diff --git a/src/resource_pool.go b/src/resource_pool.go
index 9e9639d..8eb7742 100644
--- a/src/resource_pool.go
+++ b/src/resource_pool.go
@@ -9,6 +9,7 @@ import (
 	"math/rand"
 	"strconv"
 	"hash/fnv"
+	"sort"
 )
 
 type ResourcePool struct {
@@ -303,16 +304,82 @@ func (pool *ResourcePool) getBindings() map[string]map[string]int {
 	return pool.bindings
 }
 
-func (pool *ResourcePool) pickNode(nodes []*NodeStatus) *NodeStatus {
+func (pool *ResourcePool) pickNode(candidates []*NodeStatus, availableGPUs map[string][]GPUStatus, task Task, job Job, nodes []NodeStatus) *NodeStatus {
 
 	/* shuffle */
 	r := rand.New(rand.NewSource(time.Now().Unix()))
-	for n := len(nodes); n > 0; n-- {
+	for n := len(candidates); n > 0; n-- {
 		randIndex := r.Intn(n)
-		nodes[n-1], nodes[randIndex] = nodes[randIndex], nodes[n-1]
+		candidates[n-1], candidates[randIndex] = candidates[randIndex], candidates[n-1]
 	}
 
 	/* sort */
+	// single node, single GPU
+	sort.Slice(candidates, func(a, b int) bool {
+		diffA := pool.GPUModelToPower(candidates[a].Status[0].ProductName) - pool.GPUModelToPower(task.ModelGPU)
+		diffB := pool.GPUModelToPower(candidates[b].Status[0].ProductName) - pool.GPUModelToPower(task.ModelGPU)
 
-	return nodes[0]
+		if diffA > 0 && diffB >= 0 && diffA > diffB {
+			return false //b
+		}
+		if diffA < 0 && diffB < 0 && diffA > diffB {
+			return false
+		}
+		if diffA < 0 && diffB >= 0 {
+			return false
+		}
+		if diffA == diffB {
+			if len(availableGPUs[candidates[a].ClientID]) == len(availableGPUs[candidates[b].ClientID]) {
+				return candidates[a].UtilCPU > candidates[b].UtilCPU
+			}
+			return len(availableGPUs[candidates[a].ClientID]) < len(availableGPUs[candidates[b].ClientID])
+		}
+		return true //a
+	})
+
+	var t []*NodeStatus
+	bestGPU := candidates[0].Status[0].ProductName
+	for _, node := range candidates {
+		if node.Status[0].ProductName != bestGPU {
+			break
+		}
+		t = append(t, node)
+	}
+	candidates = t
+
+	if (len(job.Tasks) == 1) && task.NumberGPU > 1 { //single node, multi GPUs
+		sort.Slice(candidates, func(a, b int) bool {
+			if len(availableGPUs[candidates[a].ClientID]) == len(availableGPUs[candidates[b].ClientID]) {
+				return candidates[a].UtilCPU > candidates[b].UtilCPU
+			}
+			return len(availableGPUs[candidates[a].ClientID]) < len(availableGPUs[candidates[b].ClientID])
+		})
+	}
+
+	if len(job.Tasks) > 1 { //multi nodes, multi GPUs
+		sort.Slice(candidates, func(a, b int) bool {
+			distanceA := 0
+			distanceB := 0
+			for _, node := range nodes {
+				if node.Rack != candidates[a].Rack {
+					distanceA += 10
+				}
+				if node.ClientID != candidates[a].ClientID {
+					distanceA += 1
+				}
+				if node.Rack != candidates[b].Rack {
+					distanceB += 10
+				}
+				if node.ClientID != candidates[b].ClientID {
+					distanceB += 1
+				}
+			}
+			if distanceA == distanceB {
+				return len(availableGPUs[candidates[a].ClientID]) > len(availableGPUs[candidates[b].ClientID])
+			}
+			return distanceA*job.Locality < distanceB*job.Locality
+		})
+	}
+
+	return candidates[0]
 }
diff --git a/src/scheduler_fair.go b/src/scheduler_fair.go
index 7c7ec46..242e2d7 100644
--- a/src/scheduler_fair.go
+++ b/src/scheduler_fair.go
@@ -330,10 +330,9 @@ func (scheduler *SchedulerFair) AcquireResource(job Job, task Task, nodes []Node
 							for task_t, s := range tasks {
 								est, valid2 := InstanceOfOptimizer().predictTime(task_t)
 								if valid2 {
-									t := s
 									now := (int)(time.Now().Unix())
-									log.Info(t, now, estimate, est)
-									if now-t > est.Total-est.Post-estimate.Pre && status.MemoryFree > task.MemoryGPU {
+									log.Info(s, now, estimate, est)
+									if now-s > est.Total-est.Post-estimate.Pre-15 && status.MemoryFree > task.MemoryGPU {
 										available = append(available, status)
 									}
 								}
@@ -363,7 +362,7 @@ func (scheduler *SchedulerFair) AcquireResource(job Job, task Task, nodes []Node
 
 	/* assign */
 	if len(candidates) > 0 {
-		node := pool.pickNode(candidates)
+		node := pool.pickNode(candidates, availableGPUs, task, job, nodes)
 		res.ClientID = node.ClientID
 		res.ClientHost = node.ClientHost
 		res.Status = availableGPUs[node.ClientID][0:task.NumberGPU]
diff --git a/src/util.go b/src/util.go
index df973a1..d091ebe 100644
--- a/src/util.go
+++ b/src/util.go
@@ -111,6 +111,7 @@ type GPUStatus struct {
 type NodeStatus struct {
 	ClientID     string      `json:"id"`
 	ClientHost   string      `json:"host"`
+	Rack         int         `json:"rack"`
 	Version      float64     `json:"version"`
 	NumCPU       int         `json:"cpu_num"`
 	UtilCPU      float64     `json:"cpu_load"`
@@ -130,6 +131,7 @@ type Job struct {
 	CreatedAt int         `json:"created_at"`
 	UpdatedAt int         `json:"updated_at"`
 	CreatedBy int         `json:"created_by"`
+	Locality  int         `json:"created_by"`
 	Status    State       `json:"status"`
 }