Straight 'Desktop' not LLD.
as far as MTRR I have this CONFIG_MTRR=y
but after that
# CONFIG_MTRR_SANITIZER is not set
# CONFIG_X86_PAT is not set
# CONFIG_EFI is not set
another nice option is to set the tick rate at 1000Hz.
as far as RCU...
You shouldn't need DMA Remapping but test it out.
CFQ for IO Schedueler.