Second generation Broadcom
D-Link keeps making it more difficult to open the chassis of its routers, and this DIR-868L is no exception. For opening up products that we're testing (and have to send back to the manufacturer) we usually push them until we get worried about the structural integrity and causing irreversible damage. In this case, it meant we had to stop before we managed to open the router at all.
Nevertheless, we do know what components D-Link used for the DIR-868L. All chips come from Broadcom, and they're the same as in the Linksys EA6700. A dual-core BCM4708 serves as CPU and switch. Its two Cortex-A9 cores are clocked at 1 GHz. The 2.4 GHz band is provided by the BCM4331, a chip used in many other routers and capable of three data streams. The 5GHz band (802.11ac) comes from the BCM4360.
The PCB takes up the entire vertical length of the router, so the antennas had to be positioned differently than in the DIR-645. They're all separate antennas, some of which are metal and others a type of metamaterial.
USB 3.0 on routers still benefits marketing more than it does transfer rates. Only the Netgear Centria was fast enough for USB 3.0 to have any added value. The D-Link DIR-868L is not, however. We connected a USB 3.0 external hard disk, and the read speed fell just short of 18 MB/s, with a writing speed of 14.5 MB/s. Not very impressive, and definitely not fast enough to make this router combined with a hard disk into a poor man's NAS device. It's fine for transferring and sharing a few files, but you don't have to transfer large amount of data with this setup.