---
title: "didModifyRange:"
framework: metal
role: symbol
role_heading: Instance Method
path: "metal/mtlbuffer/didmodifyrange:"
---

# didModifyRange:

Informs the GPU that the CPU has modified a section of the buffer.

## Declaration

```occ
- (void) didModifyRange:(NSRange) range;
```

## Parameters

- `range`: The range of bytes that were modified.

## Mentioned in

Synchronizing a managed resource in macOS

## Discussion

Discussion If you write information to a buffer created with the MTLStorageMode.managed storage mode, you need to call this method to inform the GPU that the information has changed. If you execute GPU commands that read from the modified sections without calling this method first, the behavior is undefined.