What's inside a server ?

[OAudio]

I have working with some c621 board schematics and fab files for a project where I would like to understand the routing of some traces across a motherboard. If you have ever wondered what fiendish complexity sits inside the motherboard of the PC that's generating your music (probably lost at least 95+% of people with that sentence   ) take a look.

 

 

 

Above ~3600 traces fanned out from LGA3647 CPU sockets, to memory / DMI / PCIe Lanes and chipset etc. 8 layers are needed for the fan out, most of the traces are just 0.15mm. Just staggering design ! 

 

 

 

Above fan out from a c621 chipset, quite a feat as well, something like 2000+ traces here too !

 

If anyone has any images showing the hidden beauty / prowess of the people that design our computing platforms do put them up.

 

Regards,

 

OAudio.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

[ASRMichael]

Just goes to show the complexity of digital music!
 

In your view would an increase in size of traces result in increase in sound quality? Say 1mm. I appreciate hypothetical, because the board would be huge. After all many have seen increase in SQ from thicker gauge wires, so why wouldn’t it?

 

Maybe that’s the key to fully unlocking the potential of digital! 

[OAudio]

Yes mind blowing, makes you wonder how on earth it can all work out as it does when listening to music  

 

Regarding the trace size, the physical geometry its critical, but larger would not really help. Most of the lines between say a CPU and other systems such as memory another CPU or PCie for example run at muti Gb/s serial speeds. Even over very short board distances they have to be impedance matched to manage insertion loss and reflections otherwise signal integrity is not good enough for reliable transmission.

 

The physical geometry of a  traces dimensions are the way this matching is done. The width of the trace, thickness of the copper the separation of the + - trace lines and in the case of differential pairs, how far +- lines they are apart and the distance to the nearest reference ground layer are the main parameters that get juggled. Even the dielectric constant of the PCB board material really matters in matching the source and termination ends of all the pairs of traces.

 

Some links for instance between CPU and memory also need to be length matched so that the transmission time across these lines doesn't end up introducing phase skew in the signals as they arrive at the device across different trace pairs. 

 

The lengths the designers go to to lay this stuff out really shows when you look at the production file layers. 

 

There is so much that has to be thought about and then debugged, you really have to respect the guys that do this stuff !