Asus P5G41T-M LX throttling CPU, but CPU not overheating!

[Assimilator1]

Whilst running OCCT CPU test (not linpack option) to test stability I noticed that the CPU was being throttled, multiplier drops to x6, & vcore drops too, FSB doesn't change, it starts after less than a minute & then goes up & down in fairly regular intervals (throttling last about 30s, full speed mostly lasts 30s, but sometimes a bit longer).

In the bios I have disabled C1E & EIST so their should be no CPU speed drop from those, aside from which OCCT runs the CPU at 100% load.
Peak CPU temperature on the hottest core is 56C (checked with speedfan & realtemp) when running OCCT upto the point the CPU is throttled, then it drops of course. This naturally is a long way from the temperature throttle point (realtemp says '44' away) employed by Intel in their Thermal Monitoring protection. Yet if I disable that option in the bios, throttling doesn't happen!

Why is it throttling when the CPU is not getting too hot?
AFAIK Intel's specs for TM only monitor CPU temps, does Asus add monitoring of other chips? VRMs???

Btw all voltages are at default (auto) bar vRAM at 1.5v. FSB 365 MHz, PCIE 106 MHz (had to increase that to get FSB over 343 MHz!). OCCT loaded vcore is 1.144-1.152v (via CPU-Z).
I have used my IR thermometer on the NB heatsink & it showed a temp of ~60C at the hottest point when running OCCT (& when not throttled). It's rather hot but didn't seem to bad to me, besides which, AFAIK TM doesn't monitor that, right?

Does not throttle running SETI, even when Milkyway@home is running on the GPU too.

Any idea what's going on? (oh & yea I know this mbrd is a POS, stuck with it ).

Googling didn't turn up much, though 1 guy had the same problem with Prime95 - http://www.tomshardware.co.uk/forum/278526-29-thermal-monitoring - he never got a proper answer.

The rigs specs.
Q9550 @3.1 GHz, 365 MHz FSB, all voltages are on auto which are the default setting (have confirmed by measuring power draw from wall), bar vRAM 1.5v. 8 GB DDR3 1333 RAM is underclocked @1168 MHz, HD 4830, 1TB HDD, Win 7 Ult 64bit

Any ideas?

Btw have I chosen the right forum section?

 

[coffeejunkee]

Pretty sure some kind of vrm throttling is going on, or some form of overcurrent protection. 3 phase, no heatsink: bad overclock board.

 

[Assimilator1]

I believe the mbrd is 4 phase (can't remember where I read that now) & it does have a HS on the NB, or did you mean for the VRMs?

I think I could recognise them if I saw them, what sort of temps should VRMs stay below?
Anyway to know when the VRMs are undergoing overcurrent protection?

Btw this mbrd supports upto the Q9650, 3GHz, do you think just that extra 100MHz & 32MHz FSB would be enough to trigger overcurrent or heat protection?

 

[Assimilator1]

Since found it does throttle running Asteroids@Home (at 3.1 GHz anyway), that project is better optimised & the rig draws more power & the CPU runs 3-4C hotter than Folding@H or SETI.

I've since down clocked it to 2994 MHz & I still get throttling with OCCT! Though it's not as often (I can post a graph if anyone really wants it).
I've also pointed my IR thermometer on the 2 visible VRMs* (3.1 GHz, running Asteroids@home), one's on ~51C the other 48C. This seems to be roughly bourn out by touching it , it's hot to touch but I can keep my finger on them for a few seconds. So not terribly hot, those are ok temps aren't they?

*I believe they're the VRMs anyway, black little boxes about 1cm across, under the HSF retention bracket.

 

[coffeejunkee]

Like they say, haste makes waste. I put too much trust in Google and looked at the wrong motherboard and I also though you were talking about 3.6GHz like your sig says. Furthermore, I skipped the part of your post about Thermal Monitoring.

Anyway, board has 4 phases but still no heatsink on vrm's (those little black thingies next to the phases). I can't really explain why it doesn't throttle with TM disabled, you're well under 100c Tjunction throttle point so it shouldn't throttle either way.

I'd first try running stock, see if any throttling appears in that case.

 

[Assimilator1]

Yea it does help to read the posts thoroughly , too much coffee? lol.

And I don't get why it's throttling either, I can only guess Asus includes VRM monitoring with CPU too? But that still doesn't make sense as the 6 (8?) VRMs are only at 50-60C & just fairly hot to touch (have to withdraw finger after a few seconds).
Not to mention at 3.1 GHz I'm only 3.3% over it's maxed officially supported CPU speed, so you'd think with that modest cpu o/c & stock vcore it'd be ok?? *shrug*

And although I haven't run stock FSB yet I have run what would be stock MHz for a Q9650, which is supported by this mbrd, allegedly!

I'll try totally stock now.
Incidentally power draw from the wall @ stock is down only 6-7w vs 3.1 GHz, @160-162w running OCCT CPU. So a very small difference in power usage.

 

[Assimilator1]

I've just seen it throttle at stock speed (well 334 MHz FSB, Asus like to bump up their stock FSB). So even at 2.84 GHz it's throttling it to 2 GHz (x6 multi).

Stupid mbrd , oh btw I've also emailed Asus tech support, see if they come back with anything useful in the next few days.......

 

[Assimilator1]

Sort of update here http://forums.anandtech.com/showthread.php?t=2365911

And any further updates will be in that thread too.

 

[bailw]

Check your CPU features and turn off "CPU TM function"

 

[Assimilator1]

As I mentioned in my 1st post I've already done that , however I'm not happy really running it without this safety feature.