25 Mar
2010
25 Mar
'10
10:20 a.m.
On Thursday 25 March 2010, at 13.32.43, David Olofson <david(a)olofson.net>
wrote:
On Thursday 25 March 2010, at 12.49.31, Ralf Mardorf
<ralf.mardorf@alice-
dsl.net> wrote:
[...]
> Btw. the
> graphics has access to the main memory, unfortunately it's a shared RAM,
> OTOH I used HPET so unwanted interrupts because of a shared RAM
> shouldn't be the cause, if I do understand the workings of HR timers
> correctly.
[...interrupts, DMA etc...]
BTW, the most common problem with graphics and realtime systems seems to be
drivers abusing PCI port blocking as a performance hack. When the command
buffer on the video card is full, the PCI bus blocks the CPU (completely - no
IRQs, no nothing), instead of the driver going to sleep and waiting for an IRQ
or some other proper solution. Might improve the 3D framerates slightly, but
kills lowlatency audio...
--
//David Olofson - Developer, Artist, Open Source Advocate
.--- Games, examples, libraries, scripting, sound, music, graphics ---.
| http://olofson.net http://kobodeluxe.com http://audiality.org |
| http://eel.olofson.net http://zeespace.net http://reologica.se |
'---------------------------------------------------------------------'