diff --git a/samples/net/zperf/README.rst b/samples/net/zperf/README.rst
index 949acba5e76f42c..1bcada04ac99d91 100644
--- a/samples/net/zperf/README.rst
+++ b/samples/net/zperf/README.rst
@@ -36,6 +36,17 @@ This sample application has been tested on the following platforms:
 - Arm FVP BaseR AEMv8-R
 - ARM BASE RevC AEMv8A Fixed Virtual Platforms
 
+For best performance, the sample configures a lot of network packets and buffers.
+Because of this, the sample's RAM requirements are quite large. In case the
+sample does not fit into target platform RAM, reduce the following configs:
+
+.. code-block:: cfg
+
+   CONFIG_NET_PKT_RX_COUNT=50
+   CONFIG_NET_PKT_TX_COUNT=50
+   CONFIG_NET_BUF_RX_COUNT=300
+   CONFIG_NET_BUF_TX_COUNT=300
+
 Requirements
 ************
 
diff --git a/samples/net/zperf/prj.conf b/samples/net/zperf/prj.conf
index 115651dfa2f8fd0..82c09ecf5d9e063 100644
--- a/samples/net/zperf/prj.conf
+++ b/samples/net/zperf/prj.conf
@@ -8,11 +8,11 @@ CONFIG_NET_UDP=y
 CONFIG_NET_TCP=y
 CONFIG_NET_STATISTICS=y
 
-CONFIG_NET_PKT_RX_COUNT=14
-CONFIG_NET_PKT_TX_COUNT=14
-CONFIG_NET_BUF_RX_COUNT=28
-CONFIG_NET_BUF_TX_COUNT=28
-CONFIG_NET_BUF_DATA_SIZE=1500
+CONFIG_NET_PKT_RX_COUNT=50
+CONFIG_NET_PKT_TX_COUNT=50
+CONFIG_NET_BUF_RX_COUNT=300
+CONFIG_NET_BUF_TX_COUNT=300
+CONFIG_NET_BUF_DATA_SIZE=256
 CONFIG_NET_IF_UNICAST_IPV6_ADDR_COUNT=4
 CONFIG_NET_IF_MCAST_IPV6_ADDR_COUNT=5
 CONFIG_NET_IF_UNICAST_IPV4_ADDR_COUNT=1
@@ -40,3 +40,4 @@ CONFIG_LOG=y
 CONFIG_SHELL_CMDS_RESIZE=n
 
 CONFIG_CACHE_MANAGEMENT=y
+CONFIG_SPEED_OPTIMIZATIONS=y