diff --git a/src/Copar/Algorithm/Split.hs b/src/Copar/Algorithm/Split.hs
index 8ac4e47ef4ecc1e120488ebd258e5f12efad91ad..ee9df034ec2ed3248f6728752bbae80d334e1370 100644
--- a/src/Copar/Algorithm/Split.hs
+++ b/src/Copar/Algorithm/Split.hs
@@ -24,7 +24,7 @@ import           Control.Monad.ST
 import           Control.Monad.ST.Unsafe (unsafeSTToIO)
 import           Data.Maybe (maybeToList)
 import           Data.STRef
-import           System.IO.Unsafe (unsafeDupablePerformIO)
+import           System.IO.Unsafe (unsafeDupablePerformIO, unsafePerformIO)
 import           Data.Ord (comparing)
 
 import           Control.Monad.Extra (unlessM, whenM)
@@ -45,11 +45,17 @@ import           Copar.RefinementInterface (RefinementInterface, F3)
 import qualified Copar.RefinementInterface as RI
 import           Copar.Algorithm.Types
 
+import Debug.Trace
+import           System.CPUTime
+
 type SplitM s f = ReaderT (AlgoState s f, BlockQueue s) (ST s)
 
 split :: RefinementInterface f => Block -> SplitM s f ()
 split blockS = do
   (as, _) <- ask
+  let !time = unsafePerformIO getCPUTime
+  size <- lift (Partition.numBlocks (partition as))
+  traceM $ show time <> " " <> show size
   touchedBlocks <- collectTouchedBlocks blockS
 
   forM_ touchedBlocks $ \(b, v0) -> do