Clarification On Omap3430 ?


bnolsen

Member
Joined
Jan 12, 2008
Messages
107
Don't mean to be flame bait but I found this comment on an olpc wiki about the OMAP3430:

QUOTE
Have you considered the Texas Instruments OMAP3430 ARM Cortex-A8 based processors? While they do lack x86 compatability, they possess a significant number of features that make them appealing in low power deployments. (lkcl: people who have used these processors in mobile phones are now lamenting the fact. the general consensus is instead of wasting time with low-clock-rate "special dedicated blocks", just get a faster more general-purpose CPU).


What's up with lkcl ? Is it true that cell phone manufacturers are "lamenting" this chipset? Or some axe to grind here? Not like the OLPC's processor is that advanced or even tries to save power...

Also is it too late to look at including the Cortex-A9? Does silicon even exist yet for it?
 

Pickle

Mega GP Mania
Joined
May 30, 2006
Messages
5,507
Location
Detroit, Michigan
Website
Visit site
bnolsen said:
Don't mean to be flame bait but I found this comment on an olpc wiki about the OMAP3430:

QUOTE
Have you considered the Texas Instruments OMAP3430 ARM Cortex-A8 based processors? While they do lack x86 compatability, they possess a significant number of features that make them appealing in low power deployments. (lkcl: people who have used these processors in mobile phones are now lamenting the fact. the general consensus is instead of wasting time with low-clock-rate "special dedicated blocks", just get a faster more general-purpose CPU).
What's up with lkcl ? Is it true that cell phone manufacturers are "lamenting" this chipset? Or some axe to grind here? Not like the OLPC's processor is that advanced or even tries to save power...

Also is it too late to look at including the Cortex-A9? Does silicon even exist yet for it?


I believe dev test kits are available, Squidge has posted numbers from a setup which I believe represents what the pandora will be using.

The quote sounds more like an opinion than necessarily fact.
 
Last edited by a moderator:

MWeston

Internal Development
Joined
Jun 23, 2006
Messages
1,256
Location
Canada
Website
openpandora.ca
Unfortunately, this is the power of the internet. One goof says something and everyone takes it as gospel. :rolleyes:

First off, the OLPC is not a UMPC and so it isn't practical to use such a power conservative SOC when you can strap a giant battery on the back (plus the x86 compatibility they NEED if they ever hope to sell any of those). There are a lot of clocks and power domains in OMAP processors and it takes some smarts to program it over a "general-purpose CPU" and it might be more work than some companies are prepared to deal with in order to squeeze out every minute of battery life in a cell phone (which is stupid since it's a cell phone and battery life is pretty damn important).

It is very unlikely that this lkcl knows anyone using the OMAP3 in a cell phone and is probably referring to the older OMAP1710 in smart phones which is outdated by todays standards. I'm not sure of any cell phones using the OMAP24xx chip either, but I'd be anxious to read about any that do if someone knows of them.

Cortex-A9 was just recently announced by ARM. It isn't likely to see it integrated into fully tested SOC's ready for production until 2010.
 

bnolsen

Member
Joined
Jan 12, 2008
Messages
107
MWeston said:
First off, the OLPC is not a UMPC and so it isn't practical to use such a power conservative SOC when you can strap a giant battery on the back (plus the x86 compatibility they NEED if they ever hope to sell any of those). There are a lot of clocks and power domains in OMAP processors and it takes some smarts to program it over a "general-purpose CPU" and it might be more work than some companies are prepared to deal with in order to squeeze out every minute of battery life in a cell phone (which is stupid since it's a cell phone and battery life is pretty damn important).

If running a general purpose multi tasking OS like linux with several apps running at once isn't it reasonable for the OS to essentially "hide" all of these clocks and power domains ?

One thing you mentioned that I'm painfully aware of is this artificial tether to x86 which I believe is mostly the product of Microsoft's command economy. It's a shame because of all those man centuries spent on optimizing trash instruction sets. I'd love to get an inexpensive sub notebook for portable development that doesn't introduce 3rd degree burns and would be cheaper than today's current batch of systems.

Also if an omap were driven by a huge battery like in the OLPC how long would one charge go? I'm guessing it would effectively allow once a day charging only even with constant use.
 
Last edited by a moderator:

Exophase

Nothing good will ever come of Exophase.
Joined
Sep 21, 2006
Messages
10,308
Age
37
Location
Cleveland OH
The OLPC's Geode CPU is not all that bad I guess... it has a pretty good single precision FPU (that can do out of order execution with register renaming) but it's a scalar CPU that can't pair integer or load/store code. Clock for clock I expect Cortex-A8 to be much better at integer code (like most of what's written for ARM already) and probably about the same for FPU (who needs out of order and register renaming when you have 32 floating point registers anyway), and better at SIMD (NEON > MMX or 3DNow!).. and Pandora will have a significantly higher initial clock rate.

One interesting thing about Geode is that it has 2D acceleration that mops the floor with GP2X's, including blits with rotation and alpha blending, all on the CPU. If you factor in the gaming controls on the OLPC you have a device that might actually be better for games than GP2X (if there's a way to put it in tablet mode w/o turning off backlighting and color anyway). Not that it's really a good comparison.

bnolsen; x86 isn't as bad as a lot of people say it is, sure it's not ARM but then again, what is... x86-64 in particular is quite "okay", if you want trash go look at 6502.
 

bnolsen

Member
Joined
Jan 12, 2008
Messages
107
So do you have any idea of how the price of an AMD Geode compares to the price of the OMAP3430? I'm guessing it isn't exactly apples to apples.
 

Exophase

Nothing good will ever come of Exophase.
Joined
Sep 21, 2006
Messages
10,308
Age
37
Location
Cleveland OH
icurafu said:
bnolsen said:
So do you have any idea of how the price of an AMD Geode compares to the price of the OMAP3430? I'm guessing it isn't exactly apples to apples.
Judging by the cost of the everun, I would say.... "more"


Judging by the cost of OLPC I would say "less"

Much less.
 
Last edited by a moderator:

Xmas

Member
Joined
Sep 24, 2007
Messages
112
MWeston said:
I'm not sure of any cell phones using the OMAP24xx chip either, but I'd be anxious to read about any that do if someone knows of them.

There is a whole bunch of japanese DoCoMo phones (different manufacturers, starting with the 902i series) using 2420 or 2430. In western markets OMAP2420 is mainly used by Nokia: E90, N82, N93, N95 (as well as N800 and N810). But there's also a 2420 in the Moto Z8.
 
Last edited by a moderator:
Top