AMD pin identification and function - socket 754

TStep

Platinum Member
Feb 16, 2003
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Due to a trading mishap that I don't wish to pursue in detail via the cpu forum, I've received a processor back from a previous sale that is missing two pins on the corner opposite the orientation arrow. From the AMD Data Sheet these pins are:

AH29 and AJ28

The descriptions are: VLDTO_B and Key0

I installed the mangled cpu in an Epox 8KDA3J mobo and it boots into windows and seems to function normally, however I'm concerned about long term stability. From the data sheet, I imagine the VLDTO_B pin is a redundant voltage pin for the Hypertransport functions of the processor. I can't find the KEY0 description though.

Can anyone shed some light on the function of these pins and any adverse effects that may arise from them not being involved in the cpu circuitry loop.

TIA
-Tom
 

Joepublic2

Golden Member
Jan 22, 2005
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It's called Key0, and it's right next to the corner, as is the key1 pin... It might just be there for mechanical reasons, such as not putting the cpu in the wrong way.
 

Vegitto

Diamond Member
May 3, 2005
5,234
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Key0 is for not misplacing, VLDTO_B is for voltage or grounding I believe. May cause some sort of instability. I'd Prime for a while if I were you.
 

TStep

Platinum Member
Feb 16, 2003
2,460
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Thanks, I kind of figured a KEY pin was just a physical place marker.
 

Zap

Elite Member
Oct 13, 1999
22,377
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Originally posted by: TStep
Thanks, I kind of figured a KEY pin was just a physical place marker.

Most likely. I've seen CPUs missing voltage and ground pins that still ran fine at stock. There was this s478 P4 3.4GHz that was missing two pins - person tried installing the CPU when it was oriented wrong and couldn't figure out why it didn't sit in the socket properly. Even smashed it down with the HSF and then tried running it. CPU still worked and passed a few hours of Prime. One was voltage, one ground pin.