The Boeing avionics you describe relate to the 767/757 and 737-300/400/500. The EFIS CRTs display video data generated by the symbol generators. 757 and 767 EICAS CRTs are driven by an EICAS computer which also acts as a symbol generator.
The 747-400 uses three EIUs (EFIS/EICAS Interface Unit) to supply the six CRT or LCD
Display Units with digital data for processing and display. The terms EADI and EHSI are replaced by PFD and ND, as per Airbus terminology. The DUs generate the graphics displayed from the digital data received. The Boeing EIU is analagous to the Airbus DMC, except it receives data direct from the aircraft systems, not via the data concentrators (as with Airbus).
On the 777 and 767-400 the six DUs are fed with data from three DPCs (Display Processing Computers).
The 737 NG
has two DEUs (Display Electronic Units) which distribute data to the six DUs.
Boeing does not have a separate equivalent to the Airbus FWC and SDAC. These computers collect the engines and systems data to be displayed on ECAM (data for red warning data direct to the FWC, amber caution and engine parameter data via the SDAC and FWC). It is then sent to the DMCs. Other aircraft data, such as Nav and autoflight information, goes directly to the DMCs. The DMCs generate the images to be displayed on the various DUs.
The FWC also generates all the aural alerts and controls the overhead panel pushbutton captions.
The glass isn't half empty, or half full, it's twice as big as it needs to be.