Minecraft wiki entry for End_spike, associated text: A 3-block radius pillar ending at y=76 (total of 1596 blocks of obsidian);
A 3-block radius pillar with iron bars ending at y=79 (total of 1659 blocks of obsidian);
A 3-block radius pillar with iron bars ending at y=82 (total of 1722 blocks of obsidian);
A 4-block radius pillar ending at y=85 (total of 3145 blocks of obsidian);
A 4-block radius pillar ending at y=88 (total of 3256 blocks of obsidian);
A 4-block radius pillar ending at y=91 (total of 3367 blocks of obsidian);
A 5-block radius pillar ending at y=94 (total of 5358 blocks of obsidian);
A 5-block radius pillar ending at y=97 (total of 5529 blocks of obsidian);
A 5-block radius pillar ending at y=100 (total of 5700 blocks of obsidian);
A 6-block radius pillar ending at y=103 (total of 9167 blocks of obsidian).