High memory voltage on Phenom...

[saaya]

@BadNizze & Lightman: 9500 needs more time.

why would a 9500 need more time than a 9600? that doesnt make any sense...
It sounds more like some cpus die quicker than others...

I killed these CPUs on both the MSI and Gigabyte boards.

so first you killed it on one and then you killed it again on another board? ^^ hehehe

1.344V or so on the CPU, 2.38~2.42V on the memory voltage, NB speed around 2000, and the key it appears is that I was using the 1066 setting and clocking up from that point. This has occurred with a couple of other people. AMD is looking at one of the dead CPUs at this time, but they continue to advise us not to run memory voltages above 2.2V for any length of time.

is this 2.2v vdimm max official or unofficial?

The good news is my 0744 9600 has not died after a week of trying to kill it, but I have noticed a little degradation in memory performance now. It could be I had a couple of weaker than normal CPUs (understand the last production batch is really strong). The main reason for the potential kill problem is something we will discuss shortly.

http://www.jedec.org/

Memory is kinda loosey goosey ... there is a consortium organization, whose membership of course includes most all the major memory makers as well as Intel, AMD, nVidia etc. You can find the JEDEC standards for DDR2 memory at that web site.

The voltage for JEDEC standardized DDR2 is 1.8+/-0.1 Volts for DDR2-800, as I recall (and I may be wrong), JEDEC never ratified any specs for memory above this speed... for DDR2 anyway.

Anand has summarized the JEDEC specs for DDR2/DDR3 in this article:
http://www.anandtech.com/printarticle.aspx?i=2989

This of course does not stop memory makers from trying to woowooo your wallet with promises of faster memory or lower latency but outside of the standards -- you will commonly find low latency DDR2 but speced out at 2.0 or higher volts (operating voltage). nVidia even skirts this by the SPD to store special 'overclocked' settings for the memory used in it's SLI certified memory brand.

Nonetheless, Phenom, with the IMC, was likely built to withstand x% above and beyond the JEDEC spec, however it appears that limit is at or below 2.2 volts... so if you are looking for 1067 memory, or even low latency DDR2-800 ... pay attention to the voltage spec.

i would rather say jedec is extremely slow at doing anything at all and they are sucking up so much to everybody they cannot possibly agree on anything usefull as somebody might not like it. hence jedec specs and what mfgs and customers are REALLY running their memory at are moving further away from each other day by day. thanks to jedec not getting their job done we now have epp, xmp and amds version of epp/xmp... hooray!

and all this because jedec couldnt agree to implement a voltage option in the spd spec. cause in the end thats all epp xmp and amds epp/xmp are about. they enable high speed memory by allowing higher vdimm than default.

I believe this is related to CMOS latch-up. Then I think that the circuit design to protect from latch-up increase the input capacitance (and then reduce frequency response). I think phenom work well with low voltage memory because they have reduce protection and then associate parasitics. The drawback is you have to respect absolute maximum ratings.

wha?

Though, I have had a blown AMD processor in the past that they rejected the RMA for overclocking (which I did not overclock, I was not happy).

unless you mentioned you oced it or the cpu had clear signs from ocing thats very very unlikely. i worked for amd tech support and i cant imagine rmas being refused because of "ocing" when the cpu had never been oced or overvolted.