Running down my cache to install latest optis and noticed something I didn't expect - I thought that the i7's were smart enough to use a full core for single threaded tasks if not all of them were being used.

Ex. Windows shows 8 cores in task manager. I am running 3 MB tasks. It uses 3 hyperthreaded cores (38% CPU) instead of 3 full cores (75%)

I am guessing my understanding is incorrect - and they haven't gotten to a point where it can dynamically switch between HT and NON yet. Yes?

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No it hasn't. That's why to use or not use HT has to be changed in the BIOS.

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I believe the cores are grouped in twos--i.e. core 0 and core 1 correspond to one physical core, core 2 and core 3 are another, etc. It really doesn't matter if a process runs on core 0 or core 1--it's the same physical core.

Windows will normally spread tasks out among all 8 cores. If you set BOINC to run 50% of CPUs, then manually set affinity for those 4 running tasks such that they're running on cores 0,2,4 and 6, you'll see even core temps and load. Of course the load will only be 50% (according to Windows) since you're not using hyperthreading. But that scenario would be basically equivalent to running without hyperthreading at all.

There must be some advantage to running hyperthreading or there would be no point in offering it in the first place. One way to verify this that I've found is using y-cruncher (a multithreaded pi digit calculator)--benchmarks are significantly faster with HT on. I imagine you would get the same throughput improvement in SETI@Home although it's very difficult to verify.

You're correct in that hyperthreading can only be switched off or on in the BIOS.

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Thanks for clarifying my understanding guys. Preciate it.

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Running down my cache to install latest optis and noticed something I didn't expect - I thought that the i7's were smart enough to use a full core for single threaded tasks if not all of them were being used.

Ex. Windows shows 8 cores in task manager. I am running 3 MB tasks. It uses 3 hyperthreaded cores (38% CPU) instead of 3 full cores (75%)

I am guessing my understanding is incorrect - and they haven't gotten to a point where it can dynamically switch between HT and NON yet. Yes?

The OS kernel still treats a CPU thread/pipeline as a full CPU, so 3 tasks on a 8 thread system will always = 38%. Core i7 is 4 cores + 2 threads per core. What would be smart is loading up each core (of 4) with only 1 thread first, and if more than 4 tasks are running, only then fill up the rest of the threads. The linux kernel, BTW, is aware which threads belong to which core, and it will schedule threads on different cores before doubling-up. Not sure about Win 7 but definitely Vista & XP are NOT this smart.

Win 7 does same. Called "SMT Parking".

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This is off subject somewhat, but I'm wondering what sort of core temperatures you are getting when using the i7-930 with all 8 tasks running. I'm getting in the mid 70's and this seems high. Since I just got this board, I have nothing to compare it to, other than my old core 2 duo, which ran much cooler.
thanks

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Greetings Michael,

I just built an i7-860 rig and it is running in the low 60s (I'm assuming you mean Celsius). But, that is without BOINC running on it, yet. It is also running the stock fan which I may end up having to replace. I was going to do some googling to see if I could find a safe operating temperature range. I'm not sure how much different the 860 is from the 930, unless, as my memory seems to be telling me that the 930 is the new 6 core CPU. I could be wrong though. :)

Hope this gives you some basic help. :)

Keep on BOINCing...! :)

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CAPT Siran d'Vel'nahr - L L & P _\\//
Winders 11 OS? "What a piece of junk!" - L. Skywalker
"Logic is the cement of our civilization with which we ascend from chaos using reason as our guide." - T'Plana-hath

Greetings Michael,

I just built an i7-860 rig and it is running in the low 60s (I'm assuming you mean Celsius). But, that is without BOINC running on it, yet. It is also running the stock fan which I may end up having to replace. I was going to do some googling to see if I could find a safe operating temperature range. I'm not sure how much different the 860 is from the 930, unless, as my memory seems to be telling me that the 930 is the new 6 core CPU. I could be wrong though. :)

Hope this gives you some basic help. :)

Keep on BOINCing...! :)

The i7 CPU 980 is the 6 core. I just got one, and have it running at 58° C at 4.2 GHz. The spec is 67.1°C.

Steve

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Warning, addicted to SETI crunching!
Crunching as a member of GPU Users Group.
GPUUG Website

-[ snip ]-

The i7 CPU 980 is the 6 core. I just got one, and have it running at 58° C at 4.2 GHz. The spec is 67.1°C.

Steve

Hi Steve,

Thanks! I knew it was 9xx, just not sure of the xx. Still need to google... :)

Keep on BOINCing...! :)


[edit]
I did some googling and checked my current temps and settings. I found specs that say 860 temp range is 5 - 72.7. Mine is currently at 52 (without BOINC yet). I would guess that mine is within established parameters. :)
[/edit]

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CAPT Siran d'Vel'nahr - L L & P _\\//
Winders 11 OS? "What a piece of junk!" - L. Skywalker
"Logic is the cement of our civilization with which we ascend from chaos using reason as our guide." - T'Plana-hath

Before:
4033 MHz, 1.28 V VCore(which is +0.1 V over default), 1,24 VTT(+0,14). Megahalems cooler, NB XLP 2 @1600 rmp push, and NB XL1 @1200 pull - 75-80 load with SETI + 275 GPU in case. Room temp 18-20 deg.

Now:
4110 MHz, 1,31 V VCore(which is +0,13 V over default), 1,28 VTT(+0,18), custom water cooling, not maxed out - 67-72, 70 average. Room temp 24+(26 today) degrees, its becoming hot in Bulgaria already. Idle is bellow 40, but these don't count, Intel says idle temperatures must not be counted as true values.

Using SSE4.1, instead of SSSE3 client, seems to me, gives +1 degree more.

i7-860 should run hotter and it does, ppl say, bcs of integrated PCIe controller

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I assume the spec is at 100 % load? Where did you find the spec, or another way, what is the spec for the 930?

thanks

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Yes, 100% load, after hour or so, to ensure that system has reached maximum warm up.

What specifications do you need about 930?

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My 930 under full load... well, it varies. 75c at the moment under full load. The weird story is programs i use to monitor cpu speed + my bmessage at post report that this baby sometimes runs with a multiplier of 22. That i don't understand. Current clock speed is 22 x 147. So, 3.234 ghz.
When i bought the MB it has a very outdated bios. No option to change multiplier up, just down. Upgraded the bios and magically the number 22 appeared as an option.
Not good with saving pics, so can someone explain how i take a picture of say CPUID, and post it here?

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My 930 under full load... well, it varies. 75c at the moment under full load. The weird story is programs i use to monitor cpu speed + my bmessage at post report that this baby sometimes runs with a multiplier of 22. That i don't understand. Current clock speed is 22 x 147. So, 3.234 ghz.
When i bought the MB it has a very outdated bios. No option to change multiplier up, just down. Upgraded the bios and magically the number 22 appeared as an option.
Not good with saving pics, so can someone explain how i take a picture of say CPUID, and post it here?

Use the 'Print Screen' button on your keyboard and paste and crop the image in your favorite image editor...

That clock speed is a bit low for a i7 930... any reason as to why it isn't running at 3.7GHz+?

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- Luke.

Yeah 1 good reason. Stock cooler. I don't run it over 80c.

Here's a link to the CPUID page that has my processor stats. Odd beast it is.

http://valid.canardpc.com/show_oc.php?id=1166533

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My question about the temperature began after I made the mistake of letting
the store install the heat sink on my new board/cpu. I was getting temps in the
80's C which I thought was extremely high. Gigabyte agreed, so I took it back and they reinstalled the heat sink. The temps went down into the 70's but Gigabyte still thought that was high. I ended up taking it apart and reinstalling myself ( as I should have to begin with). I discovered that the store had used something sharp to scrape off the old thermal compound and scratched the heat sink, but the killer was that one of the clip screws was stripped and wouldn't tighten down properly. Moral is, if you want something
done right, do it yourself. I am now using the Corsair H50 liquid cooler. Temps are in the high 50's at full load with 8 tasks running without
overclocking on the i7-930.

thanks for the info

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