In our testing the real world performance is within 10% of each other for the entry level <$100 NICs from both vendors.
CPU utilisation wise is in the order of ~1-2% difference max (because the difference is so little it is in the margin of error and cannot be conluded)
We have deployed systems running sustained throughput of 200Mbps on a Realtek 8168 NIC (the most common chip of the PCI-E cards) without problems.
The trick is to stay under 30% network utilisation if your NIC is not the most crash hot on the market (i.e. <300Mbps on a Gigabit NIC)
If it's on the motherboard and you have an Intel NIC and it's a small VMS you may be paying too much for the motherboard, IMO. Realtek can be perfectly reasonable in normal enterprise use. Have not seen streaming issues with specific ethernet hardware but I do think that is a good question.
If you're buying an add-on card Intel is likely much more expensive and not clearly worth the difference.
Yeah, if you were sending 200 H.264 1080P streams to one VMS, I'd want high end ethernet hardware and therefore maybe Intel.
IPVMU Certified | 01/23/14 03:56am
Hello. There is no comparison! Go with the Intel NIC. In my testing, I got 10x throughput using an Intel card versus the onboard (motherboard based) Realtek NIC. This testing was on a NAS, not video surveillance related, but the difference was dramatic. I was copying gigabyte files (so not really comparible to video surveillance file sizes), and they were going to slowly, it was like watching paint dry. When I put in an Intel NIC, my throughput went from 6MB/s to 60MB/s. And yes, the Realtek NIC was a gigabit NIC. But hey, don't take my word for it. Try the test yourself.
If you are not doing anything fancy like nic bonding or running jumbo frames then the realtek will suffice. Most of the performance increases will be from makeing changes to your network infrastructure downstream to increase be that througput or reliability.
IPVMU Certified | 01/23/14 10:08pm
I didn't use jumbo frames or bonding in my test. Here is the setup:
PC (64-bit Windows-7 with motherboard based Intel NIC) <--> SMC Gigabit Switch <--> NAS (64-bit FreeNAS)
The only thing that I changed during the test was using the Realtek NIC vs. the Intel NIC on the NAS. The NAS was just another PC I built running FreeNAS with hard drives running RAID5.
Of course if I would have had a RealTek NIC on my Windows-7 PC instead of the Intel NIC, there would have been no performance difference. BTW, I'm not trying to single out RealTek for poor performance as I have noticed similar poor performance while using Broadcom and others. It's more of an endorsement of Intel NIC performance. Going forward, I now only buy motherboards with Intel NICs.
I think the recent posts more likely show a better driver than better hardware. I agree with the comments about keeping the bandwidth consumption down around 30%. I'd still rather not use Intel because I don't want weirdo fancy features that will be painful to re-create down the road when the hardware dies and one needs to replace the system. Jumboframes and bonding are cute but insecure and much less interoperable features. If you need that stuff your system's probably overloaded.