Well the RAM is irrelevant - at the end tit runs down on developer competence (https://use-the-index-luke.com/) and IO performance. Know what you do not talk about? IO PERFORMANCE. Like "all Super Fast SSD setup".
CPU good enough? WHO KNOWS. You should - you can easily measure CPU utilization, but even if that is 100% - it means nothing because it could also mean someone with less knowledge than a used car salesman has about SQL has writte nextremely bad and performance killing (CPU intensive) queries. Been there, seen that.
Also, what is too slow - HOW MANY QUERIES IN PARALLEL? An E5 2667 is nice. It is still a low end processor. Even with efficient queries, and super fast IO, there is a limit how much you can throw on a low end server and expect it to perform. DO YOUR JOB - measure, estimate. Do not expect us to help you without any idea what you talk about. Maybe you can optimize the queries - and STILL need 128 cores, no 8. WHO KNOWS EXCEPT YOU?