RSC Direct Liquid Cooling Technology (DLCT)

Cooling systems are one of the main contributors in overall power consumptions of modern data centers based on HPC systems or server farms. Cooling system power consumption may vary from 2-6% to 60-70% of total for a data center. Such difference is achieved by improving efficiency of heat diversion from heat generating elements such as servers, storage systems, communication subsystems. Servers contribute 90-95% to total volume of heat generation, and therefore heat dissipation in modern data centers requires construction of the most efficient system for diverting heat from the server array.

RSC direct liquid cooling technology ensures precise diversion of heat from server through a cooling plate that fully covers all element-containing surface of a computing node and is cooled with liquid. This approach enables most complete heat transfer from the entire area of server components except local overheating and air pockets. This increases lifetime of electronic components and improves overall solution redundancy.

	Technology applied to RSC can be used to implement liquid cooling for standard server boards, processors and memory as well as additional expansion cards such as accelerators, coprocessors, I/O cards, etc. Efficient direct liquid cooling is provided for all expansion elements as well.
RSC Tornado Node		RSC Tornado Node with two Intel Xeon Phi

RSC direct liquid cooling technology was the basis for creating RSC Tornado Cluster Architecture that enables high-density installation of servers to a rack with direct liquid cooling. RSC Tornado Cluster Architecture can be used to pack up to 128 servers into a 80х80х200 cm rack. Such architecture can divert up to 100 kW of heat energy from one rack. More efficient heat transfer mechanism implemented in a liquid cooling system provides significant power savings as compared to traditional air convection systems and forced cooling systems. Free cooling enables  PUE (power usage effectiveness) factor 1.06, i.e. no more than 6% of consumed electrical power is used for cooling purposes. Cooling costs are reduced by up to 68 % as compared to air or air-water cooling systems (that have a typical PUE = 1.5-2).

Experimental data

Impact of temperature on system redundancy:

• When the temperature is increased by 10°C, reliability of electronic devices that have long term of operation is reduced by 50%.
•  Temperature increase by 15°C doubles hard disk failure frequency

Comparative testing of systems based on air and liquid RSC cooling solutions

Cooling	Air	Liquid
Application	NAMD V.2.9 (2012-04-30), x86_64, ICC12.1, –O3 –xAVX
Test	ApoA1 (92224 atoms, 65000 steps, 12A cutoff+PME 4 steps, periodic)
Processor	Intel® Xeon® E5-2690step C2, (2.90 GHz, 8 cores, 20M cash, 8.00 GT/s Intel® QPI)
Memory	64GB (8*8GB DDR3-1600 Samsung® PC3-12800 ECC Reg. DIMM, part number: M392B1K70DM0-CK0)
Server Board	Intel Server Board S2600JFF
Cooling system	3x default fans Intel Server H2200JF, Tinlet=17С	RSC Direct Liquid Cooling Technology
Compute node

	Air cooling	Liquid cooling	Delta
Test run time	63 min. 21 sec. (3801 seconds)	59 min. 29sec. (3569 seconds)	6,5% (1,065х)
Average Electric Power	491 W	425 W	15,5% (1,155х)
Power Consumption	0,518 kW/h	0,421 kW/h	23% (1,230х)
PUE	1,6	1,06	50% (1,5х)
Total power consumption	0,83 kW/h	0,44 kW/h	88% (1,88х)

Resume. Benefits of RSC Direct Liquid Cooling Technology usage:

• Up to 2x power consumption reduction;

• Test time reduction.