Is Uptime Institute’s data center tier system worth it?

By Mark Fontecchio,

Uptime Institute's data center tiers have been around since the mid-1990s and have become a major standard of data center reliability. The system includes four tiers, where Tier 1 is the least available and Tier 4 the most robust. The basic concepts have stayed the same, although Uptime has expanded the tiers to adjust to a changing industry.

But in recent years, Uptime said that the tier system has been misused. Companies started boasting "Tier 2-plus" status or a "near-Tier 3" data center, designations that Uptime doesn't recognize. Colocation and hosting data centers frequently send out press releases claiming Tier 3 or 4 status, even if they haven't been officially certified. And now the group is trying to recapture control of the system.

But some say the cat's out of the bag, the actual certification doesn't matter, and the tier system is either outdated or too strict to work.

Tier 3 is worth the trouble

OnePartner's Advanced Technology and Applications Center (ATAC) is the only colocation or hosting data center in the U.S. that is certified Tier 3 by ComputerSite Engineering, the firm that works with the Uptime Institute. In the U.S., there are no certified Tier 4 data center colocation or hosting companies, a fact that may come as a surprise to some, seeing that hosting companies regularly claim Tier 3 or Tier 4 status.

OnePartner's 9,200-square-foot facility is tucked in southwestern Virginia near the Tennessee and Kentucky borders. Tom Deaderick, the director of the company, said a major factor in getting Uptime Institute data center tier classification was hiring Thomas "Mac" Scofield as data center manager in 2007. Scofield came to the company with 18 years of experience in data center management.

"We started looking around [for] standards and saw Uptime's," Deaderick said. "That's where things started for us. We wanted to have a standard we could rely on. We're a conservative company, and we don't want to say things that we can't back up."

What is the significance of Uptime Institute Tier 3 certification? According to Uptime, it means having redundant capacity components, multiple independent power distribution paths serving IT equipment, and all IT equipment being dual-powered. It sounds fairly simple. But in OnePartner's case, it required about four times more documentation than usual, including design drawings and electrical diagrams.

It also meant spending more money. During the initial design, OnePartner found that one large Liebert cooling unit would cover an entire server room. But the Uptime Institute allows only 75% of the nameplate value to be counted, and this factor, in combination with the need for redundancy, forced the company to buy two more Liebert cooling units.

"That's the kind of gut check you're faced with," Deaderick said.

But it was worth it, he said. The company can guarantee a certain level of uptime through a third party. And now it receives serious inquiries from government agencies that require an Uptime Institute Tier 3 data center. Finally, Deaderick said, the cost for certification was only about 1% of the total cost of building the $4.5 million data center.

Julian Kudritzki is the certification manager for ComputerSite Engineering Inc., the engineering and consulting firm that works in close concert with the Uptime Institute, and added that certification affords legal protection. He mentioned an unnamed commercial data center in the Netherlands. It had a service-level agreement with one customer that ensured it was a Tier 3 data center, even though it wasn't Uptime-certified. There was an outage. The customer got ready to file a lawsuit, so the commercial data center asked the Uptime Institute to visit in the hopes of getting it Tier 3- certified. But no such luck.

"They were a bare-bones Tier 1," Kudritzki said, adding that the Uptime Institute left without giving the company the certification it sought.

Some tiers are better than none

Many data center operators disagree with OnePartner that the certification is worth the trouble, as evidenced by the fact that only a few dozen data centers worldwide are certified Tier 3 or Tier 4 by Uptime. Peter Sacco, the president of New Jersey-based engineering firm PTS Data Center Solutions, said that while the Uptime tiers represent a valuable classification system, it has problems.

In particular, Sacco has criticized Uptime's claims that there is no such thing as a partial tier site, such as a Tier 1-plus or an almost Tier 3. Uptime claims those misnomers constitute tier standard misuse.

"While I understand the argument that a site is only as good as its weakest link, to say that a site incorporating most but not all the elements of the tier definition is mathematically and experientially wrong," Sacco wrote on his Data Center Design site. "PTS' actual experiences bear this out. Our clients that have all the elements of a Tier 2 site, except for the second generator, are clearly better than those with no UPS [uninterruptible power supply] and/or air conditioning redundancy [Tier I]. Therefore, if not for Tier I-plus, how do they suggest to account for the vast realization between the real availability of the two sites?"

Another critic is Lifeline Data Centers, an Indianapolis-based data center colocation and hosting company. Doug Theis, the vice president of business development, wrote recently that a Tier 4 data center requires a raised floor at least 3 feet deep. Lifeline builds solid-floor data centers with overhead cooling.

"The benefits of solid floor are lower installation and maintenance costs, more reliable floor loading, and cleaner cable and power management with better airflow," Theis wrote. "And many solid-floor proponents say that they can cool the densest implementations just as well in solid floor data center as in a raised-floor environment."

Uptime disputes that a Tier 4 data center must have a raised floor. It contends that a Tier 4 data center must have everything a Tier 3 center has, and be fully fault tolerant through electrical, storage and distribution networks, And all cooling equipment [including chillers] must be independently dual-powered.

"The tiers are based on fundamental concepts," Kudritzki said. "Tier 3, for example, is based on concurrent maintenance. Every capacity and distribution component can be taken out and maintained without affecting uptime. The concepts haven't changed."

"We frequently get questions like, 'Where is our design cookbook?'" Kudritzki continued. "But there isn't one. There are many preferences different data centers might have. The tiers are about configuration and functionality."

About OnePartner The OnePartner ATAC data center is the first commercial data center in North America to receive a Tier III certification by The Uptime Institute. The ATAC data center has provided uninterrupted service since 2008. Organizations interested in OnePartner services will find more information at

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