Copper heat spreaders for RAM: worthwhile or a waste of money?

I've managed to fry some PC3200 GB DIMM's in the past by giving them 2.9V
(on an NF7s v2.0). I think the NF7s v2.0 overvolts VDIMM (at least according
to speedfan, Sisoft Sandra and the BIOS). Would adding copper heat spreaders
make any difference over the stock AL ones? What about adding some sort of
thermal paste between the individual RAM chips and the heat spreader?

--
Doug

"pigdos" <> wrote in message news:spLJf.58355$. com...
> I've managed to fry some PC3200 GB DIMM's in the past by giving them 2.9V
> (on an NF7s v2.0). I think the NF7s v2.0 overvolts VDIMM (at least according
> to speedfan, Sisoft Sandra and the BIOS). Would adding copper heat spreaders
> make any difference over the stock AL ones? What about adding some sort of
> thermal paste between the individual RAM chips and the heat spreader?

The amount of voltage dimms can handle depends on what chips
are used, e.g. Samsung TCCD's should never be run over 2.8V,
while BH-5's and BH-6's can easily handle 3.3V or even more.
This is regardless of whether and what kind of heat spreaders
are installed.

If you've got decent airflow over your dimms, heat spreaders
accomplish nothing except to act as insulators, and make the
chips run hotter than they otherwise would. They're a marketing
gimmick and are useful only in rare cases.

On Sat, 18 Feb 2006 20:26:00 +0000, pigdos wrote:

> I've managed to fry some PC3200 GB DIMM's in the past by giving them 2.9V
> (on an NF7s v2.0). I think the NF7s v2.0 overvolts VDIMM (at least according
> to speedfan, Sisoft Sandra and the BIOS). Would adding copper heat spreaders
> make any difference over the stock AL ones? What about adding some sort of
> thermal paste between the individual RAM chips and the heat spreader?

As mark said, the heat spreaders do more harm thana good in most cases. If
you are dtermined to use them, make sure you use some thermal compound and
they fit flush on the ram.

--
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After what you and Mark said (thanks for the info as well Mark), maybe I
should just remove the heat spreaders altogether? My real problem is now
wondering if the VDIMM voltages that are reported are actual. If I set my
Nf7s v2.0 to 2.7V VDIMM, the sensors indicate 2.79V to 2.8V. If I set my
VDIMM to 2.8V, the sensors report nearly 2.9V. A patriot tech support rep.
told me that with their
PEP1G3200LL (1Gig extreme low-latency PC3200) you should never go over 2.8V.
Yet the only way I can get this RAM stable at ANYTHING over 200Mhz is to use
2.8V VDIMM (which the on-board sensors are picking up as ~2.9V).

--
Doug
"Wes Newell" <> wrote in message
news:fUPJf.2987$6f2.1099@trnddc02...
> On Sat, 18 Feb 2006 20:26:00 +0000, pigdos wrote:
>
>> I've managed to fry some PC3200 GB DIMM's in the past by giving them 2.9V
>> (on an NF7s v2.0). I think the NF7s v2.0 overvolts VDIMM (at least
>> according
>> to speedfan, Sisoft Sandra and the BIOS). Would adding copper heat
>> spreaders
>> make any difference over the stock AL ones? What about adding some sort
>> of
>> thermal paste between the individual RAM chips and the heat spreader?
>
> As mark said, the heat spreaders do more harm thana good in most cases. If
> you are dtermined to use them, make sure you use some thermal compound and
> they fit flush on the ram.
>
> --
> Want the ultimate in free OTA SD/HDTV Recorder? http://mythtv.org
> http://mysettopbox.tv/knoppmyth.html Usenet alt.video.ptv.mythtv
> My server http://wesnewell.no-ip.com/cpu.php
>

"pigdos" <> wrote in message news:x5TJf.58461$. com...
> After what you and Mark said (thanks for the info as well Mark), maybe I
> should just remove the heat spreaders altogether? My real problem is now
> wondering if the VDIMM voltages that are reported are actual. If I set my
> Nf7s v2.0 to 2.7V VDIMM, the sensors indicate 2.79V to 2.8V. If I set my
> VDIMM to 2.8V, the sensors report nearly 2.9V. A patriot tech support rep.
> told me that with their
> PEP1G3200LL (1Gig extreme low-latency PC3200) you should never go over 2.8V.
> Yet the only way I can get this RAM stable at ANYTHING over 200Mhz is to use
> 2.8V VDIMM (which the on-board sensors are picking up as ~2.9V).

First step is to see if Patriot can tell you what kind of chips are used
in those dimms. Then do some research and find out what the upper
voltage limits are for those chips.

If Patriot can't or won't tell you this info, it's a judgment call whether
you want to void your warranty and remove the spreaders.

As for the difference between set vs. sensor readings, it's safer to
assume the sensors are correct.

If one removes the memory heat spreaders, and stop air flow around
memory chips (that's a stretch), one would find that some memory chips
consistently get warmer than the others. As I recall the chips
handling the least significant bits get warmer than the MSB. I may
have this switched backwards though. The primary reason is because of
the bus default level (what it floats to) when reading and writing 8
or 16 bit data instead of 32 bit data (full bus width). That is, a "0"
and a "1" don't generate the same amount of heat in a memory chip.

Also, the average value of all bits is much closer to zero than it is
one - in both the address space and in the data space.

Notice that they are not called "heat sinks". They are called "heat
spreaders". This is appropriate because some chips are getting warmer
than others. Heat spreaders reduce localized heating.

Forrest

Motherboard Help By HAL web site:
http://home.comcast.net/~mobo.help/


On Sat, 18 Feb 2006 20:26:00 GMT, "pigdos" <> wrote:

>I've managed to fry some PC3200 GB DIMM's in the past by giving them 2.9V
>(on an NF7s v2.0). I think the NF7s v2.0 overvolts VDIMM (at least according
>to speedfan, Sisoft Sandra and the BIOS). Would adding copper heat spreaders
>make any difference over the stock AL ones? What about adding some sort of
>thermal paste between the individual RAM chips and the heat spreader?

LSb's getting warmer than MSb's (b is for bit, big B is for Byte)? LOL, this
is the most ridiculous crap I've ever heard. Do you have any proof of this
statement? There's all kinds of data stored in memory that are NOT integer
data. There's floating point data, bit masks, compressed audio/video data,
lookup tables, code etc. and none of these data types would tend to have
their least significant bits on more than their MSb's. Even for integer data
I don't even think it's that easy. What if I use chars or shorts to store
small integers instead of longs or ulongs?

Your idea about: "the average value of all bits is much closer to zero than
it is one - in both the address space and in the data space" is interesting
though. Are you saying that since most of the memory space of modern systems
is unused most of the time, that the average of all bits in the system would
be closer to zero than one?

From what I've read here and other places it seems like clip-on, RAM
heatspreaders are more for looks than anything else.


Doug
"- HAL9000" <> wrote in message
news:...
> If one removes the memory heat spreaders, and stop air flow around
> memory chips (that's a stretch), one would find that some memory chips
> consistently get warmer than the others. As I recall the chips
> handling the least significant bits get warmer than the MSB. I may
> have this switched backwards though. The primary reason is because of
> the bus default level (what it floats to) when reading and writing 8
> or 16 bit data instead of 32 bit data (full bus width). That is, a "0"
> and a "1" don't generate the same amount of heat in a memory chip.
>
> Also, the average value of all bits is much closer to zero than it is
> one - in both the address space and in the data space.
>
> Notice that they are not called "heat sinks". They are called "heat
> spreaders". This is appropriate because some chips are getting warmer
> than others. Heat spreaders reduce localized heating.
>
> Forrest
>
> Motherboard Help By HAL web site:
> http://home.comcast.net/~mobo.help/
>
>
> On Sat, 18 Feb 2006 20:26:00 GMT, "pigdos" <> wrote:
>
>>I've managed to fry some PC3200 GB DIMM's in the past by giving them 2.9V
>>(on an NF7s v2.0). I think the NF7s v2.0 overvolts VDIMM (at least
>>according
>>to speedfan, Sisoft Sandra and the BIOS). Would adding copper heat
>>spreaders
>>make any difference over the stock AL ones? What about adding some sort of
>>thermal paste between the individual RAM chips and the heat spreader?
>
>

On Tue, 21 Feb 2006 00:54:55 +0000, pigdos wrote:

> From what I've read here and other places it seems like clip-on, RAM
> heatspreaders are more for looks than anything else.
>
The manufacurer of the pc3700 ram I use discourages the use of heat
spreaders saying most do more harm than good. There are however some good
ones, but they will have fins on them and they must be installed properly
to function properly. And the means good contact and thermal compound. it
usually also means you'll be limited to one stick of ram per every 2 slots.:-)

--
Want the ultimate in free OTA SD/HDTV Recorder? http://mythtv.org
http://mysettopbox.tv/knoppmyth.html Usenet alt.video.ptv.mythtv
My server http://wesnewell.no-ip.com/cpu.php

Sure, heat spreaders.

Forrest

Motherboard Help By HAL web site:
http://home.comcast.net/~mobo.help/


On Tue, 21 Feb 2006 00:54:55 GMT, "pigdos" <> wrote:

>LSb's getting warmer than MSb's (b is for bit, big B is for Byte)? LOL, this
>is the most ridiculous crap I've ever heard. Do you have any proof of this
>statement?
< snip >

On Sun, 19 Feb 2006 05:10:53 GMT, "pigdos" <> wrote:

>After what you and Mark said (thanks for the info as well Mark), maybe I
>should just remove the heat spreaders altogether? My real problem is now
>wondering if the VDIMM voltages that are reported are actual. If I set my
>Nf7s v2.0 to 2.7V VDIMM, the sensors indicate 2.79V to 2.8V. If I set my
>VDIMM to 2.8V, the sensors report nearly 2.9V. A patriot tech support rep.
>told me that with their
>PEP1G3200LL (1Gig extreme low-latency PC3200) you should never go over 2.8V.
>Yet the only way I can get this RAM stable at ANYTHING over 200Mhz is to use
>2.8V VDIMM (which the on-board sensors are picking up as ~2.9V).
>

PC3200 does mean 200MHz memory clock rate, so what did you
expect... a miracle? Unless the manufacturer's specifications include
recommended alternate timing settings for the clock rates at which you
wish to run and you then manually set these timings in BIOS. No such
specification alternatives - no guarantee at any clock rate in excess
of 200MHz. Lacking any such higher clock-rate specs, your only hope
is to set CL to a higher value and/or set the command rate to 2T
instead of 1T and hope for the best while running memtest86 for at
least 8 hours. Trying to meet YOUR clock-specs just with a higher
voltage and no timing changes is likely to just fry the memory
devices.

How about using memory sticks genuinely spec'd for the maximum clock
rate you are ever likely to use, with latency specs (at that speed) to
your taste and then running them at the manufacturer's spec'd voltage?

Grrr... some people buy a Pinto, then expect Corvette performance.

John Lewis