At a breakneck pace and At a breakneck speed

At a breakneck speed and at a breakneck pace are semantically related. In some cases you can use "At a breakneck speed" instead an adverb phrase "At a breakneck pace".

At a breakneck pace and at a breakneck speed are semantically related. You can use "At a breakneck pace" instead an adverb phrase "At a breakneck speed".