Serial communication the parallel bus's advantage of simplicity (no need for serializer and deserializer, or SerDes) and to outstrip its disadvantages (clock skew, interconnect density). The migration from PCI to PCI Express is an example. Many serial communication systems were originally designed to transfer data over relatively large distances through some sort of data cable. Practically all long-distance communication transmits data one bit at a time, rather than in parallel, because it reduces the cost of the cable. The cables that carry this data (other than "the" serial cable) and the computer ports they plug into are usually referred to with a
Embarrassingly parallel are thus well suited to large, Internet-based distributed platforms such as BOINC, and do not suffer from parallel slowdown. The opposite of embarrassingly parallel problems are inherently serial problems, which cannot be parallelized at all. A common example of an embarrassingly parallel problem is 3D video rendering handled by a graphics processing unit, where each frame (forward method) or pixel (ray tracing method) can be handled with no interdependency. Password cracking is another embarrassingly parallel task that is easily distributed on central processing units, CPU cores, or clusters. "Embarrassingly" is used here in the same sense as in the phrase