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i7's HyperThreading and heat...

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zizux

Member
Joined
Sep 21, 2001
Location
SLC, UT
I have come to notice something besides the obvious. Well maybe it is not so obvious so I'll inform those that don't know. With the i7's Hyperthreading = more heat. Some perhaps not so obvious things, other then benchmarking and seeing 8 cpu's in the task manager hyperthreading is virtualy useless for 98.89% of applications we all use on a day to day basis.

In games it slows down FPS typically, at least I have yet to find one that it increases it.

I wonder how exactly Intel implements it with the i7's, and if there have been changes? The cause for this wonder is that with my c0, I could run ~4ghz with it on or off, and with it on, in prime it was only ~5c hotter and also didn't require any more voltage then with it turned off.

Now onto the part that makes me wonder, my d0 which was packed in May of this year (c0 was March). My d0 goes from running 68 c max core temp to running 79 c and needing more voltage to remain stable in prime. Voltage without ht on - 1.325 in the bios, voltage with it on = 1.331 so there isn't a large increase. All the other voltages are the same.

Are these findings about average with what you all have seen?

On the quest to get over 30k in vantage with gtx 275's I got my cpu to run 4.4ghz, but it was nowhere near prime stable and required over 1.4v which for some might not be alot but to me that is a huge jump for not much return.

Anyway a few quick questions to sum it up;

Is something about the way HT is enabled been changed in the newer chips or is this just "normal"

Are there any programs that any of you have noticed a gain while using HT besides benchmarks but including games?
 

nascasho

New Member
Joined
Jun 14, 2009
Good question!

Personally though, I like the i7 HT on because of the task manager... it shows 8 threads... 8 freaking threads! Thats insane. And running that CPU monitor gadget for the Vista sidebar show 8 cores. I smile every time I see that.

Yes, i'm new to the whole i7 platform, lolz.

One place I see a benefit would definitely be Sony Vegas' video decoding/encoding or any video editing/creation software.

That thing will run your CPU use out the roof and I'm pretty sure it LOVES Hyperthreading.

Talk about 6min to 3min... whew!
 

Stilletto

Member
Joined
Jun 12, 2006
Location
Yulee, FL
Everything you say sounds pretty common to me, no worries.
One thing to remember though is that you may have lost a few fps, nothing that you will notice but when it comes to things that HT does well you most definitely WILL notice. When needed it is there and pays for itself. For everything else, it really doesn't hurt much. Think of it as a kind of reserve :)
 
OP
Z

zizux

Member
Joined
Sep 21, 2001
Location
SLC, UT
I have tried some video encoding but it was with some older software, and now that I can encode on my graphics cards I don't see a need to do it on the cpu.

I will test that tomorrow now that I have installed cs4 Master Collection.
 

Voidn

Member
Joined
Apr 24, 2009
Location
Crap Town USA
Lots of HT debates going on. If you have something that utilizes it, it helps. But not much utilizes 4 3ghz+ cores much less 8 threads. Like some i thought it was cool to have it. But now that I am seeing how much overhead it has I'm doing tests with it off. My temps dropped 4c in linx after turning it off. I'm doing benchmarks to make sure I'm getting extra FPS with it disabled. And when I have time I'm going to see if I can lower my vcore and thus my temps even more.

You might check out http://www.ocforums.com/showthread.php?t=609336

If I find something that actually benefits from it I will turn it back on.
 

deathman20

High Speed Premium Senior
Joined
Aug 5, 2002
Thanks Voidn. Was about post that link to the thread.

I know HT caused slow downs, but I always thought it was minor, at least thats what I remembered it to be. Such a small numbers 3% or less, that it wasn't worth turning it off to have it at my finger tips at a start of a program.

I know for a fact 1 program its powerful in 3D Studio max its very useful for having HT on. Pulling my old thread thought I had more facts in there but....
http://www.ocforums.com/showpost.php?p=6014017&postcount=82
HT added roughly 26-50% more power to the system rendering.

Heat from HT for me is high, adds roughly 7C to overall temp under LinX. As for turning it off, I can gain for sure ~100Mhz if not more. I know its less than 200Mhz from past tests. As said depends but from just a single game test, showing upwards of 29% hit in FPS... think thats pretty substatial.
http://www.ocforums.com/showpost.php?p=6130895&postcount=15

That thread thats ^ and this little mini link is a little something i was tossing togeather for a "Optimal" OC for i7 920. Where seems to be the sweet spot for gaming, without going over the top, yet still getting good performance. Course faster is always better ;), but for someone that wasn't a conservative clock, or reduce heat output, save some power, etc this is something that I and others can chime in on.

Currently im coming to a conclusion.. mind you im limited on time, and lack game benchmarks currently, but that from review sites and general talk from people that 3.6Ghz w/o HT seems to be "the spot" for clocks. I might just go for 3.66... just to have a 1Ghz OC :)
 

xtkxhom3r

Member
Joined
May 29, 2008
Location
San Antonio,TX
I have tried some video encoding but it was with some older software, and now that I can encode on my graphics cards I don't see a need to do it on the cpu.

I will test that tomorrow now that I have installed cs4 Master Collection.

what program do you use to encode with your video card? and what video card do you have?? i am VERY interested in this
 

deathman20

High Speed Premium Senior
Joined
Aug 5, 2002
what program do you use to encode with your video card? and what video card do you have?? i am VERY interested in this

Bet hes talking about the Badaboom.

Does it do WMV files? Trying to convert .avi/.mkv to .wmv files for X360 playback.
 

deathman20

High Speed Premium Senior
Joined
Aug 5, 2002
i guess you get what you pay for lol! ati does have something but i havnt had a lot of luck with it....

Sadly ATI has what I want which is WMV output and its quicker too boot, yet it does have some artifact issues.

Win some loose some. I know I might have to nab something because if I can find something that can encode WMV's much quicker than ~1min per min i'm good for that.
 

nzaneb

Senior Member
Joined
Nov 3, 2008
It's a monster if you're doing distributed computing. My 8 threads run 100% 24/7, unless I'm benching :beer:
 

Boulard83

Member
Joined
Jan 19, 2009
Its ALLLLLL depand on what you use your computer for. But for gaming ... it seems better to turn it off :(