Frequently asked questions
theme: Desktop Athlon XP Multiplier Adjustments on the fly from Windows
31th December FAQ:
Q: I do not understand your article, could you please explain to me
how...
A: For starters: This article is about software controlled multiplier
change. What you set in BIOS is hardware controlled multiplier change
and it has nothing to do with this - software controlled doesn't depend
on whether your motherboard is able to change multiplier in BIOS or (via
DIP switches), whether you use wire tricks or not. Hardware controlled
change works only at startup, software controlled works anytime, even
from Windows. Software controlled is pure internal change inside the
processor itself. No pins are affected by this. But for software
controlled change there are some requirements that has to be met. First
the processor must have some MSR registers enabled and those registers
are disabled for desktop parts. You have to use regular mobile CPU or to
modify your desktop part to mobile. To do this, connect one bridge on L5
on processor package. It is the second from right on Thoroughbred and
Barton cores, the second from left on Palomino and Morgan cores. Second,
chipset on your motherboard has to support software controlled change (eg.
support PowerNow!) and the chipset has to be configured properly by
BIOS. If your chipset doesn't support PowerNow!, there is no change it
will work. If it does support it but is badly configured, then you have
to adjust chipset settings by a program called WPCREDIT. On majority of
motherboards however, this is not necessary.
Q: I heard L6 bridges change multiplier on mobile CPUs.
A: Wrong. L6 bridges define maximum multiplier you can set by software
change. It is a upper limit multiplier, the highest value any software
can force your CPU to transition to.
Q: When I click on "Set" button to change multiplier, system freezes
or restarts.
A: This is because your chipset doesn't support PowerNow! or it is badly
configured. In second case, some WPCREDIT changes will be required.
Q: Will this work on nForce 2 motherboards?
A: We don't know yet. There were some reports it does work on nForce 2
but majority of people say it doesn't. Especially Abit NF7 users
complain it freezes system. Maybe some WPCREDIT changes will help us.
Now I can say it doesn't work on nForce 2 and maybe it will with some
luck.
Q: Your program doesn't work for me. Screenshot from CPUMSR looks like this:
A: This means you didn't turned your CPU into mobile one. On this screenshot see Frequency adjustments: Not Supported. This happens when L5 bridge is not connected or is not connected good enough. In order to enable missing MSR registers, you have to see here Supported. That however, doesn't mean it will work on your system - chipset has to support software controlled change.
Q: CPUMSR tells voltage is 2.00V. But it isn't !
A: The program will just tell you what processor requires through
SoftVID pins. If your motherboard has SoftVID pins connected then
motherboard should be running at that voltage. If not then this info is
of no use for you.
Q: I am using Windows 98 and multiplier change doesn't work. But in
Windows 2000 / XP it does.
A: I am aware of this problem. I am trying to find reason why it is not
working on Windows 98. But I do not have Windows 98 what makes this task
little difficult.
Q: Will it be possible for motherboard manufacturers to implement
software controlled change into BIOS?
A: Sure. It would be quite easy since some motherboards do already do
software controlled change to set maximum (L6) multiplier when they
detect mobile CPU (that is why some motherboards loads OS at L6 settings
- if they do, then BIOS used software change immediately after
initialization).
29th and 30th December FAQ:
Q: I can't change voltage, why?
A: Voltage set by software is signaled to SoftVID pins that are
different from VID pins. VID pins are used as startup voltage (or just
voltage on desktop parts). Required motherboard circuits for VID are
implemented on all systems but as for SoftVID they are usually present only
on mobile systems. So when you change voltage by software, Lo (no
voltage) / Hi (voltage) status changes at SoftVID pins. But because
those are not connected on desktop motherboards to voltage regulator,
nothing happens.
Q: Which of Athlon (K7) class processor cores can support on-the-fly
multiplier adjustments?
A: Palomino, Morgan, Thoroughbred, Barton and also Applebred and Thorton
(those last two are just Thoroughbred / Barton with disabled part of L2
cache).
Q: How can I turn my Athlon XP / MP on Palomino core (Model 6 - CPUID
066x) or Duron on Morgan core (Model 7 - CPUID 067x) to mobile one?
A: Just connect the second bridge from dot on L5 (located near L8 and
L11):
Q: What do L6 bridges do?
A: They set maximum multiplier that can be chosen by software. When
setting multiplier by software processor checks whether required
multiplier is not higher than L6 settings. If it is, it sets L6 settings
instead. By adjusting L6 settings you can set this maximum as you want.
Q: What multiplier will the processor boot at?
A: In all cases, processor will start at L3 settings (startup
multiplier). However, AMD wants notebook systems to load OS at maximum
frequency, therefore BIOS on mobile systems is required to do software
controlled transition to highest multiplier (that is to do P-State
transition) immediately after initialization. On desktop systems, there
can be two scenarios. The first one is that the BIOS does
not do P-State transition. In that case processor will load OS at L3
settings. The second scenario is that BIOS program is somewhat
"mobile-like" and it will transition CPU to maximum multiplier - that is
to L6 settings. This this second scenario you can't just cut all
L6 (that would give you 24x multiplier) but instead you have to cut L6
to a multiplier your CPU can handle at startup.
Q: What voltage will the processor boot at?
A: If your motherboard doesn't have SoftVID pins connected, it will boot
at VID settings (that is L11 settings). If it has SoftVID pins
connected, then the answer is the same as for multiplier.
Q: Will this work for "super locked" CPUs (processors produced after
39th week of 2003)?
A: Probably not because those processors do not seem to depend on
bridges at all. Moding L3 bridges had no effect for those so I do not
expect moding L5 would. But maybe...Some people say it works for those also and after changing them
to mobile they are able to change multiplier by software! This was
confirmed by many people now (as of 31th December).
Q: Will you make a utility like PowerNow! driver that would lower
multiplier at idle and return it to maximum under full load?
A: Yes! I have an idea how could this work and we will make such a
utility. It is just only a question of time.