What is Write Combining, And why does turning it off make my system freeze?

Question

I've had issues the last few days with my windows XP SP3 system freezing up- I eventually worked out it started after i messed with display settings, and turned off write combining. Freezes often occured RIGHT after the log in screen, though sometimes i got the system running up to half an hour before it froze. I had this issue in VGA mode, safe mode with networking, and standard boots, while, thankfully, standard safe mode worked.

So, my question is, what is write combining, and why would turning it off cause display freezes?

The system is a thinkpad r61, with a intel x3100 graphics card.

Answer 1

Wikipedia reference: http://en.wikipedia.org/wiki/Write_combining. Basically it's a technique whereby devices that support burst mode writing can reduce the number of physical write operations, thereby improving performance. In the context of Windows XP, most commonly associated with display hardware.

Oddly, disabling write combining is often recommended for display freezing issues, not enabling it. Which makes sense: usually something that increases performance does so at the cost of stability. Sorry, I've got nothing for you on the second part of your question.