Hi,<br><br><div class="gmail_quote">2011/8/24 Alex Deucher <span dir="ltr"><<a href="mailto:alexdeucher@gmail.com">alexdeucher@gmail.com</a>></span><br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;"> <div class="im">On Wed, Aug 24, 2011 at 2:14 AM, Chen Jie <<a href="mailto:chenj@lemote.com">chenj@lemote.com</a>> wrote:<br> > Hi,<br> ><br> > 2011/8/23 Alex Deucher <<a href="mailto:alexdeucher@gmail.com">alexdeucher@gmail.com</a>><br> >><br> >> > Not sure I understand it or not, but we're using the sideport way, and<br> >> > has a dedicated 128M DDR2 memory as VRAM.<br> >><br> >> The default behavior of the system bios is to set up sideport memory<br> >> interleaved with stolen system memory. Unless your bios only enables<br> >> sideport you'll need to respect the stolen system memory used as vram.<br> >> Also, sideport memory has really limited memory bandwidth. It's a<br> >> powersaving feature as if you un-interleave the sideport memory, you<br> >> can put the display in sideport and stop memory access via the CPU.<br> >> For decent performance, you need to use system memory or interleaved<br> >> sideport and system memory.<br> > Got it, thanks.<br> > BTW, if using 128M sideport memory, will it occupy another 128M system<br> > memory in the default behavior?<br> ><br> <br> </div>Yes. Normally the sbios reports a slightly smaller ram size to<br> account for the stolen memory or marks it as reserved so the OS<br> doesn't try and use it.</blockquote><div>We've checked the sbios setup code -- the setup logic is borrowed from coreboot, and is confirmed using the single memory channel mode.</div><div><br></div><div><br></div> <div><br></div><div>Regards,</div><div>-- Chen Jie</div></div>