Gary
Mon May 17 14:50:36 CDT 2004
That's not entirely correct. DirectDraw and hardware acceleration are not
the same thing.
You can add hardware acceleration for GDI operations such as pattern fills,
line drawing, blitting, etc. which will greatly improve RDP performance.
For example, if you compare the Permedia 3 driver, the TVIA driver, and the
flat driver on the same CEPC, you will see significant RDP performance
differences running Winbench over RDP. The differences between the drivers
is primarily in what they accelerate in hardware.
If you look in the sample shipped source for the TVIA, you'll see that in
the BltPrepare the driver determines whether or not the operation can be
done in hardware and replaces the function pointer with a pointer which uses
the hardware if it can be done.
This is by no means a complete list, just a list of operations which from my
research i've found that can make a difference with RDP performance.
BitBlt with a sourcecopy rop
MaskBlt with an AAF0 ROP
Patblt with a solid color
Patblt with an F0 rop
PatBlt with a 5A rop
PatBlt with a 55 rop
BitBlt with a B8 rop
horizontal and vertical lines
BitBlt with an 88 rop
If you're seeing performance issues, you can use dispperf to see what
operations are being hit the most in the display driver, from there you can
determine whether or not the operation is going to hardware, an EMUL
function, or the generic blitting function. The generic blitting function
is slow, so if you have a significant number of operations going to that,
then you should look into adding an EMUL function to accelerate the most
important operations if hardware cannot be used.
Hope that helps.
Gary Daniels
Windows CE GDI Test
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"sergeir" <anonymous@discussions.microsoft.com> wrote in message
news:886501c4326d$bece1f20$a301280a@phx.gbl...
> Thank you, Steve, for explanations. We are loosing
> customers who are not satisfied with RDP performance with
> their applications running in terminal server mode on our
> CE-powered devices ( some process control idustrial
> application, which draw a lot of diagrams continiously).
>
> So, based on what you have written, one could make the
> following conclusion ( correct me if I am wrong) : if you
> are going to make and sell Thin Client devices, do not
> bother to add to it any hardware accelerating features as
> well as any DirectDraw , DirectX etc features to your
> platform in PB, since they will just eat up device space
> and make no asset to RDP.
>
> As for RDP and CE, we were told by the lost potential
> customer, that unlike RDP the Citrix ICA uses not just
> bitmaps but some graphic primitives so that speeds up
> perfromance slightly, and Sun Ray is yet a lot better in
> that sense so they would go with that.
>
> Best regards
> Sergei
>
> >-----Original Message-----
> >Well, yes of course it's going to be slow as the hardware
> acceleration isn't
> >actually used in either case. The RDP implementation
> cannot assume
> >DirectDraw is available on the CE device. Plus the RDP
> protocols are
> >actually platform independent. and thus make no
> assumption of the
> >availability of DirectDraw. The display information from
> the remote machine
> >is simply packaged up and sent over the network to the
> terminal for display.
> >This is true of a windows XP system running RDP
> connecting to another
> >Windows XP system and is unrelated to CE in particular.
> >
> >--
> >Steve Maillet (eMVP)
> >EmbeddedFusion
> >smaillet_AT_EmbeddedFusion_DOT_com
> >
> >
> >.
> >