http://blogs.msdn.com/shawnhar/archive/2008/04/15/stalls-part-two-beware-of-setdata.aspxajmiles got it in one . This harmless looking code: vertexBuffer.SetData(particlePositions); graphicsDevice.VertexBuffer = vertexBuffer; graphicsDevice.DrawPrimitives(...); will cause a pipeline stall if the CPU reaches the SetData call for frame #2 beforeenCommunityServer 2.1 SP1 (Build: 61025.2)http://blogs.msdn.com/shawnhar/archive/2008/04/15/stalls-part-two-beware-of-setdata.aspx#8398232Wed, 16 Apr 2008 00:12:30 GMT91d46819-8472-40ad-a661-2c78acb4018c:8398232JoelMartinez<p>&quot;Good for dynamic texture scenarios such as video playback.&quot;</p> <p>eeeenteresting</p> http://blogs.msdn.com/shawnhar/archive/2008/04/15/stalls-part-two-beware-of-setdata.aspx#8417264Wed, 23 Apr 2008 00:23:31 GMT91d46819-8472-40ad-a661-2c78acb4018c:8417264bpevangelista<p>Hi Shawn,</p> <p>I've a question. When you use he SetData method in the VertexBuffer class, the vertex buffer is locked, the data is sent to the video card and then it is unlocked, right ??</p> <p>When you lock the vertex buffer you get an address to the buffer. Is this address a virtual address that allow you to direct access the video memory? Or the data is only updated when you call unlock ?</p> <p>Thanks!</p> http://blogs.msdn.com/shawnhar/archive/2008/04/15/stalls-part-two-beware-of-setdata.aspx#8417272Wed, 23 Apr 2008 00:29:09 GMT91d46819-8472-40ad-a661-2c78acb4018c:8417272ShawnHargreaves<p>bpevangelista: in the native DirectX API, it depends: this can work either way depending on the driver and what usage flags you specify.</p> <p>In the XNA Framework, there is no such thing as lock and unlock, just SetData.</p>