The PW 815GA used on the Gulfstream G600 has a 965°C (1,769°F) ITT limit, with a 20 second 1000ºC limit
The bypass ratio, fan to core, is about 5.5 to 1 (by memory so if I'm incorrect, don't hang me) and I think the turbine temp is measured somewhere a bit lower in temp than the turbine inlet temp. Interstage turbine temp or ITT.
Also of note, the relatively high bypass (for a corporate jet engine) ratio results in a slight lack of high speed and high altitude performance when compared to the older Rolls Royce designs. The RR engines have about a 4 to 1 bypass ratio and fewer low pressure turbine stages. Resulting in much more heat out the back, and higher discharge velocity (better speed at altitude).
The Pratt powered Gulfstream jets have phenomenal takeoff and climb performance, with Mach 0.87 to 0.90 climb speeds. But performance trails off a bit by FL470 and is dead by FL510.
TLDR:
2 different philosophies.
The RR BR710/725 are older, well honed designs. Mach 0.92 at FL490 is possible
The PW 815 GA uses smaller core, higher bypass, and runs harder. Mach 0.88 at FL490 is barely possible. Uses more fuel.
Pratt Whitney, Newer higher bypass, less efficient... :
Rolls Royce BR725 More conventional, lower bypass, faster, more efficient:
