Sempron 2200+ not recognized by A7V400-MX

[Jan Klaverstijn]

Hi all,

I just installed a new CPU in my Asus A7V400-MX. It was sold as an AMD
Sempron 2200+. In order to get it recognized I flashed the latest BIOS
version 1004 . However, it still tells me it sees a 900MHz cpu. I reset the
default settings after flashing to no avail. Can I cure this or am I simply
cheated when bying the cpu? I run Linux on that box. This is the content of
/proc/cpuinfo:

processor : 0
vendor_id : AuthenticAMD
cpu family : 6
model : 8
model name : AMD Athlon(tm)
stepping : 1
cpu MHz : 899.977
cache size : 256 KB
fdiv_bug : no
hlt_bug : no
f00f_bug : no
coma_bug : no
fpu : yes
fpu_exception : yes
cpuid level : 1
wp : yes
flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca
cmov pat pse36 mmx fxsr sse syscall mmxext 3dnowext 3dnow
bogomips : 1795.68


I need the additional performance badly. Please help.

Kind regards,
- Jan.

 

[dino]

have you gone in and set the FSB to 166 mhz in the BIOS?

 

[Paul]

Hi all,

I just installed a new CPU in my Asus A7V400-MX. It was sold as an AMD
Sempron 2200+. In order to get it recognized I flashed the latest BIOS
version 1004 . However, it still tells me it sees a 900MHz cpu. I reset the
default settings after flashing to no avail. Can I cure this or am I simply
cheated when bying the cpu? I run Linux on that box. This is the content of
/proc/cpuinfo:

processor : 0
vendor_id : AuthenticAMD
cpu family : 6
model : 8
model name : AMD Athlon(tm)
stepping : 1
cpu MHz : 899.977
cache size : 256 KB
fdiv_bug : no
hlt_bug : no
f00f_bug : no
coma_bug : no
fpu : yes
fpu_exception : yes
cpuid level : 1
wp : yes
flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca
cmov pat pse36 mmx fxsr sse syscall mmxext 3dnowext 3dnow
bogomips : 1795.68


I need the additional performance badly. Please help.

Kind regards,
- Jan.

According to this, it is supposed to read 1.8GHz.
http://www.tomshardware.com/cpu/20040728/sempron-01.html

With an FSB of 266, the clock should be 133. 1800MHz divided
by 133MHz gives a multiplier of 13.5 .

Have a look in the downloadable manual, as the paper manual in
the motherboard box has at least one error when it comes to
the DSW setting.

http://www.asus.com.tw/pub/ASUS/mb/socka/km400a/a7v400-mx/e1817_a7v400-mx.pdf

Make sure the DSW is set for 133MHz CPU clock, as that should
cause the FSB to run at 266, and give you a core of 1.8GHz. Since
not all the DSW settings are documented, maybe you've discovered
a way to get a 66MHz clock fed to the processor ? Since nobody has
read the numbers off the top of the clockgen chip on that board, I
cannot look up what the other dip switch settings would do.

HTH,
Paul


HTH,
Paul

 

[Driekes]

Jan,

Je moet de dipswitches op het moederbord instellen!

Kijk even ik het manual voor de instellingen.

Werner

 

[Jan klaverstijn]

According to this, it is supposed to read 1.8GHz.
http://www.tomshardware.com/cpu/20040728/sempron-01.html

With an FSB of 266, the clock should be 133. 1800MHz divided
by 133MHz gives a multiplier of 13.5 .

Have a look in the downloadable manual, as the paper manual in
the motherboard box has at least one error when it comes to
the DSW setting.

http://www.asus.com.tw/pub/ASUS/mb/socka/km400a/a7v400-mx/e1817_a7v400-mx.pdf

Make sure the DSW is set for 133MHz CPU clock, as that should
cause the FSB to run at 266, and give you a core of 1.8GHz. Since
not all the DSW settings are documented, maybe you've discovered
a way to get a 66MHz clock fed to the processor ? Since nobody has
read the numbers off the top of the clockgen chip on that board, I
cannot look up what the other dip switch settings would do.

HTH,
Paul


HTH,
Paul

Thanks for your input; it will certainly set me on the right track.

What I get from this is: I need to set the switch to a higher FSB. In
fact the Sempron has a 333MHz fsb. This suggests I set the switch to
166.67Mhz. This makes perfect sense as 166/100*900=1500, 900 being the
current reading for processor speed and knowing that a 2200+ is in
fact a 1500MHz. Bummer I missed the DSW; my "other motherboard" has no
switches or jumpers so I just didn't look. I will do this tonight
(currently I am in the office) but am confident this will make all the
difference. One tinge of doubt comes from the remark in the doc that
changing the switch settings does not make sense when the chip is
locked. What's the story here?

Thanks again,
Jan.

 

[Paul]

(e-mail address removed) (Paul) wrote in message

Thanks for your input; it will certainly set me on the right track.

What I get from this is: I need to set the switch to a higher FSB. In
fact the Sempron has a 333MHz fsb. This suggests I set the switch to
166.67Mhz. This makes perfect sense as 166/100*900=1500, 900 being the
current reading for processor speed and knowing that a 2200+ is in
fact a 1500MHz. Bummer I missed the DSW; my "other motherboard" has no
switches or jumpers so I just didn't look. I will do this tonight
(currently I am in the office) but am confident this will make all the
difference. One tinge of doubt comes from the remark in the doc that
changing the switch settings does not make sense when the chip is
locked. What's the story here?

Thanks again,
Jan.

Locking refers to the multiplier. The processor chip takes the
external clock and multiplies it by a constant that is fixed
during manufacturing.

The DSW switches control the clockgen. They modify the external
clock, and the processor has no influence over that clock signal.
Thus, the clockgen is changable via the DSW.

Overclocking can be done by either changing the external
processor clock or by changing the multiplier. AMD has been
shipping multiplier locked processors for some time, leaving
the external clock generator as the only way to modify them.
So, the DSW can be used for adjusting the processor to run at
nominal conditions, or to overclock the processor. When using
the external clock in this fashion, you may need faster memory,
or the Northbridge itself may become the limiting factor in
how fast the system runs. In addition, on some single channel
motherboards, as you raise the memory clock, you cannot run a
full set of DIMM modules, and have to reduce the number of
DIMMs used. That means external clock modifying has its limits,
and they may be related more to Northbridge or the memory bus
than to the processor itself.

HTH,
Paul

 

[Jan Klaverstijn]

Paul,

As could be expected the processor is now recognized as 1500 MHz and the
performance gain is very noticable.

gatekeeper:/usr/local/httpd/bin# cat /proc/cpuinfo
....
model name : AMD Sempron(tm) 2200+
stepping : 1
cpu MHz : 1494.004
cache size : 256 KB
....

Many thanks for the expert advice and background info, Paul. You could have
done away with two lines of RTFM comments but instead choose to patiently
elaborate. I appreciate this much, it's what makes these newsgroups work for
me.

Regards,
Jan.