![]() | |||||||||||
Messages in this thread Complete thread (EXPERIMENTAL) |
Rick Jones wrote:
Into which slot was the Neptune inserted? (sure will be nice to have Alex Chiang's pci slot id patch in mainline one of these days :) Is that slot x4, x8, x16? I can find out excactly .. on monday. But shouldn't x4 be enough anyway? wikipedia says 250MB/s pr. lane. And no slots is less than x4, so I thought that it didn't matter to me. No you need 8x for 10-GigE. The 250 MB/sec per lane is 2 Gbps per lane so 4x is only 8 Gbps. For a typical PCI-E transaction size of 128 bytes, and PCI-E protocol overhead of 20 to 24 bytes, that takes off about 20%, which leaves you with about 6.5 Gbps of usable bandwidth, which is further reduced somewhat by the required PCI-E ACK and flow control packets that accompany the actual data transaction packets. I am not an expert on PCI-E but I believe this info to be generally correct. -Bill | ||||||||||
![]() | |||||||||||
| Last update: 2008-05-10 04:23 [W:0.274 / U:0.060 seconds] ©2003-2005 Jasper Spaans | |||||||||||