Review on Tech 1067MHz 1066MHz MacPro4 Memory by Michael Caste

Memory works fine. However, that 8GB of memory doesn't seem to be compatible with other types of memory. In addition, I installed another 16 GB of mixed memory (4 x 2 GB cards and 2 x 4 GB cards). My Mac Pro 4.1 (Early 2009) wouldn't start (complained about bad RAM) until I pulled out all but the new 32GB (4 x 8GB boards). After that, the system boots up normally and works perfectly. The catalog says 16GB boards can't run on less memory, but apparently the same can be said for 8GB boards.