mcuWeb Video Confering performance

We have implements an video conferencing System by using Asterisk + mcuWeb, currently mcuWeb run on an PC with 8-core CPU, 32G Ram, however it still can't handle over 16 concurrent user in a meeting room under 720P resolution, In order to increase it's performance we try to setup hardware h.264 encoder/decoder on PC instead of using mcuWeb software encoder/decoder, but we can not find this kind of devices, is anyone has any information about h.264 hardware encoder/decoder? or other suggestion on improve webMCU performance?

Thanks.