Whats the difference between 8xx opterons and 2xx?

[Maximilian]

Reason im asking is i got a pair of 842's for cheaper than the equivilent pair of 242's so i wondered why these 842's work in 8 way servers and the 242's dont?

 

[aka1nas]

8xx Opterons have an extra functioning coherent Hyper Transport link that 2xx don't have enabled.

IIRC it goes like this:

1xx has 1 HT link (for RAM)
2xx has 2 HT links (1 for RAM, 1 for the 2 cpu's to talk to each other)
8xx has 3 HT links (1 for RAM, 2 links to talk to other CPUs. CPU's have to communicate through others depending on the number of CPUs and design of the motherboard)

 

[Maximilian]

Originally posted by: aka1nas
8xx Opterons have an extra functioning coherent Hyper Transport link that 2xx don't have enabled.

IIRC it goes like this:

1xx has 1 HT link (for RAM)
2xx has 2 HT links (1 for RAM, 1 for the 2 cpu's to talk to each other)
8xx has 3 HT links (1 for RAM, 2 links to talk to other CPUs. CPU's have to communicate through others depending on the number of CPUs and design of the motherboard)

Thanks for the input :thumbsup: Ill sleep soundly knowing i got 1 extra HT link for cheaper, as useless as it is to me