[CentOS] Measuring memory bandwidth utilization

I'd like to know what the cause of a particular DB server's slowdown might be. We've ruled out IOPs for the disks (~ 20%) and raw CPU load (top shows perhaps 1/2 of cores busy, but the system slows to a crawl.

We're suspecting that we're simply running out of memory bandwidth but have no way to confirm this suspicion. Is there a way to test for this? Think: iostat but for memory bandwidth instead of disk IO.

So far, searching has found intel-cmt-cat-master which isn't supported on our CPU and oprofile which *sounds* like it does what I want from their website but I can't seem to get output that, in any way, tells me what the bandwidth usage is.

Any idea?