Unlocked XP-M

Is it possible to tell for how long the XP-M's are going to be unlocked?

Why is it only 2400+ and 2600+ that are unlocked?


Morgan O.

On Tue, 21 Dec 2004 09:14:26 GMT, Morgan Ohlson
wrote:

Is it possible to tell for how long the XP-M's are going to be unlocked?

No

Why is it only 2400+ and 2600+ that are unlocked?

All XP-M's are factory unlocked, the later the date code the better
[probability] overclock.

Show me the 2400/2600 XP-M that is locked !

Morgan O.

AFAIK (as far as I know) the XPM will always be unlocked, since laptops
change the multiplier (and voltage?) on the fly to save the battery.


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On Tue, 21 Dec 2004 15:24:56 -0800, Ed Light wrote:

AFAIK (as far as I know) the XPM will always be unlocked, since laptops
change the multiplier (and voltage?) on the fly to save the battery.

That is the kind of answer that is very much appreciated.

The kinds that explains why... Understanding is a blessing.


Morgan O.

Ed Light wrote:
AFAIK (as far as I know) the XPM will always be unlocked, since
laptops change the multiplier (and voltage?) on the fly to save the
battery.

It depends entirely on your definition of "unlocked".

Athlons (both XP's and 64's) actually have two multiplier settings, the
startup and maximum multiplier. These are encoded in the L3 and L6 bridges
respectively. The startup multiplier is the one the CPU uses on power-on,
and the maximum multiplier sets the maximum multiplier that can be set
through PowerNow. All K7 desktop motherboards do multiplier adjustment
through the BP_FID pins, which override the L3 bridge setting and
effectively set the startup multiplier. This startup multiplier is not
(ironically) limited to the maximum multiplier. What AMD has done on the
desktop chips is make it so that the startup multiplier cannot be changed.
This means that the motherboard multiplier settings (or bridge/pin
modifications for that matter) will do nothing. However, "mobile" systems
adjust the multiplier on the fly through PowerNow, which is limited to the
range specified by the maximum multiplier. "Desktop" chips have PowerNow
disabled, so the startup multiplier is what the chip will always run at.

AMD can move both the L3 and L6 into the core so that they are factory-set
without affecting the operation of PowerNow (since all that will do is make
the available range fixed, not make the multiplier unadjustable). So what
AMD cannot do is remove PowerNow from mobile chips. Should AMD do this (stop
the modification of the startup and maximum multis), the mobile chips will
only operate at their stock default multiplier in boards that do not support
PowerNow. In other words, ALL AthlonXP's (mobile or desktop) will only
operate at their stock startup multiplier NF1/NF2 boards (which do not
support PowerNow), though would still have a downwards-adjustable multiplier
(exactly like the Athlon 64's) on other boards. In fact, the A64's operate
in exactly the same way as the K7's (startup/maximum multiplier), but with
the L3 and L6 bridges inside the core (so unchangable). However, all K8
chipsets support PowerNow, and this is how the multiplier changes are done
through the BIOS. The FX series just have a maximum PowerNow multiplier of
24x (as opposed the the "unlocked" AXP's where the startup multiplier is
adjusted).

For my definition of unlocked, I would like to say that lockedness (or
otherwise) should be a property of the chip. You should be able to change
motherboards, and the chip will not become locked (or unlocked). The
exception to this is boards that do not have multiplier adjustment
capabilities. Another requirement that would be nice is that the lockedness
of the chip remains the same regardless of the modifications done to it.
It's a property of the chip set at the factory, sort of. This leads on to
the inevitable conclusion that lockedness is a function of available
equipment, skills, knowledge and time. For example, the Palomino chips are
"locked" in any definition of the word if you don't want to play with the
bridges. However, should you have the equipment/skills/time to join the L1
bridges, then I would say that the modified chip is now unlocked, and hence
by the second assumption, the chip was unlocked to begin with. Similarly, I
would say that given a hundred million dollars of equipment (MBE machines
and the like), a decent sized workforce and a year or two to work on the
problem (and possibly throw in a low-level schematic or similar obtained
through industrial espionage from a corrupt AMD employee), it would be
possible to undo to lock on the recent chips (though obviously not
particularily economical).

The definition I like is that the chip is unlocked if you can (chip
limitations notwithstanding) change the configuration parameters of the
chip. A configuration parameter being defined as something that restricts
how the chip may be used. For example:
1) The current multiplier is not a configuration parameter (it can be
changed through PowerNow)
2) The startup multiplier is a configuration parameter
3) The voltage is not a configuration parameter (it's just a suggestion to
the motherboard as to what to give the chip)

Since there are 5 configuration parameters for the AXP chips (startup
multiplier, maximum multiplier, PowerNow capability, SMP capability, L2
cache size), each of these needs to be specified for a given amount of
equipment/etc. This gives (in the order given above):

Definitions:
[] Nothing: You take the chip out of the box and put it in the board. Or
possibly someone else with more experience does that for you What can you
change by messing around with BIOS & jumpers?
[] Bridge modifications: You have a conductive pen (and associated stuff)
and know how to use it.
[] 3rd-party bridge modifications: You know someone who has a conductive pen
and knows how to use it. They mess around with it and give it back to you.
What can you change by messing around with BIOS & jumpers?
[] Pin modifications: You don't want to damage the chip so restrict yourself
to painting pins or doing the wire-in-socket thing.

Palomino:
[] Nothing: NNNNN
[] Bridge modifications: YYYYY
[] 3rd-party bridge modifications: YNNNY
[] Pin modifications: YNNNN

TBred A/B and Bartons, pre week-39 or mobiles:
[] Nothing: YNNNN
[] Bridge modifications: YYYYY
[] 3rd-party bridge modifications: YNNNY
[] Pin modifications: YNNNN


TBred A/B and Bartons, post week-39 desktops:
[] Nothing: NNNNN
[] Bridge modifications: NYYYN
[] 3rd-party bridge modifications: NNNNN
[] Pin modifications: NNNNN

K8's:
[] Nothing: NNNNN
[] Bridge modifications: N/A
[] 3rd-party bridge modifications: N/A
[] Pin modifications: NNNNN

AMD could, if they wanted, make K7's the same as the K8's (ie: NNNNN for all
options) without affecting the use of PowerNow. But this would give
overclockers a real knock, as they would be stuck at the stock multiplier on
their favourite chipset (NF2).

PS: Yes, PowerNow also can do voltage changes on the fly, but this requires
motherboard support which I have not seen in any desktop boards (and
worringly is missing from some el-cheapo laptops too ...)

--
Michael Brown
www.emboss.co.nz : OOS/RSI software and more
Add michael@ to emboss.co.nz - My inbox is always open

Thanks, Michael, for your user guide!


--
Ed Light

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MS Smiley :-\

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