Linode CPU stats on cacti
I might try running a single CPU-bound thread for awhile (~30 minutes or so), spinning one CPU at ~100%… throwing a big, constant load at both graphs simultaneously should establish what sort of error it is.
Just out of curiosity, which kernel/version are you running? Ultimately, the number cacti is reporting comes from the kernel, so perhaps there's a known (or at least reproducible) difference between that kernel version and whatever the hypervisor-dowsing expedition feeds Linode's graphs.
I used a different 4 core template (Host MIB) and now it matches linodes.
Care to share your results so if someone else has the same problem in the future?