performance of multi-port network adapters. (pci-e)

[TechBoyJK]

I have 3 servers, and I need to add 2 gigE nics to each one. Each server has 2 available PCI-E ports. I was thinking about putting a single port NIC in each pci-e port. However, it seems it's slightly less expensive to buy dual-port cards. It will cost about $65 to get 2 single port Intel Pro/1000 nics. I can get a dual-port Intel Pro/1000 for about $50. It'd save money, and I'd leave a pci-e slot open for another card if I need it.

Question, is there any noticeable performance hit by putting two+ ports on one card, if it's PCI-E?

2 of these?

http://www.amazon.com/Intel-Gigabit-...tel+pro%2F1000

1 of these?

http://www.amazon.com/Intel-1000-Dua.../dp/B000BMZHX2

Thoughts?

 

[azazel1024]

I run a crap load of the Gigabit CT single port cards in my machines and they work great. The dual port cards should also work well. It probably doesn't matter to you, but IIRC during my research, the Intel Pro/1000 card is going to use around 5w or so compared to 1.9w for each Gigabit CT, so the overall power consumption will be a hair higher.

As for performance, no, they'll both be able to do 1Gbps full duplex, you'll just be eating a 4/8/16x PCI-e slot with the dual port card as opposed to a pair of 1x PCI-e slots with the Gigabit CT cards.

IIRC both cards are PCI-e 1.0a, so you are looking at 250MB/sec on a 1x link, so a PCI-e 1x port will just be able to handle a single port card at full duplex speeds. A dual or quad port card will require 4x PCI-e to handle 2/4 ports.

Part of what annoys me about Intel, they make awesome cards, but they are VERY slow to update them. Only some of their newest of the newest networking cards are PCI-e 2.0 and no PCI-e 3.0 cards yet...the later of which would allow a quad port cards on a PCI-e 1x slot, full speed and the former would at least allow dual port cards on a 1x slot.