No, pre-production and sandbox environments are not the same.
They serve different purposes in the software development and deployment lifecycle. Pre-Production environment is the only system environment where we have to do Performance Testings like Stress Testing and Load Testing etc. & UAT, but In some companies where Pre-Production environment is not available, then They do few rounds of Performance Testing in QA Environment itself or they do Performance Testing slightly for few Major scenarios/ Priority 1 scenarios or Priority 1 business functions Testing.