Exceeding maximum absolute voltage
 

By how much can the maximum absolute voltage of 2.3V for DDR2 DRAM
chips be exceeded? I don't intend to do it, but I have a motherboard
that lets the memoy voltage be set as high as 2.839V, and it's maker
says that's OK, although they won't guarantee against damage.

Exceeding maximum absolute voltage
 

On Fri, 17 Sep 2010 15:59:03 -0700 (PDT), "larry moe 'n curly"
wrote:

By how much can the maximum absolute voltage of 2.3V for DDR2 DRAM
chips be exceeded?

Nothing. That would be why they call it "absolute maximum" eh? Maybe you
get lucky and nothing bad *apparently* happens, maybe it goes Pffft!,
maybe it just slowly corrupts your files.

I don't intend to do it, but I have a motherboard
that lets the memoy voltage be set as high as 2.839V, and it's maker
says that's OK, although they won't guarantee against damage.

The motherboard manufacturer or the memory manufacturer? An engineering
rep or some guy in an off-shore call center?

--
Rich Webb Norfolk, VA

Exceeding maximum absolute voltage
 

larry moe 'n curly wrote:
By how much can the maximum absolute voltage of 2.3V for DDR2 DRAM
chips be exceeded? I don't intend to do it, but I have a motherboard
that lets the memoy voltage be set as high as 2.839V, and it's maker
says that's OK, although they won't guarantee against damage.


One way to get that info, is if the manufacturer writes up an
ISSCC (International Solid State Circuits Conference) paper.
Sometimes, if they've done a new semiconductor process, the
details will be given in the paper, including the "real"
absolute max (i.e. the value that killed the device in the lab,
something akin to breakdown voltage). The only time I read and
compared such a value using a paper like that, it was
about 200mV above the datasheet value, which isn't much margin
at all (and that was for a non-Intel processor).

Or, you can look in an enthusiast forum, and see what they're up
to. Some Micron D9 tested at 2.51V. Try to find a thread
where they burned some up :-)

http://www.xtremesystems.org/forums/...d.php?t=121284

Paul

Exceeding maximum absolute voltage
 

Rich Webb wrote:

On Fri, 17 Sep 2010 15:59:03 -0700 (PDT), "larry moe 'n curly"
wrote:

By how much can the maximum absolute voltage of 2.3V for DDR2 DRAM
chips be exceeded?

Nothing. That would be why they call it "absolute maximum" eh? Maybe you
get lucky and nothing bad *apparently* happens, maybe it goes Pffft!,
maybe it just slowly corrupts your files.

I don't intend to do it, but I have a motherboard
that lets the memory voltage be set as high as 2.839V, and it's maker
says that's OK, although they won't guarantee against damage.

The motherboard manufacturer or the memory manufacturer? An engineering
rep or some guy in an off-shore call center?

All the RAM chip makers and engineers who used to work for local chip
companies all agreed with you -- emphatically. It was the
motherboard maker, BioStar that said it was OK to exceed 2.3V, even
though they wouldn't guarantee against damage to the memory, and they
said the memory would very likely burn up at 2.4V. I don't think any
of those people at BioStar knew anything -- too pretentious and
authoritarian.

Exceeding maximum absolute voltage
 

On Sep 17, 8:18*pm, Paul wrote:
larry moe 'n curly wrote:

By how much can the maximum absolute voltage of 2.3V for DDR2 DRAM
chips be exceeded? *I don't intend to do it, but I have a motherboard
that lets the memoy voltage be set as high as 2.839V, and it's maker
says that's OK, although they won't guarantee against damage.

One way to get that info, is if the manufacturer writes up an
ISSCC (International Solid State Circuits Conference) paper.
Sometimes, if they've done a new semiconductor process, the
details will be given in the paper, including the "real"
absolute max (i.e. the value that killed the device in the lab,
something akin to breakdown voltage). The only time I read and
compared such a value using a paper like that, it was
about 200mV above the datasheet value, which isn't much margin
at all (and that was for a non-Intel processor).

Or, you can look in an enthusiast forum, and see what they're up
to. Some Micron D9 tested at 2.51V. Try to find a thread
where they burned some up :-)

http://www.xtremesystems.org/forums/...d.php?t=121284

* * Paul

The fine geometry MOS these days is nearly like eeprom of the dark
ages. There is a threshold shift of the fets as they are clocked. My
recollection is threshold voltages get larger over time, but don't
quote me. The shift is incorporated into the spice models (or should
be). [If the threshold increases, then the weak model.] If you
increase the voltage, you probably won't get the 10 year life for
which the process is probably specd.

Stick with Asus or Gigabyte. I'm leery of 2nd tier mobos.

Exceeding maximum absolute voltage
 

On Fri, 17 Sep 2010 15:59:03 -0700 (PDT), "larry moe 'n curly"
wrote:

By how much can the maximum absolute voltage of 2.3V for DDR2 DRAM
chips be exceeded? I don't intend to do it, but I have a motherboard
that lets the memoy voltage be set as high as 2.839V, and it's maker
says that's OK, although they won't guarantee against damage.


If they won't guarantee it, then they know it is too high. The numbers
you cite are almost 20% higher than spec.

Exceeding maximum absolute voltage
 

On Fri, 17 Sep 2010 15:59:03 -0700, larry moe 'n curly wrote:

By how much can the maximum absolute voltage of 2.3V for DDR2 DRAM
^^^^^^^^^^^^^^^^
chips be exceeded? I don't intend to do it, but I have a motherboard
that lets the memoy voltage be set as high as 2.839V, and it's maker
says that's OK, although they won't guarantee against damage.
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

Read your own question again, with emphasis as shown.

In other words, pretty much zero, if you want it to operate as
advertised.

Good Luck!
Rich

Exceeding maximum absolute voltage
 

On Sep 17, 6:59*pm, "larry moe 'n curly"
wrote:
By how much can the maximum absolute voltage of 2.3V for DDR2 DRAM
chips be exceeded? *I don't intend to do it, but I have a motherboard
that lets the memoy voltage be set as high as 2.839V, and it's maker
says that's OK, although they won't guarantee against damage.

The world may never know:

http://www.youtube.com/watch?v=Jhjb4...t=1& index=49

Exceeding maximum absolute voltage
 

Rich Grise wrote:

On Fri, 17 Sep 2010 15:59:03 -0700, larry moe 'n curly wrote:

By how much can the maximum absolute voltage of 2.3V for DDR2 DRAM
^^^^^^^^^^^^^^^^
chips be exceeded? I don't intend to do it, but I have a motherboard
that lets the memoy voltage be set as high as 2.839V, and it's maker
says that's OK, although they won't guarantee against damage.
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

Read your own question again, with emphasis as shown.

In other words, pretty much zero, if you want it to operate as
advertised.

The motherboard manufacturer, BioStar, wouldn't guarantee against
damage even if I never exceeded the chip maker's maximum absolute of
2.3V, nor would they guarantee that the voltage applied to the memory
would never go above that by itself, such as because of a glitch.

Exceeding maximum absolute voltage
 

"larry moe 'n curly" wrote in news:a6b3aff5-
:

BioStar that said it was OK to exceed 2.3V, even
though they wouldn't guarantee against damage to the memory, and they
said the memory would very likely burn up at 2.4V. I don't think any
of those people at BioStar knew anything -- too pretentious and
authoritarian.



Actually I think they just mean that you're welcome to try. They tell you
what they think is right, but they're quite happy to let people thrash test
at their own expense and blog about it. After all, what better publicity can
there be for them? Beats any possible claim they could make for themselves.
When they tell you they think it will burn up at n.nn volts, they're just
giving you fair warning.

These days, a piece of string is as long as a million tech-happy bloggers say
it is, so long as enough of them form a consensus about it.