Reasons Killer never took off:
1. It costs way too much
2. Routers already do QoS, which is where you want it anyway, any device on your network is affected. Things like torrents can be done easily without QoS, by limiting the bandwidth used within torrent software. I used to play Diablo 2 online while torrenting with an imperceptible difference in lag simply by setting limit, I think it was like 80%.
3. The latency differences while good percentage-wise, are mostly academic due to 1/10 of a ms not really mattering. If you can get 0.2% lower latency at the cost of increased CPU load, you may be better saving your CPU cycles.
Our test subject in this case is the Z170X-Gaming 7. With its twin GigE interfaces—one Killer-powered and one Intel-powered—it's the perfect candidate for some side-by-side testing.
The Intel's I219-V's minimum round trip latency is 38.3 microseconds, or 71%, longer than the Killer E2400's.
With a 32-byte payload, the results are even more impressive. Here, the Killer has a round-trip latency that is under one-third of what the Intel controller achieves.
The Killer outperfors the Intel controller by a wide margin at small request-and-response sizes, and the margin shrinks as the size increases. The Killer's CPU usage is higher than Intel's, but not more than 1% higher in these tests.
Enabling Bandwidth Control in the Killer Network Manager immediately changed all that. Ping times returned to a much more manageable 50-ms range, and gameplay was pleasant once again. My downloads continued in the background, and I was happily back to "testing" for this article.
Running the same test of Team Fortress 2 gameplay with torrents downloading in the background on the Intel network controller gave the same results as using the Killer with Bandwidth Control disabled—an unplayable experience that left me spending more time waiting to respawn than actually playing the game.
Killer Networking hardware is appearing in more and more motherboards and laptops. It's a long way from the original Killer NICs that polarized so many in the PC hardware world. If you want the features of Killer's networking stack, you no longer have to pay for an add-in PCI or PCIe network card with dedicated network processing hardware.
The real question is whether your next device should have a Killer NIC baked in. The company's software suite does offer some impressive features, like automatic prioritization of game traffic and other latency-sensitive packets. If those features sound valuable for your needs, or you think that it's something you'd like to try out, we have no qualms about recommending a motherboard with Killer Networking onboard.
Our testing showed that the Killer E2400 is a capable Gigabit Ethernet controller, though it did use more CPU time under some network loads compared to an Intel NIC. The Killer E2400 often delivered lower packet latency in exchange for the extra CPU cycles, and its local prioritization voodoo worked as advertised for us, too.
We didn't experience any issues with system stability or crashes, either with the full Killer suite or the company's plain driver—instability being one bit of conventional wisdom that some folks cite as a reason to avoid Killer hardware. If you're wary of an otherwise-ideal motherboard or laptop just because it happens to have Killer-powered networking on board, you can probably relax. Not only can you disable the Bandwidth Control feature of Killer's software, but you can also forgo the company's software suite entirely and just install a plain driver package. If all you want is a basic GigE controller with no frills, the Killer NIC can play that role, too.