The infamous socket A Sempron 2800+

[Neon]

I received a socket A Sempron 2800+ this week, which nominally operates at 12x 167MHz = 2000MHz, 1.60V. However, a careful look at this processor shows that it is fake. Some details are shown below.

[Neon]

Compare the fake label of Sempron 2800+ with the genuine label of Sempron 2400+. Note:
1. Different fonts
2. Genuine Sempron has uneven kerning in the word, "Sempron", which is not reproduced in the fake
3. Genuine Sempron has greater spacing between, "AMD" and "Sempron"
4. Genuine Sempron has better resolution in the 14x14 barcode

[Neon]

There are sets of surface trace bridges (L bridges) which control several of the crucial parameters that define the processor to the system BIOS. These bridges are not configured as expected for a Sempron 2800+, and some have been altered. I used information at Fab51 to determine the bridge configurations. It is possible to determine which processor was modified to mimic a Sempron 2800+.

There are 5 L11 bridges that define the processor VID. Next to this are the 5 L8 bridges that define VID in mobile processors using PowerNow! In desktop processors, the L8 bridges are always all closed. In mobile processors, L8 bridges have the same configuration as L11. In the fake, both L11 and L8 bridges are configured C::C: (closed, open, open, closed, open) from bottom to top. This equals 1.525V for a desktop, or 1.35V for a mobile processor.

[Neon]

There are 5 L6 bridges that define the max FID (multiplier) in mobile processors. In desktops, all L6 bridges are always closed, because they do not use these values. In the fake, L6 bridges are configured CCC:: from top to bottom. This equals 12.5x multiplier.

[Neon]

There are 5 L3 bridges that define the startup FID in desktop and mobile processors. The fake seems configured CC::C from right to left. This equals 6.0x multiplier. However, look carefully above the 3rd bridge - there is a small hole, through which the trace is pressed onto the conductive copper ground plane below. This effectively shorts (closes) the severed bridge, so the new altered configuration is CCC:C from right to left. This equals 12.0x multiplier.

There are 4 L12 bridges that define the FSB sense. Note that there are 2 different types of bridge cuts - most of the bridge cuts were made by the factory laser, and have squared ends, to make a rectangle-shaped cut. There is a second type of cut that is slightly wider, and has rounded ends, to make an oval-shaped cut. The original configuration (square cut only) was C:CC from right to left. This equals 133MHz for mobile or Geode processors. Note that the 2nd bridge is shorted in the same manner as before (see the small hole above the square cut?). The new altered configuration is CCC: from right to left. This equals 167MHz.

There are 4 L5 bridges that define the product ID. Note that there are again 2 types of bridge cuts, square and round. The original configuraton (square cut only) was CC:C from right to left. This equals Athlon XP-M. The cutting the 2nd bridge, the new altered configuration is C::C. This equals Sempron.

In summary, the bridges defined the processor in this manner:
original configuration --> altered configuration
ProductID Athlon XP-M --> Sempron
FSB 133 MHz --> 167 MHz
Startup FID 6.0x --> 12.0X
Max FID 12.5x --> 12.5x (unused in desktop)
Frequency 1667 MHz --> 2000 MHz
VID 1.35V --> 1.525V

Thus, AXMD2000FJQ3C becomes SDA2800DUT3D.