Klaus,
I would be interested to learn why Nokia chose the TI OMAP1710
processor. I assume it was because of its integral DSP support as well
as support for multiple comms interfaces
UTC has a new mobile phone/PDA manufactured by UTS marketed in the US
as the 6700 by both Sprint and Verizon and running WM 5.0 PPC version.
It has a much smaller screen size than the N770 but it is still very
useable as a PDA. It seems quite fast and the graphics are excellent
including video. In terms of comms interfaces it has three radios and
it supports CDMA voice, EVDO broadband and 1xRTT data, 802.11b,
bluetooth, infrared, and USB. I have been surprised by how responsive
this device appears to be, especially since it has the more feature
rich PPC version of Windows Mobile and not the stripped down mobile
phone version. I do not know if it has an onboard DSP chip. Here are
the specs:
Specifications
Operating System Windows Mobile 5.0
Processor Type Intel PXA 270 Processor
Processor Speed 416 MHz
Memory 64MB SDRAM, 128MB ROM
Display Type 2.8" Color TFT Touch Screen
Display Resolution 240 x 320
Dimensions 4.25" x 2.3" x 1"
Weight 6.07 oz.
Battery , Type: Removable 1350 mAh Lithium-lon
Built-in Expansions 1.3 Megapixel cameraCamcorderBluetoothWi-FiMini
SD Expansion Slot
Add-on Expansions N/A
Synchronization Included: Mini USB Port
[EMAIL PROTECTED] wrote:
Am 20 Feb 2006 um 11:08 hat Clemens Eisserer geschrieben:
Yes I ment UI responsivness, not raw graphic performance.
The whole UI simply feels a bit sluggish compared to Palms or
Pocket-PCs, I know they have faster CPUs but i also think their
software simply is more efficient.
I don't think that there will be a huge speed improvement. Why?
1) The N770 has just a 16-bit data bus but it has to draw the whole GUI to a 800x480 16 bit
pixel memory buffer. This is much more than the 320x320 pixels on a palm!
2) As far as I understand the OMAP doc, the LCD redraw had also be done using the 16-bit
memory data path. If its done at 60 Hz (I don't know), there is a constant memory dma at
800x480x60 = 21,97 MWords/sec blocking the bus. In fact the OMAP has a shared memory
design!
3) The bus is shared with the ARM cpu core and the DSP cpu core. Of course, there are
caches, but you can't cache everything.
3) As often said, gtk+2 is very good, but not the fastest. I compiled some demos with fltk, and
I *feel* that they run faster. But it too late to change the main gui lib and fltk has other
disadvantages.
4) The memory design: The N770 is more or less just a Linux device and uses a lot of
libraries. Most of the libs are designed for a linux desktop machine, where memory is
(because of swap) not a problem. This is maybe the biggest problem for Linux based PDAs!
One has to fine tune all those libs to perform better on small devices, which would be a big
task and maybe also force a development split, so the folks at Nokia must maintain those
libs. There is no manpower for that.
It would be interessting, how a 128 MB RAM N770 would perform. I think 128 MB-DDR-RAM
is the limit for the build in OMAP processor.
Don't get me wrong: I like the N770 (especially the bright display!), and I even don't think that
it is too slow. I compare it with my Sharp Zaurus and most times the N770 wins. The 800
pixel display is a huge plus working with gnumeric.
Please correct my if there are some facts wrong, I *really* would like to hear that! I got most
of this reading the OMAP5912 Design Overview, which should be similar to the OMAP1710
used in the N770 device.
CU, -Klaus
|
