When the Google Cloud Platform (GCP), which underlies Kinsta’s hosting infrastructure, introduced a new generation of hardware to some of its data centers in late 2023, we asked if the technology could make our own platform faster and more reliable.

We’re now migrating customers to these new C3D machines where GCP has made them available because the answer to that question was a resounding yes.

For many customers, C3D VMs will replace the C2 machines that have headlined Kinsta’s cloud story. So, let’s take a closer look at how customers will benefit from this no-cost upgrade.

C3D VMs Get a Real-World Test

“Ensuring top-tier site speed is our North Star, guiding every decision we make,” said Laszlo Farkas, Kinsta’s Director of Engineering. “It remains our number one commitment to our clients, shaping the future of our services.”

Kinsta conducts comprehensive lab tests for every new GCP machine type to assess its performance and resiliency. The lab tests are methodically segmented to accurately compare different machine types. This rigorous approach was used before introducing the C2 machines, and the same process was repeated to evaluate the C3D technology.

“The lab testing is central to our commitment to delivering the best possible performance for client sites,” Farkas said. “However, putting real sites and real client workloads on the machines is also critical.”

Kinsta’s engineering team conducted a thorough assessment over several weeks to gauge the efficiency of a C3D-based host machine that had been operating in production for two months. The investigation revealed that the C3D machine delivered response times 20% to 50% faster than legacy machines in this real-world environment.

Farkas said testers saw the most dramatic speed enhancements in requests for uncached PHP pages. Kinsta’s state-of-the-art edge caching and server-level caching already ensure near-instantaneous delivery for cacheable content, minimizing network latency.

But content that requires individualization, like ecommerce shopping carts or user-specific data, must be processed directly by the WordPress core. The new C3D machine type demonstrated its exceptional capabilities, ensuring rapid response times even for the most complex and dynamic content.

C3D VMs also performed better than the legacy machines during requests for cached content. Still, the dramatic improvement with uncached PHP on C3D-hosted sites is clear in the chart below covering five days of traffic:

Chart showing comparison testing of Google Cloud's C2 and C3D machines.
Response times for C3D-based sites and all sites during requests for uncached PHP pages.

What Makes C3D Machines Different?

The enhanced speed of the C3D machines can be attributed primarily to a more advanced CPU and improved I/O performance.

AMD’s EPYC (Genoa) processor, which has a maximum frequency of 3.7 GHz, powers the C3Ds. They also have a separate infrastructure processing unit (IPU) to relieve the CPU of some computation required for network switching, security, and storage. This combination results in faster and more reliable performance, particularly in demanding hosting environments.

Farkas said the improvements result in quicker PHP execution and more efficient handling of database requests. Beyond speed, the enhanced I/O improves stability, ensuring a more consistent and dependable hosting experience.

Insights From C3D Lab Testing

Kinsta’s automated lab tests focused on key areas such as disk I/O, database performance, and high-traffic server endurance.

Farkas said the testing environment is crafted to replicate real-life scenarios as closely as possible, including running concurrent tests and maintaining multiple containers on each server to simulate actual production hosts.

Here are results highlights:

Web Request Simulation

The team used the Siege HTTP load-testing utility to simulate dozens of concurrent users making as many requests as possible for two minutes.

Machine Type Transactions Avg. Response Time (Sec.)
C3D 93,320 0.04
C2 57,436 0.06

I/O Load Test

The benchmarking tool Bonnie++ was used to test reading from and writing to SSD persistent disks.

Machine Type Write (Mebibytes/Sec.) Read (Mebibytes/Sec.)
C3D 314 118
C2 227 36
Note: One mebibyte equals 1.048576 megabytes.

MySQL Stress Test

The mysqlslap load emulation client simulated dozens of concurrent MySQL connections executing simultaneous queries. “I/O wait” values represent the average lag before a disk read or write operation in response to a query.

Machine Type I/O Wait (Milliseconds)
C3D 0.9
C2 86

“Based on the lab tests, C3D had outstanding performance,” Farkas said.

Power Your Site With C3D Technology

GCP hasn’t yet deployed these powerful C3D machines to all of the 35 data centers used by our customers. We’re monitoring C3D availability and migrating the sites of our Managed WordPress Hosting customers where possible.

However, you can select a C3D-capable data center when you add a new WordPress site. Data centers with C3D machines ready for your next site are flagged as “Boosted” in the data center selection drop-down.

Steve Bonisteel


Steve Bonisteel is a Technical Editor at Kinsta who began his writing career as a print journalist, chasing ambulances and fire trucks. He has been covering Internet-related technology since the late 1990s.