After the widely covered DDoS attack on WordPress.com hosted blogs and Automattic’s efforts to thwart it; Matt Mullenweg in email to customers (and blog post), reveals the computing power behind WP.com’s infrastructure, “for WP.com we’re now at 8,921 CPU cores across 2,475 physical processors, 8,200 gigabytes of memory (RAM).”
He continues, “We’ve changed how we’ve done storage, but now that layer includes on its own 1.3 terabytes of RAM, 1.3 petabytes of storage, and 8.9 terabytes of solid state disks. (Plus Amazon S3, which we use as backup to our internal systems.) Also, we’re adding new servers constantly. :)”