而 TTD 與 rr 兩者最大的差異當然是平台支援的情況：
The most important and obvious difference between TTD and rr is that TTD is for Windows and rr is for Linux (though a few crazy people have had success debugging Windows applications in Wine under rr).
但另外一個也很重要的差異是 TTD 支援完整的 multi-threading，這對於現代的程式來說還蠻常見的：
TTD supports recording of multiple threads in parallel, while rr is limited to a single core.
On the other hand, per-thread recording overhead seems to be much higher in TTD than in rr. It's hard to make a direct comparison, but a simple "start Firefox, display mozilla.org, shut down" test run on similar hardware takes about 250 seconds under TTD and 26 seconds under rr.