topic Re: Updating UBOs on Sandy Bridge GPUs causes visual bugs in Graphics

Updating UBOs on Sandy Bridge GPUs causes visual bugs

DK1 — Sat, 21 Mar 2015 21:06:17 GMT

What's the proper way to update UBOs on Sandy Bridge GPUs? When using OpenGL, updating the UBO using glBufferSubData without issuing a glFinish before causes image corruption. To me it seems as though the buffer update is immediate and not queued, leading to corruption of whatever object was rendering at the time. Calling glFinish before UBO update fixes the issue. Do I need to always use sync objects when dealing with UBOs? This issue is not present with my other GPUs (non-intel). I have latest drivers installed, but I noted this issue long ago.

Re: Updating UBOs on Sandy Bridge GPUs causes visual bugs

Allan_J_Intel1 — Mon, 23 Mar 2015 16:27:41 GMT

I would need more information in regards to your system configuration:

Which version of Windows do you have?

I also need the graphics driver version?

http://www.intel.com/support/graphics/sb/CS-011363.htm Graphics Drivers — Identifying Your Graphics Driver Version

Processor model:

Click the Windows icon, and then right-click Computer .

Select Properties .

Find System Type on the Properties window, and then note the processor model.

Allan.

Re: Updating UBOs on Sandy Bridge GPUs causes visual bugs

DK1 — Wed, 25 Mar 2015 10:42:49 GMT

Intel HD 3000 (Intel i5-2450M CPU)

Driver Version 15.28.23.64.4101

Problem was noted much earlier with versions 2622 and 3517.

Re: Updating UBOs on Sandy Bridge GPUs causes visual bugs

Allan_J_Intel1 — Thu, 26 Mar 2015 14:12:48 GMT

Thanks. I am forwarding this information to our engineering team.

Allan.

Re: Updating UBOs on Sandy Bridge GPUs causes visual bugs

ROBERT_U_Intel — Thu, 26 Mar 2015 15:41:33 GMT

@ kd-11

This is a known issue with the Sandybridge and as you pointed out was resolved in later GPU's. At this time there are no plans to port the resolution for the issue back to Sandybrige drivers.

Thanks

Robert

Re: Updating UBOs on Sandy Bridge GPUs causes visual bugs

DK1 — Fri, 27 Mar 2015 17:44:44 GMT

Thank you for your assistance.