Yet another bulging-capacitors replacement

"Arfa Daily" <arfa.daily_at_ntlworld.com> wrote in
news:Q_Xeo.1360$c_6.370_at_newsfe30.ams2:



"Jeff Liebermann" <jeffl_at_cruzio.com> wrote in message
news:phnn76d5fjpcls7lfscj6t40hehqnc9db4_at_4ax.com...
On Mon, 30 Aug 2010 05:35:00 -0400, JW <none_at_dev.null> wrote:

On Fri, 27 Aug 2010 20:19:44 -0700 Jeff Liebermann <jeffl_at_cruzio.com
wrote in Message id: <ebug76lk13plippid57h6q6vacu8ve4om9_at_4ax.com>:

I don't believe it. The winner of the power hogging consumer CPU
contest was the DEC/Intel Alpha 21364 (EV79):
http://en.wikipedia.org/wiki/Alpha_21364
which burned 155 watts. Itanium II came close with 130 watts (per
core).

Check again.
http://ark.intel.com/Product.aspx?id=43410&processor=9350&spec-codes=S
LBMX 185W! Gotta love that price as well.

I stand corrected.
http://techreport.com/discussions.x/18445
Some of the reader comments are rather interesting. Still, with any
of these "powerful" processors, a conventional air cooled machine is
going to have a very hot breath and a rather large power supply. I
just don't see this kind of power dissipation in a "dedicated game
machine". Measuring the AC mains power consumption should settle the
matter.

--
Jeff Liebermann jeffl_at_cruzio.com


Have you any idea just how much processing power it takes to run a
user-interactive story in real time, and then to 3D render the
graphics in real time ? Do you think that they rate the 12v PSU for
23.5 amps in one version, and 32 amps in the other, for fun ? Those
are not real questions, because I know full well when you stop and
think about it, you know the answers, Jeff.

I've just looked at the rating plate on the bottom of one of the
cases, and it is 240v (nominal UK line voltage) at 1.8 amps. I make
that a maximum input power of around 430 watts. It's a switching PSU,
so I reckon that we can rate that as being at the very worst 80%
efficient, so that's still 345 watts potentially going somewhere. I'm
prepared to go with 45 watts into ancillary circuitry on the board,
which still leaves around 300 watts going somewhere.

that assumes that all the power of the supply is actually used.
I'm sure there is some reserve capacity there.

"max input power" is not "actual used power".

On Tue, 31 Aug 2010 01:26:23 +0100, "Arfa Daily"
arfa.daily_at_ntlworld.com> wrote:

Have you any idea just how much processing power it takes to run a
user-interactive story in real time, and then to 3D render the graphics in
real time ?

Well, no. I'm not a power user. What little rendering I do is with
bacon fat.

Do you think that they rate the 12v PSU for 23.5 amps in one
version, and 32 amps in the other, for fun ? Those are not real questions,
because I know full well when you stop and think about it, you know the
answers, Jeff.

Actually, I don't know. I don't have any customers with such machines
and have had zero experience with high power graphic workstations
(other than early 1980's Applicon CAD stations) or game machines. I
have worked on various network servers, which do burn such power
levels. I have looked at a 3D MRI image processor, which had some
manner of dedicated processor inside, but it certainly wasn't belching
400 watts of heat (my estimate by the amount of fan noise).

I've just looked at the rating plate on the bottom of one of the cases,
and
it is 240v (nominal UK line voltage) at 1.8 amps. I make that a maximum
input power of around 430 watts. It's a switching PSU, so I reckon that we
can rate that as being at the very worst 80% efficient, so that's still
345
watts potentially going somewhere. I'm prepared to go with 45 watts into
ancillary circuitry on the board, which still leaves around 300 watts
going
somewhere. Perhaps I'm being naive, but my best guess is that it's
disappearing into the two bloody great BGAs which the manufacturers are
trying their utmost to heatsink. If you try to run one of these machines
with the heatsinking not in place, it goes into thermal protect in about 5
seconds - and all it's doing then is booting. The heatplates on the BGAs
are
at this point hot enough to take your fingerprints off ...

Nope, I'm pretty sure that these two puppies are good for 150 watts
apiece,
when the machine is doing some real work.

Ok, I stand corrected. I've been assuming that the CPU's are doing
most of the power dissipation. I didn't think of a dedicated graphics
processor or whatever the BGA chips are doing. Do you have a gun
style IR thermometer? I use that to determine if anything is running
hot. I use a black (non-reflective) cardboard tube attached to the
lens to prevent it from picking up adjacent components. Incidentally,
I have yet to find one where the laser dot actually points to where
the device is measuring when in close proximity. You can also get a
rough idea of how much effort is going into cooling. If the BGA's
burn more power than the CPU's, then they're going to need more
massive heat sinks and better air cooling. At 400 watts, I would
think they would have gone to heat pipes and external radiators or
maybe liquid cooling.

Incidentally, I repaired a P4 motherboard yesterday which used Artic
Silver. My guess is that there was about 5 times as much Artic Silver
smeared over the CPU (and down the sides where it does nothing) as
necessary. The stuff down the sides was still fluid, so at $10 for
3.5 grams, I saved the excess.


--
Jeff Liebermann jeffl_at_cruzio.com
Skype: JeffLiebermann AE6KS 831-336-2558

On Tue, 31 Aug 2010 09:35:11 -0700, Jeff Liebermann wrote:

ncidentally, I repaired a P4 motherboard yesterday which used Artic
Silver. My guess is that there was about 5 times as much Artic Silver
smeared over the CPU (and down the sides where it does nothing) as
necessary. The stuff down the sides was still fluid, so at $10 for 3.5
grams, I saved the excess.

Heh...reminds me of a previously repaired (not by me) QSC PLX series amp
I opened up and scraped about a pound of white paste out of it.

On Tue, 31 Aug 2010 16:56:37 +0000 (UTC) Meat Plow <mhywatt_at_yahoo.com
wrote in Message id:
pan.2010.08.31.16.56.27_at_hahahahahahahah.nutz.I.am>:

On Tue, 31 Aug 2010 09:35:11 -0700, Jeff Liebermann wrote:

ncidentally, I repaired a P4 motherboard yesterday which used Artic
Silver. My guess is that there was about 5 times as much Artic Silver
smeared over the CPU (and down the sides where it does nothing) as
necessary. The stuff down the sides was still fluid, so at $10 for
3.5 grams, I saved the excess.

Heh...reminds me of a previously repaired (not by me) QSC PLX series amp
I opened up and scraped about a pound of white paste out of it.

You sure that someone hadn't left their marshmallows in there?

Well Jim, that was why I used the word "potentially", but judging by the
size of the pins used to couple the power supply's output into the board -
if you've been following the thread, you will recall that I previously
described them as being of the size you would find on the line cord for a
kettle - then I wouldn't say that there was too much in the way of reserve.

All of the processing power is in those two BGAs Jeff.
(...)

That's a LOT of processing power, needing a lot of amps to perform ...

The fan on these things *is* large, as is the heatsinking assembly, and when
the processor finally decides to ramp the fan up, it sounds like a vacuum
cleaner. For this reason, at idle they tend to run it at below what I would
consider a 'sensible' minimum, exacerbating the thermal stresses on the
chips, their (lead-free) soldering, and the board to which they are
attached.

Arfa Daily wrote:

Well Jim, that was why I used the word "potentially", but judging by the
size of the pins used to couple the power supply's output into the
board -
if you've been following the thread, you will recall that I previously
described them as being of the size you would find on the line cord for a
kettle - then I wouldn't say that there was too much in the way of
reserve.


"The size you would find on the line cord for a kettle" doesn't have
much meaning in the US. :)


--

"Michael A. Terrell" ?mike.terrell_at_earthlink.net? wrote in message
news:m5ednfqzQtE_8ePRnZ2dnUVZ_qWdnZ2d_at_earthlink.com...
?
? Arfa Daily wrote:
??
?? Well Jim, that was why I used the word "potentially", but judging by the
?? size of the pins used to couple the power supply's output into the
?? board -
?? if you've been following the thread, you will recall that I previously
?? described them as being of the size you would find on the line cord for a
?? kettle - then I wouldn't say that there was too much in the way of
?? reserve.
?
? "The size you would find on the line cord for a kettle" doesn't have
? much meaning in the US. :)

Why is that ? You have electric kettles in your kitchens - I've used them.

Or don't you call them kettles ?. OK, anyway, if it's a better description,
the size of the round ground pin on a line cord that has a three pin plug.
Is that more meaningful ? 3/16" diameter maybe ? 4mm ?

Arfa Daily wrote:

"Michael A. Terrell" ?mike.terrell_at_earthlink.net? wrote in message
news:m5ednfqzQtE_8ePRnZ2dnUVZ_qWdnZ2d_at_earthlink.com... ?
? Arfa Daily wrote:
??
?? Well Jim, that was why I used the word "potentially", but judging by
the ?? size of the pins used to couple the power supply's output into
the ?? board -
?? if you've been following the thread, you will recall that I
previously ?? described them as being of the size you would find on the
line cord for a ?? kettle - then I wouldn't say that there was too much
in the way of ?? reserve.
?
? "The size you would find on the line cord for a kettle" doesn't have
? much meaning in the US. :)

Why is that ? You have electric kettles in your kitchens - I've used
them.


I've never seen one. Even Coffee pots are rare these days.


Or don't you call them kettles ?. OK, anyway, if it's a better
description, the size of the round ground pin on a line cord that has a
three pin plug. Is that more meaningful ? 3/16" diameter maybe ? 4mm ?


3/16" is between AWG 5 & AWG 4. 4 mm is between AWG 7 & AWG 6. How
much current do those kettles draw?

On Wed, 01 Sep 2010 16:55:34 -0400, Michael A. Terrell wrote:

Arfa Daily wrote:

"Michael A. Terrell" ?mike.terrell_at_earthlink.net? wrote in message
news:m5ednfqzQtE_8ePRnZ2dnUVZ_qWdnZ2d_at_earthlink.com... ?
? Arfa Daily wrote:
??
?? Well Jim, that was why I used the word "potentially", but judging by
the ?? size of the pins used to couple the power supply's output into
the ?? board -
?? if you've been following the thread, you will recall that I
previously ?? described them as being of the size you would find on the
line cord for a ?? kettle - then I wouldn't say that there was too much
in the way of ?? reserve.
?
? "The size you would find on the line cord for a kettle" doesn't have
? much meaning in the US. :)

Why is that ? You have electric kettles in your kitchens - I've used
them.


I've never seen one. Even Coffee pots are rare these days.


Or don't you call them kettles ?. OK, anyway, if it's a better
description, the size of the round ground pin on a line cord that has a
three pin plug. Is that more meaningful ? 3/16" diameter maybe ? 4mm ?


3/16" is between AWG 5& AWG 4. 4 mm is between AWG 7& AWG 6. How
much current do those kettles draw?

Half what a US kettle would draw?



A good British 240Vac kettle will take 3KW, yes 3KW. No waiting 10

Arfa Daily wrote:

"Michael A. Terrell" ?mike.terrell_at_earthlink.net? wrote in message
news:m5ednfqzQtE_8ePRnZ2dnUVZ_qWdnZ2d_at_earthlink.com...
?
? Arfa Daily wrote:
??
?? Well Jim, that was why I used the word "potentially", but judging by
the
?? size of the pins used to couple the power supply's output into the
?? board -
?? if you've been following the thread, you will recall that I previously
?? described them as being of the size you would find on the line cord
for a
?? kettle - then I wouldn't say that there was too much in the way of
?? reserve.
?
? "The size you would find on the line cord for a kettle" doesn't have
? much meaning in the US. :)

Why is that ? You have electric kettles in your kitchens - I've used
them.


I've never seen one. Even Coffee pots are rare these days.


Or don't you call them kettles ?. OK, anyway, if it's a better
description,
the size of the round ground pin on a line cord that has a three pin
plug.
Is that more meaningful ? 3/16" diameter maybe ? 4mm ?


3/16" is between AWG 5 & AWG 4. 4 mm is between AWG 7 & AWG 6. How
much current do those kettles draw?


--

On Wed, 1 Sep 2010 02:40:53 +0100, "Arfa Daily"
arfa.daily_at_ntlworld.com> wrote:

All of the processing power is in those two BGAs Jeff.
(...)

Thanks for the details. I really don't know anything about such
dedicated game machines. I just assumed that all such machines used
common processors to make development easier.

That's a LOT of processing power, needing a lot of amps to perform ...

I found the Kill-o-watt meter and stuffed it in line with my Dell
Optiplex 960 (E8500 3.2Ghz). 43 watts at idle, 70 watts max when
playing a DVD (not including LCD monitor). Speedfan 4.40 says 31C for
both CPU cores after about an hour. The one large fan is barely
spinning and very quiet (which is why I bought this one). When I set
the fan to run full speed, it's quite loud.

The fan on these things *is* large, as is the heatsinking assembly, and
when
the processor finally decides to ramp the fan up, it sounds like a vacuum
cleaner. For this reason, at idle they tend to run it at below what I
would
consider a 'sensible' minimum, exacerbating the thermal stresses on the
chips, their (lead-free) soldering, and the board to which they are
attached.

Well, theory suggests that the life of a semiconductor device is
greatly affected by the number of thermal cycles it experiences
(thermal fatigue). I don't know if this also applies to CPU's or
whatever is in those BGA chips (FPGA/GPU?), but might be something
else to worry about. I would guess(tm) that the large aluminum heat
sink would moderate any abrupt changes in temperature, thus making it
less of a concern. However, that might not be the case for the solder
balls supporting the BGA.



--
Jeff Liebermann jeffl_at_cruzio.com

Just as a matter of interest Meat, what is your preferred brand and type of
heatsink goop when working with these very high power processors?

I have always
resisted using this stuff, because it's so messy, and so hard to remove
unless you use the complementary cleaner

, but if it really is that much more
effective

I don't believe it. The winner of the power hogging consumer CPU
contest was the DEC/Intel Alpha 21364 (EV79):

Why is that ? You have electric kettles in your kitchens - I've used them.