Quote Originally Posted by gOJDO
@Lightman
FX-7x is different from Opteron. It has unbuffered ODMC and unlocked multiplier.
Also there are sAM2 X2 with 2x1MB L2: 4000+, 4400+, 4800+, 5200+.
Right! But differences between Opteron and FX-7x are made after die is finished by cutting small bridges or connecting different pads from core to BGA.
There is also theory why FX-7x have only 2 DIMMs per socket. According to some people (I forgot who and when ) Opteron can work with unregistered 2 DIMMs, but anything more will put to much pressure on Drive Strength of memory controller. The reason why it's working on S939 and AM2 is that pins used for extra HT links in Opterons are used to add Drive Strength (more power/load can by applied). It was exactly same with old AMD760MP chipset. It was able to work with 2 unregisterd DIMMs or 4 registered. (on side note someone on this forum was claiming running unregistered memory with FX-51 on S940)

Regarding sAM2 X2 with 1MB L2 they all are discontinued, so of no importance. But we will get 1MBL2 once again with X2 6000+.