diff --git a/ggml/include/ggml-rpc.h b/ggml/include/ggml-rpc.h
index cbfe400139..1f8cb7906c 100644
--- a/ggml/include/ggml-rpc.h
+++ b/ggml/include/ggml-rpc.h
@@ -6,7 +6,7 @@
 extern "C" {
 #endif
 
-#define RPC_PROTO_MAJOR_VERSION    6
+#define RPC_PROTO_MAJOR_VERSION    7
 #define RPC_PROTO_MINOR_VERSION    0
 #define RPC_PROTO_PATCH_VERSION    0
 
diff --git a/ggml/src/ggml-rpc/ggml-rpc.cpp b/ggml/src/ggml-rpc/ggml-rpc.cpp
index cc7d720693..adb88a2456 100644
--- a/ggml/src/ggml-rpc/ggml-rpc.cpp
+++ b/ggml/src/ggml-rpc/ggml-rpc.cpp
@@ -697,10 +697,31 @@ static void ggml_backend_rpc_buffer_memset_tensor(
     ctx->dispatcher->send(RPC_CMD_MEMSET_TENSOR, request, sizeof(*request));
 }
 
+// input serialization format: | rpc_tensor | cache_flag (1 byte) | offset (8 bytes) | data (size bytes)
+static std::shared_ptr<uint8_t> serialize_set_tensor(const rpc_tensor & rpc_tensor, uint8_t cache_flag, uint64_t offset, const void * data, size_t size, size_t & input_size) {
+    input_size = sizeof(rpc_tensor) + sizeof(cache_flag) + sizeof(offset) + size;
+    uint8_t * input = new uint8_t[input_size]();
+    uint8_t * p = input;
+    memcpy(p, &rpc_tensor, sizeof(rpc_tensor)); p += sizeof(rpc_tensor);
+    memcpy(p, &cache_flag, sizeof(cache_flag)); p += sizeof(cache_flag);
+    memcpy(p, &offset,     sizeof(offset));     p += sizeof(offset);
+    memcpy(p, data, size);
+    return std::shared_ptr<uint8_t>(input, std::default_delete<uint8_t[]>());
+}
+
+// the hash cache is meant for weights, so that a model reload can skip re-sending them.
+// compute-buffer inputs (the activations ggml_backend_sched copies between backends) must not
+// take this path, otherwise with `rpc-server -c` every ubatch above the threshold is written
+// to the cache directory and later served from there.
+static bool rpc_use_hash_cache(const ggml_tensor * tensor, size_t size) {
+    return size > HASH_THRESHOLD && tensor->buffer->usage == GGML_BACKEND_BUFFER_USAGE_WEIGHTS;
+}
+
 static void ggml_backend_rpc_buffer_set_tensor(ggml_backend_buffer_t buffer, ggml_tensor * tensor, const void * data, size_t offset, size_t size) {
     ggml_backend_rpc_buffer_context * ctx = (ggml_backend_rpc_buffer_context *)buffer->context;
     rpc_tensor rpc_tensor = serialize_tensor(tensor);
-    if (size > HASH_THRESHOLD) {
+    uint8_t cache_flag = 0;
+    if (rpc_use_hash_cache(tensor, size)) {
         auto request = std::make_shared<rpc_msg_set_tensor_hash_req>();
         request->tensor = rpc_tensor;
         request->offset = offset;
@@ -711,15 +732,12 @@ static void ggml_backend_rpc_buffer_set_tensor(ggml_backend_buffer_t buffer, ggm
             // the server has the same data, no need to send it
             return;
         }
+        // the server has no cache entry for this tensor - ask it to save one
+        cache_flag = 1;
     }
-    // input serialization format: | rpc_tensor | offset (8 bytes) | data (size bytes)
-    size_t input_size = sizeof(rpc_tensor) + sizeof(uint64_t) + size;
-    uint8_t * input = new uint8_t[input_size]();
-    memcpy(input, &rpc_tensor, sizeof(rpc_tensor));
-    memcpy(input + sizeof(rpc_tensor), &offset, sizeof(offset));
-    memcpy(input + sizeof(rpc_tensor) + sizeof(offset), data, size);
-    std::shared_ptr<uint8_t> input_ptr(input, std::default_delete<uint8_t[]>());
-    ctx->dispatcher->send(RPC_CMD_SET_TENSOR, input_ptr, input_size);
+    size_t input_size;
+    auto input = serialize_set_tensor(rpc_tensor, cache_flag, offset, data, size, input_size);
+    ctx->dispatcher->send(RPC_CMD_SET_TENSOR, input, input_size);
 }
 
 static void ggml_backend_rpc_buffer_get_tensor(ggml_backend_buffer_t buffer, const ggml_tensor * tensor, void * data, size_t offset, size_t size) {
@@ -927,7 +945,8 @@ static void ggml_backend_rpc_free(ggml_backend_t backend) {
 static void ggml_backend_rpc_set_tensor_async(ggml_backend_t backend, ggml_tensor * tensor, const void * data, size_t offset, size_t size) {
     ggml_backend_rpc_context * ctx = (ggml_backend_rpc_context *)backend->context;
     rpc_tensor rpc_tensor = serialize_tensor(tensor);
-    if (size > HASH_THRESHOLD) {
+    uint8_t cache_flag = 0;
+    if (rpc_use_hash_cache(tensor, size)) {
         auto request = std::make_shared<rpc_msg_set_tensor_hash_req>();
         request->tensor = rpc_tensor;
         request->offset = offset;
@@ -939,15 +958,12 @@ static void ggml_backend_rpc_set_tensor_async(ggml_backend_t backend, ggml_tenso
             // the server has the same data, no need to send it
             return;
         }
+        // the server has no cache entry for this tensor - ask it to save one
+        cache_flag = 1;
     }
-    // input serialization format: | rpc_tensor | offset (8 bytes) | data (size bytes)
-    size_t input_size = sizeof(rpc_tensor) + sizeof(uint64_t) + size;
-    uint8_t * input = new uint8_t[input_size]();
-    memcpy(input, &rpc_tensor, sizeof(rpc_tensor));
-    memcpy(input + sizeof(rpc_tensor), &offset, sizeof(offset));
-    memcpy(input + sizeof(rpc_tensor) + sizeof(offset), data, size);
-    std::shared_ptr<uint8_t> input_ptr(input, std::default_delete<uint8_t[]>());
-    ctx->dispatcher->send_async(RPC_CMD_SET_TENSOR, input_ptr, input_size);
+    size_t input_size;
+    auto input = serialize_set_tensor(rpc_tensor, cache_flag, offset, data, size, input_size);
+    ctx->dispatcher->send_async(RPC_CMD_SET_TENSOR, input, input_size);
 }
 
 static void ggml_backend_rpc_get_tensor_async(ggml_backend_t backend, const ggml_tensor * tensor, void * data, size_t offset, size_t size) {
@@ -1398,14 +1414,17 @@ ggml_tensor * rpc_server::deserialize_tensor(struct ggml_context * ctx, const rp
 
 
 bool rpc_server::set_tensor(const std::vector<uint8_t> & input) {
-    // serialization format: | rpc_tensor | offset (8 bytes) | data (size bytes) |
-    if (input.size() < sizeof(rpc_tensor) + sizeof(uint64_t)) {
+    // serialization format: | rpc_tensor | cache_flag (1 byte) | offset (8 bytes) | data (size bytes) |
+    uint8_t  cache_flag;
+    uint64_t offset;
+    const size_t header_size = sizeof(rpc_tensor) + sizeof(cache_flag) + sizeof(offset);
+    if (input.size() < header_size) {
         return false;
     }
     const rpc_tensor * in_tensor = (const rpc_tensor *)input.data();
-    uint64_t offset;
-    memcpy(&offset, input.data() + sizeof(rpc_tensor), sizeof(offset));
-    const size_t size = input.size() - sizeof(rpc_tensor) - sizeof(offset);
+    memcpy(&cache_flag, input.data() + sizeof(rpc_tensor), sizeof(cache_flag));
+    memcpy(&offset,     input.data() + sizeof(rpc_tensor) + sizeof(cache_flag), sizeof(offset));
+    const size_t size = input.size() - header_size;
 
     struct ggml_init_params params {
         /*.mem_size   =*/ ggml_tensor_overhead(),
@@ -1434,8 +1453,8 @@ bool rpc_server::set_tensor(const std::vector<uint8_t> & input) {
         }
     }
 
-    const void * data = input.data() + sizeof(rpc_tensor) + sizeof(offset);
-    if (cache_dir && size > HASH_THRESHOLD) {
+    const void * data = input.data() + header_size;
+    if (cache_dir && cache_flag) {
         uint64_t hash = fnv_hash((const uint8_t*)data, size);
         char hash_str[17];
         snprintf(hash_str, sizeof(hash_str), "%016" PRIx64, hash);