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Will the 9th Gen Mobile CPUs positively affect thunderbolt performance?  

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(@chandler_price)
Active Member

Since the recent release of the 9th gen intel mobile CPUs, I have noticed on their slides they mention thunderbolt 3 being directly connected to the CPU. I was wondering if there was any idea how thunderbolt 3 performance might improve, if at all on these mobile CPUs, and what kind of controller we could expect them to be using, if they are even using a controller at all? Sorry I am somewhat unfamiliar with these topics, and most tech sites I follow have only mentioned the native TB3 support as an after-thought.

This topic was modified 1 month ago

Pending: Add my system information and expected eGPU configuration to my signature to give context to my posts

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Posted : April 25, 2019 3:58 am
nando4
(@nando4)
Noble Member Admin

The 9th gen mobile H CPUs have been released. These now integrate a TB3 controller on the PCH for which I' guestimate now require better cooling than their older 8th-gen versions.

8th gen H CPU PCH chips were often not cooled leading to throttled throughput as @itsage found here:

Seeing numerous reports on lower-than-expected eGPU performance on 8th generation H-CPU hosts, @nando4 and I have been looking into the culprit. The Dell XPS 9570 in this build is one that experiences low performance during eGPU use. Nando tested a Dell Latitude 5591 and observed the same behavior. We discovered there's an oversight in cooling the PCH through which Thunderbolt 3 connection is attached on these laptops.

As seen in the photos above, the PCH chip of the XPS 9570 has no cooling. Dell had installed a thermal pad for the NVMe SSD on the other side and it draws heat onto the bottom case. I replicated this same cooling for the PCH with a 2mm-thick thermal pad square. The chipset sits lower than SSD and the added 2mm pad didn't quite reach the aluminum surface of the bottom case. A more permanent cooling solution is to use 3mm+ thermal pad with a wider contact surface.

This isn't really an issue for the more common U CPUs since they integrate the PCH on the CPU die itself, which is cooled. Should they too now have a TB3 controller then it's one less systemboard chip for the manufacturers to accomodate.

eGPU Setup 1.35    •    eGPU Port Bandwidth Reference Table    •    Several builds
2015 15" Dell Precision 7510 M1000M + GTX 1080 Ti @ 32Gbps-M2 (ADT R43SG) + Win10

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Posted : April 25, 2019 4:28 am
(@chandler_price)
Active Member

Wow thanks for the quick reply. I had no idea the PCH was integrated into the die of U series chips. I will keep an eye out then for benchmarks/buildguides with the 9000 series chips to see how they fare, and if these components receive more cooling. I was looking to purchase a laptop in the near future, but was holding out for a platform that might have a better EGPU setup.

Pending: Add my system information and expected eGPU configuration to my signature to give context to my posts

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Posted : April 25, 2019 4:32 am