You could have some crude region locking if SGI US signs with a different key than SGI EU, and US servers will only run on 60hz power supplies and EU servers only run on 50hz (some pinball machines use this to reduce transatlantic resale) it's not hard to measure, but it would need an extra power supply pin and a zero crossing circuit. DC systems would have a different signing key. Japanese systems wouldn't be able to move across their 50/60Hz divide, etc.
That only region locks the motherboard. The CPU would only be locked after it has been used in the motherboard, not before, which necessarily means you already have the CPU in question. So there wouldn't be any barrier to CPU movement across regions.
As in for your example there isn't anything stopping you from buying a CPU from anyone, including US retailers, and using it in an SGI EU motherboard. The CPU itself isn't locked when new, this signing key locking isn't baked into the CPU at the factory. It happens when you plop it into the socket & fire it up for the first time.
> As in for your example there isn't anything stopping you from buying a CPU from anyone.
I can't buy a used cpu from an SGI US customer and put it in an SGI EU motherboard. I can buy a new CPU from anyone though, but then I can only sell it in-region.
> I can't buy a used cpu from an SGI US customer and put it in an SGI EU motherboard.
Correct, but that's less a region thing and more this just poisons all used CPUs.
As in you don't even know if an SGI US CPU will work in a different SGI US motherboard. There's no particular reason to assume all SGI US motherboard models will have the same signing key. Within the same model that'd almost certainly be the case, but if it's a different model, especially different chipset, I don't know why they would necessarily strive to keep the key the same across different firmware branches.
> I can buy a new CPU from anyone though, but then I can only sell it in-region.
Er, why? Nothing about this stops you from re-selling CPUs however you want. Or are you still talking about the used market here?
I'm not reselling a cpu without plugging it in and testing it. If it's DOA when my customer got it, and I didn't test it, I need to take it back etc. Of course, if it gets locked when I test it, now it's more likely to be DOA for my customer.
Used SGI to not pick a real vendor.