Thoughts on software-defined silicon [LWN.net]

Thoughts on software-defined silicon

Posted Feb 19, 2022 19:07 UTC (Sat) by Cyberax (✭ supporter ✭, #52523)
In reply to: Thoughts on software-defined silicon by khim
Parent article: Thoughts on software-defined silicon

> It would cost you a lot. If you would stop selling $299 Ryzen 5 5600X (which is, essentially, $449 Ryzen 7 5800X with two cores disabled) and would start selling Ryzen 7 5800X for $399 instead of having these two… you would lose both on people who were ready to spend $449 and on ones who were ready to buy something for $299.

Except that you can undercut Intel and sell Ryzen 7 5800X for $299 and immediately crush Intel. Otherwise Intel will just push you out with cheaper and faster CPUs.

In reality, cores are usually locked because they fail internal QA - this is indeed a perfectly valid strategy.

> I took example from AMD book, not Intel book to show that as competition grows more acute the need to disable features and sell crippled product grows, not diminishes. Market segmentation is powerful tool.

Not following. Once the competition starts biting, there's a pressure to unlock more and more features on the low-end of the spectrum.

to post comments

Thoughts on software-defined silicon

Posted Feb 20, 2022 0:40 UTC (Sun) by khim (subscriber, #9252) [Link]

> Except that you can undercut Intel and sell Ryzen 7 5800X for $299 and immediately crush Intel.

Seriously? Immediately crush Intel? Weren't you celebrating 25% market share which AMD achieved in four years after introducing CPU which totally kicked Intel's ass?

If you would start selling Ryzen 7 5800X for $299 the only thing you would achieve would be stiffing your own R&D. Which would mean that your next CPU would be worse that CPU of competitors and you would “crush” yourself instead.

> In reality, cores are usually locked because they fail internal QA - this is indeed a perfectly valid strategy.

How do you know? We know for a fact from the times when it was possible to enable them that they were perfectly functional back then. We know from sales figures today that it's, most likely, still true today (Ryzen 5 5600X sales are much higher than Ryzen 7 5800X). Nope, these cores are not locked because they fail QA. They are locked to be able to sell CPUs at different price points.

> Once the competition starts biting, there's a pressure to unlock more and more features on the low-end of the spectrum.

Where would that pressure come from? It's zero-sum game. We only have two competitors (in mobile space there are more, but still not that many). If you stop offering CPUs at different price points then you wouldn't, suddenly, get more money from selling more CPUs because you couldn't produce more CPUs at the snap of fingers. You pay a lot to ramp up capacity and it happens slowly. If you would deprive yourself from receiving more money they you would just fail to produce enough CPUs, leave money on the table and would lose in the next round of competition.

That's how we ended up with just two manufacturers of x86 CPUs BTW.

Thoughts on software-defined silicon

Posted Feb 20, 2022 0:44 UTC (Sun) by excors (subscriber, #95769) [Link]

> Except that you can undercut Intel and sell Ryzen 7 5800X for $299 and immediately crush Intel.

Why would you want to crush Intel in the lower-end market segment where (per the economy seat analogy) their profit margin is approximately zero? The production cost of your 8-core chip will be similar to their 8-core-with-2-perfectly-good-ones-disabled chip, so you'll make no profit either. And now you can't do any market segmentation yourself, because you're already selling your most powerful chip for no profit. That seems much worse than copying Intel's segmentation strategy and getting a small share of high-margin segments.

Thoughts on software-defined silicon

Posted Feb 21, 2022 4:35 UTC (Mon) by timrichardson (subscriber, #72836) [Link] (1 responses)

IN pricing theory, you want to extract the maximum value. If you sell a product at only one price, you are forced to compromise at both ends: there are potential customers who would pay above your marginal price, so are potentially profitable but don't buy because your offered price doesn't meet the value they see in the product, and you leave money on the table from customers who have more value in your product than what you charge; they would have paid more if you asked, but you didn't.

The conventional answer to is create differentiated products at different price points. Intel does this, nothing new. It is commonly accepted that this is something like an happy accident of the variation in how CPUs are made. A comment above says that this is greatly exaggerated but even if not, the distribution of different working cores is not a random accident: it would be a deliberately chosen manufacturing strategy affected by how the production process is configured. I doubt that Intel or AMD is very surprised by the output they get, and I expect they could tweak their production process to avoid nearly all locked cores, although at the cost of lower total output ( I have some manufacturing experience behind that comment, but it think it is not a controversial statement). The difference between accepting binned manufacturing output or achieving the same thing with software seems really invisible to me. I find it ironic that a computer science community is having trouble with the concept of abstracting hardware into software.

Thoughts on software-defined silicon

Posted Feb 21, 2022 13:40 UTC (Mon) by gnb (subscriber, #5132) [Link]

Whether the difference is really invisible depends a lot on the implementation: are the feature enablements being sold liable to expiry or revocation by the vendor? If so the difference between that and actually owning the feature seems pretty clear-cut. I suspect what is making a lot of commenters on this article uneasy is a suspicion that this is part of a move to a rental model.