Broadwell's EDRAM: VCache Before VCache Was Cool

EDRAM was very different, and IBM still uses it today. It is DRAM that is on the same die as the cores, which makes it far slower than AMD&#x27;s VCache (which is SRAM). The concept is the same - putting a huge amount of cache on chip - but it&#x27;s a very different solution.<p>The Intel solution was also not 3D stacked. It&#x27;s a little like having an HBM stack next to the chip as a cache.

It was, at least, pretty good for video gaming: <a href="https:&#x2F;&#x2F;web.archive.org&#x2F;web&#x2F;20181025222235&#x2F;https:&#x2F;&#x2F;techreport.com&#x2F;review&#x2F;34205&#x2F;checking-in-on-intel-core-i7-5775c-for-gaming-in-2018" rel="nofollow">https:&#x2F;&#x2F;web.archive.org&#x2F;web&#x2F;20181025222235&#x2F;https:&#x2F;&#x2F;techrepor...</a> though, alas, it doesn&#x27;t look like the Wayback Machine properly sucked up the whole article before the site got sold to particularly nasty link&#x2F;content farmers.<p>(I miss Tech Report.)

My previous laptop I bought in 2016 had an Intel Skylake processor with 64MB eDRAM. Specifically, it was based on Intel Core i3-6157U: <a href="https:&#x2F;&#x2F;ark.intel.com&#x2F;content&#x2F;www&#x2F;us&#x2F;en&#x2F;ark&#x2F;products&#x2F;96484&#x2F;intel-core-i3-6157u-processor-3m-cache-2-40-ghz.html" rel="nofollow">https:&#x2F;&#x2F;ark.intel.com&#x2F;content&#x2F;www&#x2F;us&#x2F;en&#x2F;ark&#x2F;products&#x2F;96484&#x2F;i...</a> The laptop used DDR3L memory, I installed 16GB there. Was pretty fast despite small, light, and only 2 CPU cores.<p>I think the main reason chips like that didn’t took off was marketing. Laptop OEMs tell consumers that if they want performant graphics they must buy laptops with discrete GPUs despite expensive, heavy, and discharge batteries faster.

&quot;But I wonder if Intel could pull off high capacity caching sometime in the future&quot;<p>The Xeon Max processors had up to 64GB of HBM that could act as memory or shadow external memory effectively acting like a huge L4 cache.<p>No Xeon 6 seems to have that feature, at least not for now. Xeon 6&#x27;s top out at a paltry 504MBs of L3.