Geode NX, Core Voltage
The core voltage of the Geode NX processor cannot be correctly detected. About why it is.
This page is being written based on Geode NX, and Athlon XP-M is also applicable.
Core Voltage
AMD Geode NX Processor has a very low core voltage. However, it cannot be correctly recognized with a general mother board.
Therefore, you should set the core voltage by using the BIOS menu etc.
However, the rated voltage might not be able to be selected.
Enlarge image of GeodeNX1500
Enlarge image of GeodeNX1750
| OPN | Package | V_CORE | FSB | T_Die | notes | ||
| Geode NX TDP 25W | |||||||
| 1400MHz | ANXS1750FXC3S | OPGA | 1.25 | 266 | 95 | - | |
| ANXS1750FXC3M | OPGA | 1.25 | 266 | 95 | RoHS | ||
| Geode NX TDP 9W | |||||||
| 1000MHz | ANXL1500FGC3S | OPGA | 1.00 | 266 | 95 | - | |
| ANXL1500FGC3M | OPGA | 1.00 | 266 | 95 | RoHS | ||
| 667MHz | ANXL1250FYC3S | OPGA | 1.10 | 266 | 95 | - | |
| ANXL1250FYC3M | OPGA | 1.10 | 266 | 95 | RoHS | ||
The core voltage is output according to the VID[4:0] code of CPU. In a general mother board, the definition of this VID code is the voltage for Desktop CPU. Therefore, even if Mobile CPU is used, it is always considered the VID for Desktop CPU.
As a result, the core voltage that is higher than a normal voltage will be supplied to the Geode NX and Athlon XP-M.
| CPU | V_CORE | VID[4:0] | |
| Rated voltage | Detected voltage | ||
| Products | VID for Mobile | VID for Desktop | code |
| Geode NX 1750 | 1.250V | 1.425V | 10001 |
| Geode NX 1500 | 1.000V | 1.175V | 11011 |
| Geode NX 1250 | 1.100V | 1.275V | 10111 |
| Athlon XP-M 2600 | 1.450V | 1.575V | 01011 |
Thermal Power
It is written in Geode NX1750 as "AMD Geode NX 1750@14W Processor".
The 14W shows Typical Power. Maximum Power of NX 1750 is 25W.
| CPU | Frequency | V_CORE | Thermal Power | T_Die | ||
| Working State C0 | Stop Grant C3/S1 | |||||
| Maximum | Typical | |||||
| Geode NX 1750 ANXS1750FXC3S | 1400MHz | 1.250V | 25.0W | 14.0W | 3.0W | 95 |
| Geode NX 1500 ANXL1500FGC3S | 1000MHz | 1.000V | 9.0W | 6.0W | 3.0W | 95 |
| Geode NX 1250 ANXL1250FYC3S | 667MHz | 1.100V | 9.0W | 6.0W | 3.0W | 95 |
| Athlon XP-M 2600 AXMG2600FQQ4C | 2000MHz | 1.450V | 47.0W | - | - | 100 |
Valid Voltage and Frequency
In the Geode NX 1750, the following operation frequencies and the voltages are officially supported.
| CPU | Geode NX Voltage and Frequency Combinations | |||||
| V_CORE | ||||||
| 1.25V | 1.20V | 1.15V | 1.10V | 1.05V | 1.00V | |
| Geode NX 1750 | 1400MHz | 1200MHz | 1133MHz | 1067MHz | 1000MHz | - |
| Geode NX 1500 | - | - | - | - | - | 1000MHz |
| Multiplier(FSB 266) | 10.5X | 9.0X | 8.5X | 8.0X | 7.5X | |
| Multiplier(FSB 333) | 8.5X(1417) | 7.5X(1250) | 7.0X(1167) | 6.5X(1083) | 6.0X(1000) | |
The column of FSB 333 is a reference value. It is not ratings.
As for a dynamic voltage change, hardware and BIOS of the mother board should correspond to it. However, there is maybe no ATX mother board corresponding to Geode NX.
In the Laptop and the Notebooks, the dynamic voltage change by the softwares might be possible.
Please refer to
CrystalCPUID or
CPUMSR
SOFTVID[4:0] and VID[4:0] Code to Voltage Definition
The difference of VID code for the Mobile and for the desktop is shown below.
| V_CORE (V) | VID | |
| Mobile | Desktop | [4:0] |
| Athlon XP-M - | Athlon XP Sempron | L11 |
| 2.000 | 1.850 | 00000 |
| 1.950 | 1.825 | 00001 |
| 1.900 | 1.800(N) | 00010 |
| 1.850 | 1.775 | 00011 |
| 1.800 | 1.750(M) | 00100 |
| 1.750 | 1.725 | 00101 |
| 1.700 | 1.700(P) | 00110 |
| 1.650 | 1.675 | 00111 |
| 1.600 | 1.650(K) | 01000 |
| 1.550 | 1.625 | 01001 |
| 1.500(L) | 1.600(U) | 01010 |
| 1.450(Q) | 1.575 | 01011 |
| 1.400(V) | 1.550(H) | 01100 |
| 1.350(J) | 1.525 | 01101 |
| 1.300(W) | 1.500(L) | 01110 |
| - | 1.475 | 01111 |
| V_CORE (V) | VID | |
| Mobile | Desktop | [4:0] |
| Geode NX Athlon XP-M | - | L11 |
| 1.275 | 1.450 | 10000 |
| 1.250(X) | 1.425 | 10001 |
| 1.225 | 1.400 | 10010 |
| 1.200(T) | 1.375 | 10011 |
| 1.175 | 1.350 | 10100 |
| 1.150(C) | 1.325 | 10101 |
| 1.125 | 1.300 | 10110 |
| 1.100(Y) | 1.275 | 10111 |
| 1.075 | 1.250 | 11000 |
| 1.050 | 1.225 | 11001 |
| 1.025 | 1.200 | 11010 |
| 1.000(G) | 1.175 | 11011 |
| 0.975 | 1.150 | 11100 |
| 0.950 | 1.125 | 11101 |
| 0.925 | 1.100 | 11110 |
| - | - | 11111 |
ID=0 is connected to GND.
ID=1 opens.
To set the original VID
If the mother board doesn't have the voltage changing function, it is possible to change the voltage by adding the switch to the VID[4:0] pins of the Core Voltage regulator. In addition, it is necessary to cut the VID signal that CPU outputs.
Appendix
Socket A Pin Descriptions
reference
- Created on 04/15/2005
