9 ms·
Out of curiosity, how long are these paths generally?
by foota 3y ago
Out of curiosity, how long are these paths generally?
- jiggawatts 3y agoLow single digit millimeters for current chip designs. One reason that clock speeds are going above 5 GHz these days is that chips are getting smaller. That means shorter signal propagation distances.
- tux3 3y agoSo, when I talked about the length of the path in number of transistors, I oversimplified a bit. The length of the path would be measured in nanoseconds (or even picoseconds). That number depends not just on the number of transistors, but also on the routing delay (are the interconnect wires between transistors long or short? How high is the resistance/capacitance?), and a lot of low-level details of the fabrication process that are extremely not public But say you buy a brand new CPU and it's clocked at 5 GHz, you can easily get a rough estimate of how long the critical path is, since 1/5GHz = 0.2ns What you can't easily get is the speed of the transistors or the number of transistors in the critical path, that info is not public, and you could only make a very rough guesstimate.