WEBVTT

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When you think of high-performance CPUs, you probably think about how we've shrunk transistors

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over the years to the point where we can fit an insane number of them onto just one chip.

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But did you know that the substrate the processor die sits on is also very important?

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Not only do substrates give the delicate die structural support,

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they also carry signals and connect the die to other parts of the system.

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On most CPUs, the substrate is primarily made from epoxy and fiberglass,

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that's plastic reinforced with woven glass fibers. But Intel is moving towards using substrates that are based on refined glass instead.

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It's more like what you picture when you think of glass, like actual glass.

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These glass core substrates have advantages that can allow for higher performance than the current

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fiberglass and epoxy organic substrates that have served us well since the early 2000s.

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One big one is how glass substrates react to heat.

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Because chips are often heating up and cooling down as different kinds of workloads are put on them,

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organic substrates stretch and relax in unpredictable ways.

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Actual glass is stiffer and a lot more resistant to thermal warping.

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This extra stability means you can put more routing holes in the substrate for extra power

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and data connections, not to mention better signal integrity,

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which is increasingly challenging as our transistors become smaller and smaller,

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no matter what we do to stop them. For a practical example, think about how top-end server processors suck down hundreds

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of watts of power, but run at only around one volt.

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If you remember your high school physics, this means you're having to push through

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lots of current at one time, which is pretty inefficient and leads to some of that power

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getting lost. Because glass is more stable than organic substrates at higher temperatures,

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you can put in a greater number of data and power connections,

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which improves both signal integrity and power efficiency.

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It's a pretty cool feat of engineering, but what does this actually mean for you,

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the average computer enjoyer? Part of the reason Intel is so concerned about power efficiency and signal integrity

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is due to how much electricity and data goes through data centers that do lots of AI processing.

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And since most of us use some kind of cloud AI service these days,

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switching CPU substrates is one of several developments that will help ensure our AI

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capacity can continue to grow. In fact, the new substrates lead to a theoretical doubling of the data rate between two chips

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in a data center, and will even help with communication between chiplets on the same

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package due to allowing smaller distances between the bumps that connect the substrate to the die.

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Glass is also easier to flatten out than organic substrates,

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which makes manufacturing significantly simpler. And combined with the advantages we've already discussed,

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chip makers should end up being able to put more processing dies on one chip,

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as well as make those dies larger, giving us more compute power per package.

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Just getting better and better. But are glass substrates also going to be coming to the CPUs we have at our home PCs?

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The short answer is yes, but we may be in for a bit of a wait,

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as the limitations that glass substrates are meant to address

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are more of a concern for data centers right now. Intel is looking at rolling out data center chips with the new substrates in the second

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half of this decade, while we'll likely see consumer chips towards the end of the decade.

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Until then though, there's nothing wrong with using fiberglass. I mean, it's good enough for surfboards.

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Hey, what are you doing here at the end of the video?

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You rascal. Hey, thanks for watching.

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Keep that. Like the video if you liked it, dislike it if you disliked it,

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