HK. Generally speaking, this is no surprise as TGL-H is targeting the high-power desktop replacement laptop market which tends to come with capable and extensive thermal dissipation designs. At first, we started running our tests on the platform in this default reference setting, representing what we had hoped being the best-case scenario for the chip and platform, until we discovered some concerning thermal behaviour when under full load.

The worrying behaviour starts happening after around 2 minutes of load: we indeed see the CPU package generally trying to limit itself to around 65W, however it’s not a constant steady state, with very obvious large fluctuations between 65W and 35W. Looking at the temperature, we’re seeing maximum load figures in excess of 95°C, with some 96°C peaks in our coarse sampled data. What seems to be happening here is that the CPU is thermal tripping between the 65W and 35W states, unable to sustain the 65W state for any amount of prolonged time. We’ve confirmed that this throttling and power and frequency fluctuations happen on several workloads, and the only conclusion we can come to is that the reference system simply doesn’t have an adequate enough thermal dissipation solution to effectively enable the 65W cTDP mode of the CPU.

Unfortunately, we don’t have Intel’s previous generation H-Series processors in house for a direct generational comparison, but the next best thing is the 11980HK’s nearest competitor, AMD’s Ryzen 9 5980HS. This latter chip comes with a 35W TDP which is 10W lower than the new TGL-H SKU we have in house right now, and we see an obvious difference between the chip’s long-term thermals and power, ending up at different levels after some while. The Ryzen 9 has a prolonged 300s semi-turbo state where it sustains 42W power until thermal saturation of the laptop. During this period, with similar power consumption to the 11980HK and also quite similar thermal results of around 80-83°C, both platforms seem to be quite similar – except for the fact that AMD Zen3 cores able to operate at all-core boost frequencies of around 4GHz, while the Willow Cove cores of the TGL-H system operate at around 3200MHz and below.

Due to AMD’s recent shift to a 8-core core complex, Intel no longer has an advantage in core-to-core latencies this generation, and AMD’s more hierarchical cache structure and interconnect fabric is able to showcase better performance. In terms of the overall performance, the 45W 11980HK actually ends up losing to AMD’s Ryzen 5980HS even with 10W more TDP headroom, at least in the integer suite. The area where the new TGL-H and particularly today’s tested Core i9-11980HK performs extremely well and is undoubtedly the leader among mobile x86 CPUs, is in its single-threaded performance.

The new Willow Cove CPU cores alongside with the extremely high 5GHz boost frequencies achieved by the chip means that it manages to differentiate itself to even AMD’s more recent Cezanne Zen3 based Ryzen Mobile chips. Where things are quite as straightforward, is the multi-threaded performance, as this is where we have to mention TDPs, power limits, and just the result of the Intel reference platform laptop we’ve tested today. Intel’s new 10nm SuperFin process had promised to finally outperform the mature 14nm node – while we couldn’t get to a definitive conclusion based on the initial 4-core Tiger Lake designs due to the smaller core numbers, here in 8-core vs 8-core scenario at their latest microarchitecture implementations, we can still see that Intel is lagging behind in terms of efficiency and AMD’s 7nm CPUs.

Izvor: AnandTech i HotHardware