The Prelude

As Intel got into the chipset business it quickly found itself faced with an interesting problem. As the number of supported IO interfaces increased (back then we were talking about things like AGP, FSB), the size of the North Bridge die had to increase in order to accommodate all of the external facing IO. Eventually Intel ended up in a situation where IO dictated a minimum die area for the chipset, but the actual controllers driving that IO didn’t need all of that die area. Intel effectively had some free space on its North Bridge die to do whatever it wanted with. In the late 90s Micron saw this problem and contemplating throwing some L3 cache onto its North Bridges. Intel’s solution was to give graphics away for free.

The budget for Intel graphics was always whatever free space remained once all other necessary controllers in the North Bridge were accounted for. As a result, Intel’s integrated graphics was never particularly good. Intel didn’t care about graphics, it just had some free space on a necessary piece of silicon and decided to do something with it. High performance GPUs need lots of transistors, something Intel would never give its graphics architects - they only got the bare minimum. It also didn’t make sense to focus on things like driver optimizations and image quality. Investing in people and infrastructure to support something you’re giving away for free never made a lot of sense.

Intel hired some very passionate graphics engineers, who always petitioned Intel management to give them more die area to work with, but the answer always came back no. Intel was a pure blooded CPU company, and the GPU industry wasn’t interesting enough at the time. Intel’s GPU leadership needed another approach.

A few years ago they got that break. Once again, it had to do with IO demands on chipset die area. Intel’s chipsets were always built on a n-1 or n-2 process. If Intel was building a 45nm CPU, the chipset would be built on 65nm or 90nm. This waterfall effect allowed Intel to help get more mileage out of its older fabs, which made the accountants at Intel quite happy as those $2 - $3B buildings are painfully useless once obsolete. As the PC industry grew, so did shipments of Intel chipsets. Each Intel CPU sold needed at least one other Intel chip built on a previous generation node. Interface widths as well as the number of IOs required on chipsets continued to increase, driving chipset die areas up once again. This time however, the problem wasn’t as easy to deal with as giving the graphics guys more die area to work with. Looking at demand for Intel chipsets, and the increasing die area, it became clear that one of two things had to happen: Intel would either have to build more fabs on older process nodes to keep up with demand, or Intel would have to integrate parts of the chipset into the CPU.

Not wanting to invest in older fab technology, Intel management green-lit the second option: to move the Graphics and Memory Controller Hub onto the CPU die. All that would remain off-die would be a lightweight IO controller for things like SATA and USB. PCIe, the memory controller, and graphics would all move onto the CPU package, and then eventually share the same die with the CPU cores.

Pure economics and an unwillingness to invest in older fabs made the GPU a first class citizen in Intel silicon terms, but Intel management still didn’t have the motivation to dedicate more die area to the GPU. That encouragement would come externally, from Apple.

Looking at the past few years of Apple products, you’ll recognize one common thread: Apple as a company values GPU performance. As a small customer of Intel’s, Apple’s GPU desires didn’t really matter, but as Apple grew, so did its influence within Intel. With every microprocessor generation, Intel talks to its major customers and uses their input to help shape the designs. There’s no sense in building silicon that no one wants to buy, so Intel engages its customers and rolls their feedback into silicon. Apple eventually got to the point where it was buying enough high-margin Intel silicon to influence Intel’s roadmap. That’s how we got Intel’s HD 3000. And that’s how we got here.

Haswell GPU Architecture & Iris Pro
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  • prophet001 - Monday, June 03, 2013 - link

    I have no idea whether or not any of this article is factually accurate.

    However, the first page was a treat to read. Very well written.

    :)
    Reply
  • Teemo2013 - Monday, June 03, 2013 - link

    Great success by Intel.
    4600 is near GT630 and HD4650 (much better than 6450 which sells for $15 at newegg)
    5200 is better than GT640 and HD 6670 (currently sells like $50 at newegg)
    Intel's intergrated used to be worthless comparing with discret cards. It slowly catches up during the past 3 years, and now 5200 is beating a $50 card. Can't wait for next year!
    Hopefully this will finally push AMD and Nvidia to come up with meaningful upgrade to their low level product lines.
    Reply
  • Cloakstar - Monday, June 03, 2013 - link

    A quick check for my own sanity:
    Did you configure the A10-5800K with 4 sticks of RAM in bank+channel interleave mode, or did you leave it memory bandwidth starved with 2 sticks or locked in bank interleave mode?

    The numbers look about right for 2 sticks, and if that is the case, it would leave Trinity at about 60% of its actual graphics performance.

    I find it hard to believe that the 5800K is about a quarter the performace per watt of the 4950HQ in graphics, even with the massive, server-crushing cache.
    Reply
  • andrerocha - Monday, June 03, 2013 - link

    is this new cpu faster than the 4770k? it sure cost more? Reply
  • zodiacfml - Monday, June 03, 2013 - link

    impressive but one has to take advantage of the compute/quick sync performance to justify the increase in price over the HD 4600 Reply
  • ickibar1234 - Tuesday, June 04, 2013 - link

    Well, my Asus G50VT laptop is officially obsolete! A Nvidia 512MB GDDR3 9800gs is completely pwned by this integrated GPU, and, the CPU is about 50-65% faster clock for clock to the last generation Core 2 Duo Penryn chips. Sure, my X9100 can overclock stably to 3.5GHZ but this one can get close even if all cores are fully taxed.

    Can't wait to see what the Broadwell die shrink brings, maybe a 6-core with Iris or a higher clocked 4-core?

    I too see that dual core versions of mobile Haswell with this integrated GPU would be beneficial. Could go into small 4.5 pounds laptops.

    AMD.....WTH are you going to do.
    Reply
  • zodiacfml - Tuesday, June 04, 2013 - link

    AMD has to create a Crystalwell of their own. I never thought Intel could beat them to it since their integrated GPUs always has needed bandwidth ever since. Reply
  • Spunjji - Tuesday, June 04, 2013 - link

    They also need to find a way past their manufacturing process disadvantage, which may not be possible at all. We're comparing 22nm Apples to 32/28nm Pears here; it's a relevant comparison because those are the realities of the marketplace, but it's worth bearing in mind when comparing architecture efficiencies. Reply
  • Death666Angel - Tuesday, June 04, 2013 - link

    "What Intel hopes however is that the power savings by going to a single 47W part will win over OEMs in the long run, after all, we are talking about notebooks here."
    This plus simpler board designs and fewer voltage regulators and less space used.
    And I agree, I want this in a K-SKU.
    Reply
  • Death666Angel - Tuesday, June 04, 2013 - link

    And doesn't MacOS support Optimus?
    RE: "In our 15-inch MacBook Pro with Retina Display review we found that simply having the discrete GPU enabled could reduce web browsing battery life by ~25%."
    Reply

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