This is a good lesson in resource-planning and making hardware decisions across CPU lines and generations. I've had the unique experience of needing high-end CPUs for applications in a few different industries, but also the luxury of being able to test and benchmark before major architecture changes.
As a result of this, my rule is to examine the product lines and move to processors that have comparable positions in the portfolio when you make hardware changes.
What's better? A 2010 Mercedes S-Class or a 2014 Mercedes C-Class? It depends...
- The Intel Westmere x5690 was a 3.47GHz hex-core processor. It was Intel's top-end mainstream server CPU during its product lifetime.
- The Intel Westmere-EX E7-4807 was a 1.86GHz hex-core processor meant for quad-socket boards. This CPU was at the bottom of the product line. It was released in the same quarter as the x5690.
Intel Comparison Chart - Comparing the x5690 and E7-4807
So what's wrong?
Your "new" server is also running an older architecture. Remember, the bigger server platforms (quad-socket, etc.) don't rev as often as the smaller systems. You have a CPU that's running around half the clock speed of the previous CPU, but of the same generation, thus the performance drop. The E7-4807 is also missing Turbo Boost.
I'd be interested to know what prompted the upgrade. You likely had the raw CPU performance you needed. Was it memory or another factor? What was the bottleneck?
A better move if you simply needed additional cores would have been a newer dual-socket system, but with top-line Intel E5-2643v2 (3.5GHz) or E5-2697v2 (2.9GHz) CPUs.