When we measured the different memory managers during the Delphi memory manager challenge we had a different conclusion, at least compared to the newer per thread allocators like scalemm, smartmm and topmm and family. It may be that a FPC conversion is possible for those. The most important think conclusion was that the Delphi MM (FastMM) and cmem do not scale.
In some applications cmem indeed outperforms the fpc default a memory manager, but it depends on application as I explained.
The benchmark sourcecode (for 32 bit) can be optained from
http://fastcode.sourceforge.net/. My old collegue Andre Musche has likely a 64 bit version of SmartMMv2 as well. I will ask him.
(Lock-free context switching) My other former collegue Ivo Tops wrote topmm.
I can prepare those (smartmmv2 and topmm) for fpc - windows32/64 (did that before, but code is not current: fpc 2.0.)
[to be completed with example]