Intel’s TV marketing campaign says the company is driving 98 percent of the cloud. That statistic will come under attack with some chip and OS announcements on Wednesday.

The most significant announcement: Microsoft’s Windows Server OS now running on ARM chips. The OS was exclusive to x86 chips, but now customers can consider ARM chips to run Windows Server.

Microsoft did not announce an official date for an ARM version of Windows Server, though the software company is using such systems internally. The announcement was made on the opening day of Open Compute Project’s U.S. Summit in Santa Clara, California.

At the summit, Qualcomm showed a new 48-core 1U server running its Centriq 2400 ARM chip. The server is based on Microsoft’s Project Olympus server design and was shown running Windows Server. It was designed for the Azure cloud at Microsoft. The Centriq 2400 chip isn’t available commercially but is still in testing.

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ARM servers represent a “real opportunity, and some Microsoft cloud services already have future deployment plans on ARM servers,” van Doorn said.

Many other companies like Dell and Lenovo have similarly talked glowingly about ARM servers in the past but failed to deliver stable systems. Most web servers run Linux, and ARM has failed to break into that market despite its chips working well with the LAMP (Linux, Apache, MySQL, and PHP) stack.

The issue with ARM chips on Linux servers has been the same as on Microsoft — a lack of software and performance questions. Intel’s Xeon server chips still remain among the fastest.

For its part, ARM is thrilled to have Microsoft as a partner in servers. It’s a big break the company needs to expand into the server and infrastructure market, which is highly profitable. ARM already dominates in mobile, wearables, and internet-of-things devices, and the architecture will be returning to Windows laptops later this year via Qualcomm’s Snapdragon 835 chips. The server market has eluded ARM so far, and it hasn’t challenged Intel.

In a blog entry, ARM and Microsoft said both the companies combined will be “change-makers.” But that’s hard to see considering ARM chips and Microsoft’s Windows Server are small players in the server market. 

Intel said the server market is competitive, and it takes all products seriously.

“We are confident that Xeon processors will continue to deliver the highest performance and lowest total cost of ownership for our cloud customers. However, we understand the desire of our customers to evaluate other product offerings,” Dan Francisco, an Intel spokesman, said in a statement.

Intel may seem calm, but internally, the company may be planning a way to counter the announcement by ARM and Microsoft. When the excitement around ARM server chips started spreading as early as 2011, Intel countered with low-power Atom chips for microservers, which doused the enthusiasm around ARM.

Outside of Qualcomm and Cavium, other ARM chip makers were also active at Open Compute Summit on Wednesday.

Macom showed off its X-Gene 3 chip for servers, storage, and networking devices. The chip was developed by AppliedMicro, which was by Macom earlier this year.

The X-Gene 3 has impressive features on paper. It has up to 32 cores, support for DDR4 memory, and 42 PCI-Express 3.0 lanes for fast throughput. It has 32MB of L3 cache shared across all cores and 256KB of cache for every two cores. The new chip will deliver more than five times the performance of an X-Gene 2, which has only eight cores. The X-Gene 3, however, draws more power than its predecessor.

The new Macom chip will start shipping to testers this month. The final shipment date for the chip wasn’t announced.