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docs.it4i/general/energy.md

+# Energy Saving
+
+Due to high energy prices and reductions in funding, a set of energy saving measures are implemented in the  IT4Innovations National Supercomputer Center operation. The measures are selected such as to minimize the performance impact and achieve significant cost and enegy saving effect.
+
+The energy saving measures are in force as of 31.1.2023.
+
+## Karolina
+
+### Measures
+
+|Measure                                                  | Value   |
+|---------------------------------------------------------|---------|
+|Compute nodes cn[001-720]<br> CPU core frequency capping | 2.100 GHz |
+|Accelerated compute nodes acn[001-72]<br> CPU core frequency capping | 2.600 GHz  |
+|Accelerated compute nodes acn[001-72]<br> GPU core frequency capping | 1.290 GHz |
+
+### Performance Impact
+
+The performance impact depends strongly on the [arithmetic intensity][1][][2] of the job.
+
+### Energy Saved
+
+## Barbora
+
+None implemented yet.
+
+## NVIDIA DGX-2
+
+None implemented yet.
+
+## Complementary systems 
+
+None implemented yet.
+
+[1]: https://people.eecs.berkeley.edu/~kubitron/cs252/handouts/papers/RooflineVyNoYellow.pdf
+[2]: https://en.wikipedia.org/wiki/Roofline_model