Re: Asus P5K Premium with Xeon E5472 and 771 to 775 adapter sticker??

[Bob F]

Bob F wrote:
> Not exactly an overclock yet, but maybe??
>
> I am considering buying a used E5472 processor to use in this P5K
> Premium board with a 771 to 775 adapter sticker. My memory is a pair
> of 2GB PC2-6400 samsung M3 78T5663EH3-cf7. This processor has a 1600
> MHz FSB. The motherboard seems to be
> speced for 1600 FSB.
>
> Does anyone have any knowledge or opinions about this kind of
> project? Is it likely to work? Will it overclock?

I finally got around to trying this processor on the P5K Premium after my
problems on the Abit IP35 Pro.

I modded the ASUS AMI bios using the following:
http://www.delidded.com/how-to-update-cpu-microcode-in-ami-bios/

Booted it up to bios, reset to default, rebooted to windows. Windows runs for
awhile, then crashes. That's way further than I got with the Abit board.

Speedfan seems to display temps about 15C below the real temp displayed by
coretemp on the E5472. It was right on with my Q8200.

Temps, still using the stock Intel heatsink, seem to be higher than they should
be, so maybe that is why it crashes. The E5472 seems to have a max temp spec of
75C. Speedfan was showing temps in the mid 60's, so with the 15C offset, maybe
too high. The E5472 is supposedly 80W max compared to the Q8200 at 95, so I'm a
bit surprised. They seem to both idle around 50C, compensating for the speedfan
errors on the E5472, with speedfan controlling the CPU fan speed according to
temp.

I thought these newer processors were suppost to slow down if they get too hot,
rather than just crashing. Could it be a memory error? The DDR2-800 memory
should be able to handle this speed, right? ASUS claims this board is good to
FSB 1600, which I understand matches the DDR2-800 memory

I've got the Q8200 back in now, as this is my HTPC machine, so I don't want it
crashing, but will do more playing with the E5472 when I have the opportunity.

I'd appreciate opinions and suggestions.

[Paul]

The processor should throttle if it gets too hot. And if it gets
20C above the throttle temp, the whole computer shuts off (known
as THERMTRIP).

*******

So, we need an excuse for why it would get hot...

1) Heatsink isn't sitting flat on the CPU.

Or the TIM underneath the lid is defective - highly unlikely on
the LGA775 ones, as they used low temperature solder and the lid
s soldered to the silicon die. It's one of the best TIMs there
is (in terms of not being defective). Modern processors, like the
very latest Haswell, have switched back to "cookie dough" style
internal thermal interface material. Some flavors of cookie dough,
are not uniform from one section to another. Or even have voids in
them.

Intel switched from the low temperature solder (so they claim),
because the low temperature solder is a "conflict mineral".
I think they stopped using it, to boost the profit margin :-)
Solder is more expensive than the cookie dough they use.

2) Not enough thermal paste or too much thermal paste between CPU and HSF.

3) VCore higher than intended (shouldn't happen on modern CPUs).

My LGA775 processor, I think there is a register inside the
CPU which is "range checked". The register is loaded with a
number, that drives the VID pins. The only way to overvolt, is by
using the offset pin on the VCore switching regulator. On my
Asrock board, that's the pin I had to do a mod on, to get some
VCore boost for overclocking. The LGA775 I'm typing this on, has
proper BIOS-inspired offset pin overvolting, if I wanted to overclock.
No mod is necessary on this motherboard.

There was a time, when the BIOS could mis-interpret the CPU type,
and by using VID override, pump the wrong voltage into it. Your
board is modern enough to not be doing that. Only if you entered
the BIOS and intentionally boosted above the range-checked value,
could you warm up that CPU. (Some BIOS, display the VCore value
field in RED, if it's set really high.)

4) The CPU can be overclocked by increasing BCLK. You would use CPU-Z
or similar, to verify stuff like that. If Intel EIST (SpeedStep) is
disabled, the multiplier stays at the high value all the time, which
makes things a bit warmer.

There is certainly a history of this sort of funny business,
but it's the era of the hardware that suggests nothing
nefarious is going on. So about all you can do, is take a lap
through the BIOS settings, later, review with CPU-Z, to see
if anything is dialed too high.

On my new board, I got off to a bad start, when the
fan was spinning at the wrong speed. Turned out the
BIOS defaulted to "really quiet fan settings". I had to
disable fan control entirely, to get decent cooling.
I was shocked at the time, that I was getting "low fan speed"
warnings in the BIOS. When I thought they'd solved those
problems years ago. I used to have older systems here,
that would start whining (and stop booting), fi the RPMs
of the CPU fan were below 1800 RPM. My new board might
have been running the fan at 1200 RPM and I'm getting
a warning. I guess I'm happy I got the warning, because
it did get me to look at the settings. But I'n not happy
with the default behavior of the fan control. "Aggressively slow."

Now, my CPU runs cool as can be, even when (measured value)
it is burning 156 watts. The worrying part, is the VCore
regulator is too hot to touch. I had to fit an extra fan
next to Vcore to bring it into range. VCore will still be
hot, right at each MOSFET, but the puny fins on the Vcore heatsink
are no longer scalding hot. If MOSFETs get too hot, the
channel resistance goes up (potential for thermal runaway).

Paul

[Bob F]

I just re-installed the E5472, and modified Speedfan to compensate for the 15C
temp offset for reading the E5472. With the compensation, SpeedFan reads the
same as CoreTemp.

I ran MemTest86+ with no errors, with my ram at both 6-6-6-18 and then 5-5-5-15.
Funny thing, memtest86+ on the Q8200 showed the RAM speed as 4394 MB/s at
6-6-6-18 setting. The E5472 shows 3969 MB/s at 6-6-6-18 and 4197 at 5-5-5-15. So
the E5472 is displayed as slower on Memtest86+. The time for a whole pass
testing the memory was faster with the E5472 however. It took 33:42 on the
Q8200, and 30:32 with the E5472, both at 6-6-6-18. At 5-5-5-15, that was 29:33
on the E5472. This suggests something funny about the MemTest86+ speed reading.
Just looked, MEmTest86+ has a new version. I'm at 4.1, so I need to get 5.1 and
try that.

I ran the Prime95 torture test for 35 minutes without a problem (at 5-5-5-15).
Core temps maxed at 67C. Interestingly, coretemp shows Tjmax as 100C, although
I've found numbers from 71 to 85 online. Intel lists case temp max of 67C, which
I'm about 10C under.

It looks like this E5472 on my P5K Premium is a GO! I guess it's time to try
overclocking it a bit.

[Bob F]

I am now running at 3.3 GHz (FSB 1761 - DDR2-880)) without problem. At first
when I got to 3.3, the temp under Prime95 was pushing the limits. The default
CPU voltage bounced around 1.25V, and since the spec is .85-1.35, I tried
reducing that voltage, and finally settled at 1.18V setting, which displays on
Speedfan as 1.16V. Running Prime95 at that voltage indicated no problems, and
the core temps now stayed below 70C. CPU case temp got up to about 62C. RAM
voltage remains at the default 1.8V. I'll keep my eyes open for a better
heatsink than the standard Intel assembly, but I'm quite happy with these
results. The PC definately is faster.

[Bob F]

I did more research about the Tjmax value for the E5472, and it seems that 85C
is the consensis. RealTemp uses that value, and CoreTemp uses 100, which I can
to figure out how to change. So, Speedfan was initially displaying the correct
core temps, and my temps were OK (on the second test described in another post.
My idle temp currently is around 32C, and my temps in the hot Prime95 torture
test are in the low 50's, at 3.3GHz overclock. This is a nice processor if you
have a motherboard that will handle 1600 FSB.