Register Guidelines E-Books Search Today's Posts Mark Forums Read

Go Back   MobileRead Forums > E-Book Readers > More E-Book Readers > iRex > iRex Developer's Corner

Notices

Reply
 
Thread Tools Search this Thread
Old 02-28-2007, 11:45 PM   #1
joblack
Wizard
joblack ought to be getting tired of karma fortunes by now.joblack ought to be getting tired of karma fortunes by now.joblack ought to be getting tired of karma fortunes by now.joblack ought to be getting tired of karma fortunes by now.joblack ought to be getting tired of karma fortunes by now.joblack ought to be getting tired of karma fortunes by now.joblack ought to be getting tired of karma fortunes by now.joblack ought to be getting tired of karma fortunes by now.joblack ought to be getting tired of karma fortunes by now.joblack ought to be getting tired of karma fortunes by now.joblack ought to be getting tired of karma fortunes by now.
 
Posts: 1,256
Karma: 1418786
Join Date: Jul 2006
Location: Somewhere on earth
Device: Kindle Paperwhite, Kindle DX, JBC, Onyx M92
overclock or change cpu?

I´ve read about the XScale Cpu (http://www.intel.com/design/network/...pp/ixc1100.htm)

Have somebody checked out if it is possible to overclock the actual cpu or change it to the higher version (533 MhZ)?

Is the CPU removable or hard wired? It should boost the speed of the device (but decrease battery life) ....

Greetings
joblack is offline   Reply With Quote
Old 03-01-2007, 09:41 AM   #2
mike b
Member
mike b began at the beginning.
 
Posts: 16
Karma: 10
Join Date: Jan 2007
Underclock to save power?

By the same token, is it possible to underclock the CPU to save power and extend battery life?
mike b is offline   Reply With Quote
 
Enthusiast
Old 03-01-2007, 12:15 PM   #3
Adam B.
Addicted to Porting
Adam B. is a jewel in the roughAdam B. is a jewel in the roughAdam B. is a jewel in the roughAdam B. is a jewel in the roughAdam B. is a jewel in the roughAdam B. is a jewel in the roughAdam B. is a jewel in the roughAdam B. is a jewel in the roughAdam B. is a jewel in the roughAdam B. is a jewel in the roughAdam B. is a jewel in the rough
 
Adam B.'s Avatar
 
Posts: 1,695
Karma: 7194
Join Date: Oct 2006
Location: Indianapolis, IN
Device: iRex iLiad, Nokia 770, Samsung i760
It should be possible to both overclock, and underclock the xscale cpu. I think iRex had made a post somewhere about underlocking it to 33mhz between page turns to maximize battery life.

I'm sure if you want to overclock it, you would have to do it yourself (or wait for someone else to figure it out). But it should all be able to be done via software.
Adam B. is offline   Reply With Quote
Old 03-01-2007, 12:25 PM   #4
BKeeper
Groupie
BKeeper will become famous soon enoughBKeeper will become famous soon enoughBKeeper will become famous soon enoughBKeeper will become famous soon enoughBKeeper will become famous soon enoughBKeeper will become famous soon enoughBKeeper will become famous soon enough
 
BKeeper's Avatar
 
Posts: 174
Karma: 728
Join Date: Jul 2006
Device: Cybook, iPad
@mike b
Yes it is!
That's exactly what iRex is supposedly trying to implement.
(and since hard suspend mode is not possible, it's also the only choice... ;-)
behold, at last the promised 15h. . . . .
BKeeper is offline   Reply With Quote
Old 03-02-2007, 03:00 AM   #5
narve
iLiad fan
narve can teach chickens to fly.narve can teach chickens to fly.narve can teach chickens to fly.narve can teach chickens to fly.narve can teach chickens to fly.narve can teach chickens to fly.narve can teach chickens to fly.narve can teach chickens to fly.narve can teach chickens to fly.narve can teach chickens to fly.narve can teach chickens to fly.
 
Posts: 210
Karma: 3864
Join Date: Oct 2006
Device: iRex iLiad
Quote:
Originally Posted by BKeeper
@mike b
Yes it is!
That's exactly what iRex is supposedly trying to implement.
(and since hard suspend mode is not possible, it's also the only choice... ;-)
behold, at last the promised 15h. . . . .
Except the 15 hours are for another model...
narve is offline   Reply With Quote
Old 11-10-2007, 12:41 PM   #6
kurifu
Junior Member
kurifu began at the beginning.
 
Posts: 9
Karma: 10
Join Date: Nov 2007
Device: iLiad
Based on this info:

http://en.wikipedia.org/wiki/Xscale#...Processor_Line

Looks like 400MHz (PXA255) is end of the line for the PXA25x processor series, so while I suspect it could be over clocked, it doesn't look like you would be able to change out the processor unless you wanted to downgrade (probably not beneficial either since the 255 seems to addressed a lot of issue with higher power consumption from the previous PXA25x models.)

The PXA26x might be similar in architecture, though it comes in a different package, I don't know for sure.

The PXA27x appears to be too different to use.
kurifu is offline   Reply With Quote
Old 11-11-2007, 12:27 AM   #7
jharker
Developer
jharker could sell banana peel slippers to a Deveel.jharker could sell banana peel slippers to a Deveel.jharker could sell banana peel slippers to a Deveel.jharker could sell banana peel slippers to a Deveel.jharker could sell banana peel slippers to a Deveel.jharker could sell banana peel slippers to a Deveel.jharker could sell banana peel slippers to a Deveel.jharker could sell banana peel slippers to a Deveel.jharker could sell banana peel slippers to a Deveel.jharker could sell banana peel slippers to a Deveel.jharker could sell banana peel slippers to a Deveel.
 
Posts: 345
Karma: 3473
Join Date: Apr 2007
Location: Brooklyn, NY, USA
Device: iRex iLiad v1, Blackberry Tour, Kindle DX, iPad.
Rincewind's original "powersave" ipdf implemented exactly this kind of CPU underclocking to save power.

Before releasing any "official" CPU scaling for the iLiad, iRex had to solve several kernel driver instability problems. These were eventually resolved.

The latest official iRex iLiad software version 2.11 scales the CPU speed to save power all the time. The CPU scaling is (I believe) handled by the PowerMgr program.

In contrast, Rincewind's powersave ipdf provided power conservation only when the pdf viewer was running (of course).

I don't know what the lowest stable speed is. Rincewind's ipdf went down to 100 MHz. It's possible that the official iRex work takes it down to 33 MHz, but I don't know what it actually does.

Edit: Oh, silly me, the most recent post was a necro post. Most of this thread dates from a long time ago.
jharker is offline   Reply With Quote
Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Slow -- excessive cpu utilization Ozzy Calibre 23 02-15-2011 11:55 AM
Calibre 0.6.50 using 100% cpu sol_barbez Calibre 10 06-14-2010 10:33 PM
is it possible to make calibre just use one CPU? booksonthemove Calibre 1 02-20-2010 04:55 PM
iLiad ipdf with CPU Throttling yokos iRex Developer's Corner 61 08-26-2008 07:10 PM
Screen vs CPU vs Battery Life Colin Dunstan Lounge 5 02-17-2005 01:23 AM


All times are GMT -4. The time now is 05:26 AM.


MobileRead.com is a privately owned, operated and funded community.