* |
VMEbus (VME64x) |
VXS |
ATCA |
uTCA |
crates based on no standard |
PC based systems |
Number of slots per 19” crate |
21 |
21 |
14 |
12 |
|
|
Max. power per slot |
|
|
400 |
80 |
|
|
Max. data transfer bandwidth |
~50 MB/s |
16 differential pairs per payload slot. Allows e.g. for two x4 PCIe ports |
|
|
|
Many GB/s (depends on PCIe card) |
Cooling (air flow) |
vertical |
vertical |
horizontal (vertical possible) |
horizontal (vertical possible) |
|
horizontal |
Space for connectors |
front and back |
front and back |
front and back |
front and back (only MTCA.4) |
|
only back |
Card dimensions |
(6U x 160 mm or 9U x 340 mm) x 20.3 mm |
(6U x 160 mm or 9U x 340 mm) x 20.3 mm |
8U x 280 mm x 30.48 mm |
(74 or 149 mm) x 180 mm x (13, 18 or 28 mm) |
|
|
RTM dimensions |
|
|
8U x 60 mm x 30.48 mm |
(74 or 149 mm) x 180 mm x (13, 18 or 28 mm) |
|
|
Standard published in |
1997 (based on VMEbue from 1982) |
2006 (based on VMEbus from 1982) |
2001 |
2006 |
|
|
System monitoring |
Not defined. Slaces can be monitored via the bus in a user defined way |
IPMI / I2C possible (but not mandatory) |
IPMI / I2C |
IPMI / I2C |
|
IPMI possible at the PC level. Card level not defined |
Redundancy |
Not defined |
Backplane supports redundant start architecture |
Full support at H/W level (PSUs, cooling units, shelf meneger). Redundancy at the level of blades may require special S/W |
Same as for ATCA |
|
Not defined. Redundant PSUs possible |
Volume of the global market |
claimed to be ~1 Billion USD |
Very small |
unknown |
unknown |
|
Very large |
Type of power supply |
230 VAC in or next to crate |
230 VAC in or next to crate |
External 230VAC to -48 VDC converter |
External 230VAC to -48 VDC converter or local 230 VAC |
|
230VAC PSU in PC chassis |
Hot swap of I/O cards |
Possible but rarely used |
Possible but rarely used (S/W issue) |
Possible (user S/W has to support it) |
Possible (user S/W has to support it) |
|
Not possible |
Mezzanines on main board |
PMC & XMC |
PMC & XMC |
AMC |
FMC possible |
|
User deinfed |
Used also by (CERN only) |
CERN accellerator controls |
COMPASS, BE/CO (just the mechanics) |
LHCb (planned) |
CMS |
LHCb (may be replaced by ATCA) |
CMS |
Reuse of existing H/W infrastructure (crates, I/O cards) |
Possible |
Possible (new backplanes required; maybe also new PSU) |
not possible |
not possible |
not possible |
not possible |
Communication protocol |
VMEbus |
VMEbus & (Infiniband, SRIO, PCIe, Eth) |
Infiniband, SRIO, PCIe, Eth (and user defined protocols) |
Infiniband, SRIO, PCIe, Eth (and user defined protocols) |
|
PCIe (within the PC) Infiniband,ethernet,etc between PCs |