> Mainland China is by far Taiwan's biggest trading partner.

That's true for most neighboring Asian countries. But I'm also guessing that most fabless customers are American. Sure, there are Chinese fabless chipmakers such as HiSilicon (Huawei), Tsinghua Unigroup, but nowhere as big as Apple, Qualcomm, or AMD.

Where else would Apple, Qualcomm, and AMD (don't forget Broadcom too) go for their cutting edge silicon? Samsung couldn't handle that demand. I think they can pretty much do what they want when it comes to maintaining their business with China.

Of course Samsung can handle that demand. They got plenty of capacity just laying around and ramp up more as needed.

I thought the majority of their production capacity is for memory and displays, which isn't just lying around ready to go for 7nm chip customers. And having plenty of unused capacity lying around seems unlikely to me considering the costs involved. They only got into fabbing other people's stuff seriously a couple of years ago, I know they have business from Global Foundries but I can't think of any others. I don't think there is anything "of course" about suddenly taking on that level of new business. Ramping up however many new plants is a huge deal, these chips are in full production right now.

Capacity aside, swapping vendor is a monumental task. They may not even have the packaging tech that's needed.

Either way, I guess anyone who actually knows can't say.

Samsung has been running custom foundry business since 2005 when it started designing and fabb'ng Apple's mobile AP used in the iPod and iPhones until around ~2013 when Apple finally developed their own custom AP after PA-semi and Intrinsity acquisitions. QCOM and AMD have been with Samsung on and off for years now.

https://semiwiki.com/semiconductor/259664-samsung-foundry-up...

Global Foundries a licensee of Samsung's 14nm and, along with IBM, they were members of Common Alliance.

> swapping vendor is a monumental task. ...

Sure, that's what everyone said until Apple went dual-sourcing with TSMC 16nm and Samsung's 14nm.

I specifically didn't talk about when they started their foundry business. I specially was talking about 2017 when they started trying to become an serious option for fabless companies.

Yes, and it is still a monumental task, nobody is saying any different now. Apple must have been in a tough spot with their yields but that's what you get when you are first out the door. It's incredible how quickly they start shipping the new tech.

> I specifically didn't talk about when they started their foundry business. I specially was talking about 2017 when they started trying to become an serious option for fabless companies.

Sure, if you believe Samsung LSI got serious about foundry service only since 2017, you know nothing about Samsung's foundry business at all, which is why the brief introduction was necessary.

Because the main reason Taiwan is not part of communist China is it has military protection from US?