What upgrades and modifications have the biggest positive impact on your data center’s energy efficiency?

If roughly half of the worlds data centers are still enterprise-class, many supposedly reaching the end of life and running legacy equipment, then surely a "quick win" would be to upgrade them with the latest infrastructure technologies so that they run more efficiently. Cost is almost always a prohibitive factor when it comes to data center upgrades and retrofits or more precisely explaining the ROI to management or the Board especially when so many alternatives for new capacity are available as Hybrid IT is embraced.

We ask our panel of data center operators and their expert advisors for their insights on making the right technology decisions and justifying extending the life of existing data center facilities.