Motherboard: Difference between revisions

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Hi I am new here. I am sorry if "/index.php?title=Motherboard&action=edit"
(This page is riddled with speculation and extrapolation of information from dodgy sources, so take it with a grain of salt.)
is not the right place for this post. My name is Ned
 
I am from  Uruguay
The Xbox 360 motherboard (or motherboard) has undergone a few revisions, as Microsoft has corrected mistakes or added/improved existing features.
 
*Known revisions include:
:*[[Xenon_(Motherboard)|Xenon]] (Launch hardware)
:*[[Zephyr]] (Elite)
:*[[Falcon]] (65nm Chipset revision)
:*[[Opus]]
:*[[Jasper]] (Onboard Memory_Unit)
 
== Details ==
The motherboard PCB has four layers (sources: [http://www.ccw.com.cn/notebook/pczx/sy/htm2005/20051028_16OMI.htm], [http://www.anandtech.com/video/showdoc.aspx?i=2414]), implying that the top and bottom layers (the ones we can see and probe) contain most of the signals. This is a good thing :)
 
 
== CPU, GPU, & Front side bus ==
According to [http://www.ccw.com.cn/notebook/pczx/sy/htm2005/20051028_16OMI.htm these] [http://www.cdrinfo.com/images/uploaded/Xbox_Architecture_large.gif three] [http://en.wikipedia.org/wiki/Xbox_360#Hardware_specifications sources] the FSB is a serial bus with 16 differential pairs in each direction, and each pair runs at 5.4Gbit/s. This agrees with Microsoft's published bandwidth specification of 21.6 Gbyte/sec (10.8 Gbyte/sec each way, 16 bits/2 bytes at a time, 5.4 Gbit/sec per pair).
 
Looking at photos of the motherboard, we can see 40 pairs of carefully routed tracks between the CPU and GPU. 32 pairs (16 each way) + 8 clock/handshake/parity? pairs = 40 pairs.  
 
This very high frequency interface will make probing and snooping on the bus extremely difficult, which is unfortunate because the Xbox1 security was compromised in part by a FSB bus snoop done by bunnie. At this frequency, the (relatively) simple task of attaching probe wires to the FSB will change the impedance seen on the bus by the FSB PHYs and cause the bus to fail to work correctly (look at eye diagram...). It might still be possible to probe the FSB with very expensive gear though.
 
It's not very likely that they made the mistake of sending sensitive information on an exposed bus again though.
 
 
== Photos ==
*http://arstechnica.com/articles/paedia/cpu/xbox360-1.ars
*http://g-prime.net/x360/open/
*http://www.darkmoon.org/xbox360_photos.htm
[[Category:Hardware]]

Revision as of 06:01, 18 August 2010

Hi I am new here. I am sorry if "/index.php?title=Motherboard&action=edit" is not the right place for this post. My name is Ned I am from Uruguay