Skew is the difference in arrival times between signals in a group. However, this has a disadvantage for traditional parallel links: skew. So it's now possible to have much higher bitrates. The devices have also got faster with better signal processing. So as the devices get smaller there's pressure for smaller interfaces with fewer cables. Look at how large things like Centronics printer cables and 40-pin SCSI cables were! You're not going to see a phone with a Centronics connector on. There are two factors involved, skew and size.Īdding more connectors makes both the cable, its connectors and the receptacles on each device larger and more expensive.
![serial vs parallel printer connection serial vs parallel printer connection](https://www.gs-possystem.com/Content/upload/201747587/201710141844116173072.jpg)
Such as PCIe, where a card may have 1x to 16x "lanes".
Serial vs parallel printer connection serial#
The shift is from "parallel on a single clock" to "multiple serial links". And remains easier to transmit and extract even if the serial stream is per bit lane 16, 32, 64, or more times faster than the parallel. SATA is the serial version of PATA which is a direct decendent to IDE, not that serial was faster just that it is far easier to sync up with and extract a serial stream than it is to keep N parallel bits in sync from one end to the next. Still uses serial lanes with the data load balanced an rejoined, the speeds increase each generation per serial interface rather than adding more and more serial pairs. Pcie likewise, started with one or more serial interfaces with the data load balanced. That marginal cost in server farms was enough to abandon the traditional path for industry standards and go off and whip one up on the side and roll it out in a hurry. Costing half-ish the copper or fiber in the cables and elsewhere. Recently there is a movement from instead of moving up from 10 gig ethernet to 40 gig using 4 × 10 gig lanes, to 25 gig per lane so one 25 gig pair or two 25 gig pairs to get 50 gig rather than four 10 gig pairs. Then there is the real estate from pins to pcboard to connectors. You can easily run N times faster using one serial interface. The key is with speed, routing, cables, connectors, etc keeping the bits parallel and meeting setup and hold times at the far end is the problem. Obviously one serial interface can go no faster than one bit lane of a parallel bus all other things held constant. Each of these lanes is an independent serial interface taking advantage of the "serial speed", but the overall transmission of data is split up load balanced down the separate serial interfaces, then combined as needed on the other side. Interestingly we now have parallel serial buses, your pcie, your ethernet (okay if you run 40GigE is 4 × 10 gig lanes 100Gig is 10 × 10 gig or the new thing coming is 4 × 25 gig lanes). Yes, absolutely that one serial interface has to run N times faster than an N wide parallel bus in order to be "faster" but a long time ago now we reached that point.
![serial vs parallel printer connection serial vs parallel printer connection](https://i.stack.imgur.com/7LxrP.jpg)
![serial vs parallel printer connection serial vs parallel printer connection](https://support.brother.com/g/b/img/faqend/faqp00001536_000/hk/en/25962/PtouchTemplateSetting.gif)
You can help by creating lots of transitions, 8b/10b, bi-phase or manchester encoding, there are lots of schemes (yes this means you are adding even more bits). With serial "all you have to do", is be able to is extract the clock and as a result the data. The problem is keeping the signals on a parallel bus clean and in sync at the target.