Today we have our review of the Dell EMC 4GMN7 or Broadcom 57404. Broadcom makes this 25GbE NIC for Dell EMC servers. That includes enhancements such as integration for iDRAC. At the same time, they function as standard PCIe devices. 25GbE networking is a major trend in the 2020’s so we are focusing more on that ecosystem. You may have seen the recent Ubiquiti UniFi USW-Leaf Switch Overview with 48x 25GbE and 6x 100GbE ports or our Supermicro AOC-S25G-i2S adapter review. This is going to continue that series.
Dell EMC 4GMN7 / Broadcom 57404 Overview
The card itself is a passively cooled unit with two SFP28 ports. SFP28 is an evolution of the 10GbE era SFP+ ports that are used for 25GbE. We found these cards are backward compatible with 10GbE SFP+ networking as well.
The overall card itself if a low-profile PCIe 3.0 x8 device. It is designed to accommodate low-profile slots but one can use a full-height bracket as well.
The back of the card contains a variety of stickers showing the Dell EMC and Broadcom (BCM) part numbers. This is part of the Broadcom NetXtreme E-series of network adapters.
Dell EMC 4GMN7 / Broadcom 57404 Key Specs
Instead of re-inventing the wheel, here are the key features and specs for the card from Dell and Broadcom:
As you can see, these particular cards have optimizations to work with Dell’s iDRAC. At the same time, we have tried them in Inspur, Supermicro, Gigabyte, and Tyan Xeon Scalable-based servers and they worked like normal NICs. You are also going to notice the conspicuous absence of iWARP and RoCE acceleration that one finds on newer NICs. These are older cards, so we see them more as a value play. Otherwise, something like the Mellanox ConnectX-4 Lx will make more sense.
Dell EMC 4GMN7 / Broadcom 57404 in Linux
We wanted to take a few moments to show our readers what these NICs look like installed. Here is a look at the lshw output:
Here is the NIC in ethtool:
Here is the lspci -vvv output for the NIC:
When we had taken these screenshots we apparently took them off the disconnected port. That is a point of improvement for the next review.
Dell EMC 4GMN7 / Broadcom 57404 Performance
We tested the Dell EMC 4GMN7 / Broadcom 57404 using a 1m breakout SFP28 DAC to our 32-port 100GbE Dell Z9100-ON data center switch. We then varied the port speed and connection type for iperf3.
Overall, these are solid results that are in-line with what we saw from the Intel solution, albeit slightly slower. Given the aging feature set, we would suggest that one does not look as these NICs for the absolute highest performance.
At this point, it the Dell EMC 4GMN7 and Broadcom 57404 is a solid option for Dell EMC servers so long as the price is right and the application does not call for acceleration that these NICs cannot provide. The pockets where these NICs are popular should be seeing them at reasonable pricing. On the other hand, if workloads and offload needs change, it may be better to look at updated 25GbE adapters.