CIR and CBS?

Hi,

I'm trying to setup bandwidth limitations for each port on a Cisco SG500X-24 switch. Each port needs to be locked down to 128MB up and down. Under QOS -> Bandwidth it's asking for CIR in Kbytes (which i set to 128000) and CBS in bytes (which I set to 2500000 based on googling some information about CIR/CBS).

Is this correct for a 128MB speed/bandwidth limit? If not, how do I get the correct numbers? I'm getting some weird traffic issues with those numbers, i.e. slow page loads, etc. If I turn the limitations off, pages load like normal. Any help would greatly be appreciated.

Thanks!