patternContentUnits

html,
body,
svg {
  height: 100%;
}

html

<svg viewBox="0 0 200 100" xmlns="http://www.w3.org/2000/svg">
  <!--
  A pattern tile that content coordinates and values are
  computed against the current coordinate user space.
  Note that the size of the tile is computed against
  the bounding box of the target element
  -->
  <pattern
    id="p1"
    width="20%"
    height="20%"
    patternContentUnits="userSpaceOnUse">
    <circle cx="10" cy="10" r="10" />
  </pattern>

  <!--
  A pattern tile that content coordinates and values are
  computed against the bounding box of the target element.
  Note that the size of the tile is also computed against
  the bounding box of the target element
  -->
  <pattern
    id="p2"
    width="20%"
    height="20%"
    patternContentUnits="objectBoundingBox">
    <circle cx=".1" cy=".1" r=".1" />
  </pattern>

  <!-- Left square with user space tiles -->
  <rect x="10" y="10" width="80" height="80" fill="url(#p1)" />

  <!-- Right square with bounding box tiles -->
  <rect x="110" y="10" width="80" height="80" fill="url(#p2)" />
</svg>