i7 thermal throttling?

[Aapje]

Originally Posted by alpertron

A cheap approach is (if you have no kids at home) to leave the left side of the case open. I was able to reduce from 79 Celsius degrees to 68 Celsius degrees the temperature of my old Duron 1300 MHz in this way on a very hot summer (up to 35 Celsius degrees in the room). Now I have a Core 2 Quad that runs a lot cooler.

Some cases cool better with the case closed than with the case opened. If you have a big fan in the back it may stop pulling air from the front (moving past the CPU) and that would be bad.

[alpertron]

That's why you need to monitor the CPU temperature as I did in my old PC.

[VJS]

Originally Posted by cheesehead

Some folks are better at playing with fire, or sword swallowing, than others.

Yeah and Ironbits could poop them out the other end with no harm, so the tape comment was uncalled for.

Thermal throttling with the i7 seems to come up more than it should. If your throttling with a stock HS in a standard case arrangement... IMHO this is an intel design flaw. (clock it back or provide a better heatsink from the factory)

[IronBits]

If you are running Linux, and you have not disabled anything in the bios, the OS will try to save you money by cpu throttling.
Windows XP/Vista will do the same thing.
YOU have to decide if it's thermal throttling by monitoring the CPU temps. - if it is, get a better HSF and monitor temps until you are satisfied.
My I7-920s run at 3.5GHz without hitting the thermal limits.
I NEVER use stock HSFs
I always turn off any feature in the BIOS that the OS can manipulate to the extent possible

If the OS is throttling the cpus, then disable that function in the BIOS so you get performance, not cost savings, if that's what you want.

I would not recommend doing any tweaking with the stock HSF.
They are only good for ugly paper weights, if that, and barely adequate.

I put black electrical tape over my HD DVD player neon blue light so it's doesn't distract me... does that count?

[IronBits]

Sometimes I can be such a DOLT.
Something was bothering me about this whole conversation, and I got distracted, I apologize.

To get maximum performance out of your I7 and prevent OS control over your CPU.
Disable
Intel SpeedStep Tech
C1E Support
Intel Virtualization Tech
Intel C-STATE Tech

If you have a quality 3rd party HSF and have good case ventilation, and you have monitored your temperatures and are satisfied, you can also tweak it to go faster.
Disable
Turbo Mode
set BCLK to 174
save settings, reboot, monitor temperatures...
IF everything looks good, start a client on all 8 processors and monitor temperatures closely for a couple hours, then check it every so often, then several times a day, then at least once or twice per day.

Never disable Thermal management, I never disable thermal management if the cpu and BIOS support it.
If for some reason something happens to the CPU fan and the CPU starts getting hot, it can shut itself down.

I hope I didn't confuse anyone and if so, I hope the above clears up all the issues and mis-understandings.

[xorbe]

Originally Posted by IronBits

To get maximum performance out of your I7 and prevent OS control over your CPU.
Disable
Intel SpeedStep Tech
C1E Support
Intel Virtualization Tech
Intel C-STATE Tech

I believe all four of these items are under the CPU's control for i7. Disabling VT is silly. I think C-STATE and C1E allow power savings in HLT mode. I believe I tried with and without #1/#3/#4, and it made no difference for performance. When the CPU is busy, none of them are active.

You are unlikely to fry the CPU unless you over-voltage too much, or the HSF falls off. It will lock up first.

Originally Posted by IronBits

set BCLK to 174

You can't hand out generic over-clocking advice like that. It's much more complicated and difficult to prove stable for i7.

[IronBits]

I disabled VT because I don't ever plan to do VM.
I'm not talking about power savings, I'm only talking about getting performance for 24/7 dedicated crunching computers. As you say, it may not make any difference in performance, so could probably be ignored.
You can not tweak for performance with a stock HSF without taking a chance on cooking the CPU, as they run HOT with stock cooling as it is.

Those are all the things I did to mine to achieve stable and reliable overclocks to 3.5GHz from an I7-920 using an Asus P6T Deluxe and MSI X58 Platinum motherboards, with HT enabled.
Using quality HSF that I purchased separately to provide maximum cooling.

I did this at the 1st of the year, and they are still running nicely. I did lose one MSI motherboard because of a bad 4-wire 12v connector that went bad, which is in RMA status. I replaced it with an open box Asus P6T Deluxe from NewEgg.

If you don't disable SpeedStep, the OS will have the ability to throttle your CPU.

[IronBits]

Not sure why this forum doesn't do inline images, but here is a shot of my temps on a I7-920 at 30% Overclock, in a enclosed computer case with a GTX295 running GPU version of Folding@home and Boinc 6.4.5 on SuperLink and Poem@home at the same time.

Everest Ultimate Edition 5+
http://www.ironbits.net/images/i7temps.jpg

[joblack]

Originally Posted by IronBits

I always disable thermal management in the BIOS before installing any OS for a 24/7 cruncher to prevent throttling.

Thermal Throttling and all the other Power Saving Methods have to be disabled. With Prime95 running they aren't necessary anyway and if you overclock they pull down the cpu clock rate.

[IronBits]

Originally Posted by IronBits
I always disable thermal management in the BIOS before installing any OS for a 24/7 cruncher to prevent throttling.

Originally Posted by joblack

Thermal Throttling and all the other Power Saving Methods have to be disabled. With Prime95 running they aren't necessary anyway and if you overclock they pull down the cpu clock rate.

To be absolutely clear, I DO NOT disable thermal management in any of my computers.
It is not necessary for a successful overclock and will cost you a CPU and possible fire if something were to happen to the HSF and you are not there watching it.

However, I do disable Intel SpeedStep Tech. to prevent the OS from messing with the speed of the CPU.
For instance, I have a Q6600 running as a Linux Server, and noticed it running at 1.6GHz instead of the normal 2.4GHz.

Looked into the BIOS and saw that I hadn't disabled speed step, so Linux was using that feature to save energy.
But not any more