Thanks very much to Maxim and Loren! MmWriteCombined is exactly what was
needed. The DPC now works just as fast as the app. The MS documentation of
this option is - well, nonexistant if you ask me! I saw the option but
since I wasn’t writing a real “video port driver” I figured it was
something too specialized. Thanks again!
Paul Braun
The concept of write combining is described in books and papers on PCI bus and
on x86 CPUs.
It allows the north bridge chip to coalesce writes to video memory and then
execute them all in a PCI/AGP burst, which is by far (around 4 times) faster
then one-by-one.
Maxim Shatskih, Windows DDK MVP
StorageCraft Corporation
xxxxx@storagecraft.com
http://www.storagecraft.com
----- Original Message -----
From: “Paul Braun”
To: “Windows System Software Devs Interest List”
Sent: Friday, October 03, 2003 7:10 PM
Subject: [ntdev] Re: Writing to Overlay from DPC…success!
> Thanks very much to Maxim and Loren! MmWriteCombined is exactly what was
> needed. The DPC now works just as fast as the app. The MS documentation of
> this option is - well, nonexistant if you ask me! I saw the option but
> since I wasn’t writing a real “video port driver” I figured it was
> something too specialized. Thanks again!
>
> Paul Braun
>
> —
> Questions? First check the Kernel Driver FAQ at
http://www.osronline.com/article.cfm?id=256
>
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