CoolIT’s 4000W Coldplate Establishes Single-Phase Direct Liquid Cooling Technology Leadership

Calgary, AB, March 13, 2025 – CoolIT Systems (CoolIT), the world’s leader in liquid cooling for AI and high performance computing, is pleased to announce a 4000W-ready single-phase direct liquid cooling (DLC) coldplate – more than doubling the previously accepted limits of single-phase direct liquid cooling.

“CoolIT continues to lead the industry in performance.  We are thrilled to show silicon leaders that single-phase DLC will continue to be a key enabling technology with demonstrated capability for up to 4000W processors,” said Kamal Mostafavi, VP of Engineering.  “Single-phase direct liquid cooling – known for being the most mature, reliable and scalable liquid cooling technology – is also more than capable of cooling ultra-high watt microprocessors for the foreseeable future.”

Figure 1: CoolIT 4000W coldplate with Split-Flow technology

Single-phase DLC works by removing heat from semiconductors with water or a water-glycol mixture running through coldplates attached to the chips. It is the most widely deployed liquid cooling technology in the market today¹ and the de facto liquid cooling standard for AI processors exceeding 1000W TDP².

In its tests, CoolIT showed its coldplate capturing 97%+ of heat from a 4000W thermal test vehicle (TTV) with a flow rate of 6 litres per minute (LPM). This is equivalent to 1.5 LPM per kW, the semiconductor industry’s recommended flow rate for high-wattage chips. Tests at a lower flow rate also showed excellent results.   

CoolIT’s 4000W coldplates also achieve an outstanding ultra-low thermal resistance of Tr<0.009 C/W while limiting the full flow loop pressure drop (including all fittings and QDs) to just 8 PSI.  

Used for multiple server generations by most of the world’s major server manufacturers, CoolIT’s coldplates with Split-Flow^TM technology delivers 30% better thermal and flow performance than standard coldplates with the added ability to provide targeted cooling to hot spots.

The 4000W test results prove that CoolIT’s DLC technology is well-positioned to cool ultra-high-wattage semiconductors well into the future. For more information, download the technical brief below.