diff --git a/provider/lpproof/treed_build.go b/provider/lpproof/treed_build.go
index 8064d5045..a59ef6624 100644
--- a/provider/lpproof/treed_build.go
+++ b/provider/lpproof/treed_build.go
@@ -5,6 +5,7 @@ import (
 	"github.com/filecoin-project/go-state-types/abi"
 	"github.com/hashicorp/go-multierror"
 	"github.com/ipfs/go-cid"
+	pool "github.com/libp2p/go-buffer-pool"
 	"github.com/minio/sha256-simd"
 	"golang.org/x/xerrors"
 	"io"
@@ -24,6 +25,8 @@ func hashChunk(data [][]byte) {
 
 	d := sha256.New()
 
+	sumBuf := make([]byte, nodeSize)
+
 	for i := 0; i < l1Nodes; i++ {
 		levels := bits.TrailingZeros(^uint(i)) + 1
 
@@ -34,7 +37,7 @@ func hashChunk(data [][]byte) {
 			d.Reset()
 			inNodeData := data[l][inNode*nodeSize : (inNode+2)*nodeSize]
 			d.Write(inNodeData)
-			copy(data[l+1][outNode*nodeSize:(outNode+1)*nodeSize], d.Sum(nil))
+			copy(data[l+1][outNode*nodeSize:(outNode+1)*nodeSize], d.Sum(sumBuf[:0]))
 			// set top bits to 00
 			data[l+1][outNode*nodeSize+nodeSize-1] &= 0x3f
 
@@ -61,8 +64,8 @@ func BuildTreeD(data io.Reader, outPath string, size abi.PaddedPieceSize) (cid.C
 
 	// setup buffers
 	maxThreads := int64(size) / threadChunkSize
-	if maxThreads > int64(runtime.NumCPU()) {
-		maxThreads = int64(runtime.NumCPU())
+	if maxThreads > int64(runtime.NumCPU())*15/10 {
+		maxThreads = int64(runtime.NumCPU()) * 15 / 10
 	}
 	if maxThreads < 1 {
 		maxThreads = 1
@@ -79,11 +82,11 @@ func BuildTreeD(data io.Reader, outPath string, size abi.PaddedPieceSize) (cid.C
 		if bottomBufSize > int64(size) {
 			bottomBufSize = int64(size)
 		}
-		workerBuffer[0] = make([]byte, bottomBufSize)
+		workerBuffer[0] = pool.Get(int(bottomBufSize))
 
 		// append levels until we get to a 32 byte level
 		for len(workerBuffer[len(workerBuffer)-1]) > 32 {
-			newLevel := make([]byte, len(workerBuffer[len(workerBuffer)-1])/2)
+			newLevel := pool.Get(len(workerBuffer[len(workerBuffer)-1]) / 2)
 			workerBuffer = append(workerBuffer, newLevel)
 		}
 		workerBuffers[i] = workerBuffer
@@ -98,13 +101,25 @@ func BuildTreeD(data io.Reader, outPath string, size abi.PaddedPieceSize) (cid.C
 		}
 
 		apexBuf = make([][]byte, 1)
-		apexBuf[0] = make([]byte, apexBottomSize*nodeSize)
+		apexBuf[0] = pool.Get(int(apexBottomSize * nodeSize))
 		for len(apexBuf[len(apexBuf)-1]) > 32 {
-			newLevel := make([]byte, len(apexBuf[len(apexBuf)-1])/2)
+			newLevel := pool.Get(len(apexBuf[len(apexBuf)-1]) / 2)
 			apexBuf = append(apexBuf, newLevel)
 		}
 	}
 
+	// defer free pool buffers
+	defer func() {
+		for _, workerBuffer := range workerBuffers {
+			for _, level := range workerBuffer {
+				pool.Put(level)
+			}
+		}
+		for _, level := range apexBuf {
+			pool.Put(level)
+		}
+	}()
+
 	// start processing
 	var processed uint64
 	var workWg sync.WaitGroup
diff --git a/provider/lpproof/treed_build_test.go b/provider/lpproof/treed_build_test.go
index 5fd28bbd3..6c69c4ed1 100644
--- a/provider/lpproof/treed_build_test.go
+++ b/provider/lpproof/treed_build_test.go
@@ -5,10 +5,12 @@ import (
 	"crypto/rand"
 	"fmt"
 	"github.com/filecoin-project/go-state-types/abi"
+	pool "github.com/libp2p/go-buffer-pool"
 	"github.com/stretchr/testify/require"
 	"io/ioutil"
 	"os"
 	"path/filepath"
+	"runtime"
 	"testing"
 )
 
@@ -273,6 +275,26 @@ func BenchmarkBuildTreeD512M(b *testing.B) {
 		b.Fatalf("Failed to generate random data: %v", err)
 	}
 
+	// preallocate NumCPU+1 1MiB/512k/256k/...
+	// with Pool.Get / Pool.Put, so that they are in the pool
+	{
+		nc := runtime.NumCPU()
+		bufs := [][]byte{}
+		for i := 0; i < nc+1; i++ {
+			for sz := 1 << 20; sz > 32; sz >>= 1 {
+				b := pool.Get(sz)
+				bufs = append(bufs, b)
+			}
+		}
+		for _, b := range bufs {
+			pool.Put(b)
+		}
+	}
+
+	if b.N == 1 {
+		b.N = 10
+	}
+
 	b.SetBytes(int64(dataSize)) // Set the number of bytes for the benchmark
 
 	for i := 0; i < b.N; i++ {