# Enable HT vs disable HT ???



## jonathan1107 (May 14, 2011)

Hey guys, I'd like to know what are the pros and cons of enabling or disabling hyperthreading for my CPU.

Look @ my specs for more info about my CPU... Also I have another quesiton: 

Where can I get advanced computer lessons (I need to learn advanced overclocking) I'd like to learn more about Overclocking my system to it's best...


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## hat (May 14, 2011)

If you disable HT, generally you get less power consumption and less heat generated... and you may actually be able to get more performance out of your system by disabling HT, as long as you're using programs that use  <=4 threads. You should be able to overclock higher without HT as well.


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## micropage7 (May 14, 2011)

it based to your apps, ht would help if your apps just use 1 or 2 cores. but if your apps could max the whole cores you could off it
but for daily use better you turn it on


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## OneMoar (May 14, 2011)

micropage7 said:


> it based to your apps, ht would help if your apps just use 1 or 2 cores. but if your apps could max the whole cores you could off it
> but for daily use better you turn it on



uh bit backwards there
HT OFF for gaming and daily use. 
HT ON for video encoding /compression task/ folding/


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## streetfighter 2 (May 14, 2011)

jonathan1107 said:


> Hey guys, I'd like to know what are the pros and cons of enabling or disabling hyperthreading for my CPU.


Seriously, I have no idea why anyone would bother disabling HT.



jonathan1107 said:


> Where can I get advanced computer lessons (I need to learn advanced overclocking) I'd like to learn more about Overclocking my system to it's best...


Everything you need to know about overclocking Intel i3, i5, i7 series:
http://www.overclockers.com/3-step-guide-overclock-core-i3-i5-i7/

Here would be a good place to get help with problems specific to your mobo:
http://www.overclock.net/intel-moth...al-asus-sabertooth-motherboards-club-tuf.html

For everything else there's visa-- I mean google.


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## jonathan1107 (May 14, 2011)

My daily usage of my computer is "moving files around" "editing and printing documents" "Surfing the Web" "A good number of hours of gaming a week" and "downloading"...

What would you recommend... I don't really convert files that much. I heard HT helps with multi-tasking... For example, I hear with HT transitions between an opened game and the desktop opened programs are more fluid... this true?


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## lilhasselhoffer (May 14, 2011)

Ok, here's the idiot's guide to HT (glossing over specifics).

Hyper threading takes a physical core, and allows you to have two logical cores.  Intel does this so that a chip can effectively double its logical cores.  This process does not actually double your speed in highly threaded applications.  It will increase performance in highly threaded application, but significantly less than adding physical cores will.

The HT process does generate extra heat.  Physical cores are forced to perform more calculations per cycle, and thus have more leakage.  More leakage means more heat.  This negatively impacts overclocking, but given memory bottlenecks may actually provide much more processing power in highly threaded applications.

Here's a rundown, from most to least, of stuff that benefits from threading:
Encoding
Encryption/Decryption
Multiple application
Native Multi-core games ---At this point the value of more logic cores starts to be questionable
Standard internet browsing
Older games
Office Programs

If you hover in the low end of the previous list then disable HT and get a slightly higher overclock.  If you are in the higher end then keep HT.  If you have a Gigabyte board then use the dual BIOS features.  We don't have a magic bullet for you; you need to decide what performance, and what compromises, you are willing to make.

As there is no official school for computing enthusiasts, google is your friend.  An introduction to overclocking, as well as specific information, is a search away.  I would recommend you follow what my peers have already said, and check through this forum.  Best of luck with your overclock.


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## niko084 (May 14, 2011)

HT is well known to cause FPS drops in games, so it is generally recommend to DISABLE HT for daily use and gaming. This was common knowledge for P4's with HT as well, this hasn't changed.

The ONLY time HT comes in handy is when you are running things as stated, stuff like WCG, F@H, video encoding, some editing software, anything that is extremely hard on the cpu for extended periods of time that will utilize the extra threads.

Saying you have an i7 in the gaming world since Sandybridge is just e-peen.


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## sy5tem (May 14, 2011)

i don't understand why you would need to disable HT. its like this , sometime its good and sometimes its not that good! .. will you reboot every time to enable/disable HT ? i think not, leave it on it doesn't hurt! its what i think. anyway you paid for it.


As for course in "overclocking" that doesn't exist because its something that you can learn for free easily trough reading and googling . 

just type overclocking "motherboard name" and read , then type overclocking "CPU model
" and read and after that you will get pretty much everything you need, just remember to watch you idle/load temperature with a software like coretemp or the like.


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## Neuromancer (May 14, 2011)

niko084 said:


> HT is well known to cause FPS drops in games, so it is generally recommend to DISABLE HT for daily use and gaming. This was common knowledge for P4's with HT as well, this hasn't changed.



Last testing I saw it goes either way, +/-3% except for some older game that did not work at all with HTT enabled. I recommend disabling it unless you fold/video encode


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## niko084 (May 14, 2011)

sy5tem said:


> i don't understand why you would need to disable HT. its like this , sometime its good and sometimes its not that good! .. will you reboot every time to enable/disable HT ? i think not, leave it on it doesn't hurt! its what i think. anyway you paid for it.
> 
> 
> As for course in "overclocking" that doesn't exist because its something that you can learn for free easily trough reading and googling .
> ...



How often does someone use their computer normally for browsing the internet and playing games compared to doing intensive operations that HT benefits....

Weigh your usage, less power, less heat, sometimes more clock speed, and an increase in performance when gaming it's very noticeable.

So to most, disabling it normally and just enabling it on the rare occasion you need it is the best option logically. Heck sometimes I don't bother restarting to enable it for most of the stuff I do, the time required to restart doesn't make up for the time I would have saved by having it on.

Unless you are folding or running some engineering software or running a server it's really not worth having generally, most video software that is used commonly will even use it.


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## niko084 (May 14, 2011)

Neuromancer said:


> Last testing I saw it goes either way, +/-3% except for some older game that did not work at all with HTT enabled. I recommend disabling it unless you fold/video encode



You can get a 3% bonus sure, then things switch cores and you get a serious stutter and a severe drop in FPS for an instant. Have that happen to you the wrong time especially playing an FPS game, doesn't take much to see the problem.

May as well just overclock your video card till you get display corruption and call it 3% faster.


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## HalfAHertz (May 14, 2011)

niko084 said:


> You can get a 3% bonus sure, then things switch cores and you get a serious stutter and a severe drop in FPS for an instant. Have that happen to you the wrong time especially playing an FPS game, doesn't take much to see the problem.
> 
> May as well just overclock your video card till you get display corruption and call it 3% faster.



That was only true with pentium 4 >.< I haven't experienced it with any of the i core processors with HT. But even with the P4s I still kept it on because it was really helpful and you could feel the difference in day-to-day use.


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## niko084 (May 14, 2011)

No it wasn't only with the Pentium 4, take a look around.

http://www.xbitlabs.com/articles/cpu/display/core-i7-975-950_7.html#sect0
As I said... This is common knowledge.

Record your frame rates with HT on in a game like Bad Company 2 *4 core capable* for awhile, then do it again with HT off, you will see the performance drops I speak of easily. Same goes for Supreme Commander which supports 8 threads.


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## RejZoR (May 14, 2011)

Why would you want to disable HT on modern Intel Core i3/5/7 processors? It's like buying a Mercedes SL65 AMG and then disabling its twin turbochargers. Disabling HT is only feasible if you know that you will be able to overclock that very same CPU higher because of it and gain more performance with higher frequency than simply doing more work per clock with HT.
I have it enabled on my Core i7 920 ever since and i haven't had a single problem because of it.

Some dude made a small test with and without HT:
http://www.overclock.net/intel-general/671977-hyperthreading-games.html

In all the cases it's either ~3 fps up or down (pretty much error margin) for each except in the TES Oblivion case, where he actually got benefit from HT with gain of whooping 28 fps just because of HT. Not that bad eh?


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## the54thvoid (May 14, 2011)

I have my i7 920 at 3.6 GHz and with HT off my temps are a good 10 degrees cooler.

The only logical way to assess the impact is to run a test with HT off at the highest clocks that are stable and then do it again with the same cooling with HT on to see which performs better.

You'll get a faster speed on the HT off scenario but the question is does that extra speed offset the 8 threads?  I'd say yes in most daily cases.  Most apps and games are still not coded for so many threads/cores.  Maybe in a years time or so, it'll be different.

But in a years time or so we'll be getting eight physical cores anyway (we already have 6 readily available).


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## jonathan1107 (May 15, 2011)

No worries, I've done my research and all in all, HT is worth it left enabled ;O) It does increase performance, reduce heat and power consumption to turn it off... But HT really boosts the performance of many tasks like "multi-tasking"... I often alt tab out of games to run multiple internet pages and I open loads of other programs too because I am overclocking and benchmarking...

About Overclocking lessons... I'm asking this because I have a new antec tpq 1200w PSU, and I am looking to learn how to use the 12v control knob that's behind the PSU...

I've heard stuff about it but no concrete info...


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