Intel Ethernet X520-SR2 Server Adapter

We use these 10Gb Ethernet adapters in a pair of Dell R720xd servers running Red Hat Linux. The servers perform disk-to-disk backups of other servers in our business environment. The 10Gb NICs help us backup large data sets with enhanced throughput. A big help. Easy to setup. Highly recommended.

So we ordered one of these cards and it came in and we've installed it in a system and it works beautifully. So good for the value we ordered another one of these cards. Same exact card- went to the previous order and hit order again in Amazon order history. But this time the card doesnt have ANY SFP+ modules in them. Now I have to source them, and if I want vmware compatibility I have to use Twinax SFP+ or if I really want fiber, I'll have to use expensive Intel branded optics. I don't think FS.com optics work in vmware - even if coded as Intel.So its really a random what you'll end up getting. Our first one seemed 100% genuine. This one, no sfp modules. Other reviewers note they recieved off brand SFP+ modules like Finistar. They wont work in VMWare because some kind of joint agreement VMware and Intel must have made years ago to ensure people spend money on Intel branded optics.

We put these in our Dell R820 servers running VMWare and learned a valuable lesson. VMWare doesn't not support them unless you are using a twinax cable or an Intel SFP. I tried many different 10GB SFP's but no luck. They will light up but ESXi 5 and up does not list it as a valid SFP so they are shutdown. I found a KB article which talks about this and VMWare confirmed.

Very good

This is not an X520-SR2. An X520-SR2 includes 2 x Intel Ethernet SFP+ SR Optics (E10GSFPSR). The X520-SR2 we purchased came with 2 x Finisar FTLX8571D3BCV SFP+. This NIC with Finisar SFP+ will NOT work under ESXi (as another reviewer pointed out) (look for the `failed to load because an unsupported SFP+ or QSFP module type was detected` in /var/log/vmkernel.log).We speculate that is either an X520-DA2 with Finisar SFP+ or a X520-SR2 with the native Intel SFP+ swapped out for Finisar SFP+. We believe that this was on oversight on the vendor's part.The vendor made good and shipped us the correct SFP+'s when we returned the original ones.