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Intel Core i7 and Hyperthreading

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December 10, 2008 3:56:27 PM

Hello everyone.

Remember how hyperthreading would cause a performance hit in several applications, and would benefit only those that were optimized for it? I don’t remember if I saw these particular results recently, but why not try turning it off in the BIOS with the new processors. Let’s see what results we get. I don't have this processor so I can't run the test myself. But I would like to see some results from it. Take care.
December 10, 2008 4:30:59 PM

I think some of the benchmarks I've seen suggest that HT brings performance up about 6% or more overall. Not sure what applications take a hit, but it seems like it's beneficial to keep it on.
December 10, 2008 6:42:33 PM

I should have been more specific in my post. Sorry about that. I meant hyperthreading on the Pentium 4's. I remember seeing benchmarks where there would be between a 5% and 15% performance increase when hyperthreading was turned off in BIOS - just wanted to see if that was the same in this situation.
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December 10, 2008 7:06:57 PM

Then why did you say Core i7 in the subject line?
December 10, 2008 7:24:09 PM

I understand where you're coming from, but there was a major revision on how they did HT in Core i7 compared to how it was done on the Pentium 4's. They changed which kinds of threads were "combined" to run on a single core. The old HT would combine any two threads, whereas the new version will only combine threads that use different parts of the processor core. Also, because multi-threading is much more common now, more applications will see a benefit from it.
December 10, 2008 7:31:29 PM

sounds efficient, too bad amd cant learn hyperthreding
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December 10, 2008 7:48:45 PM

^ Hyperthreading was originally used because the P4s were not too efficient. It allowed the CPU to do two different things at the same time, well assuming that the threads used different parts of the CPU anyway. If one thread was loading or storing values while another was doing a floating point calculation then it worked out. If both were trying to use the same resources though one thread would have to be paused till the other one completed it's operation. Because of the long pipeline it made sense on those CPUs, but it would have to be implemented differently on AMD CPUs. Due to AMD and Intel's cross licensing I don't think it would be a legal problem for AMD to use something like Hyper Threading and call it something else.
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December 10, 2008 9:17:15 PM

i hear good and bad things about HT. i doubt it will make an impact anytime soon.
December 10, 2008 9:50:47 PM

8 threads are getting a bit rediculous for the avg consumer. then they want to bring out an 8 core too?
December 10, 2008 10:25:40 PM

and thats y the "average consumer" has problems with vista and programs like it. if it were up to them, we'd still be running single core programs with 8-bit graphics. yet i dont hear them complaining when the latest Iron Man movie has awesome special effects.

if high-definition, hardcore gaming, heavy-duty editing (video and sound), and kickass OS's are going to advance, we need the 8+ cores. innovation ftw!
December 10, 2008 10:43:15 PM

I believe the main bottleneck here is the coding and programming the in the applications themselves. Until someone comes up with some good multi-core code its going to be hard to see the benefit.

In benchmarks i've seen for the i7 some have given HT on / off in the results, the majority of the time there was improvement with HT on but very little.
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December 10, 2008 11:26:04 PM

It is also worth mentioning that back when the P4's HT was introduced, there were no multi-core CPUs, softwares were mostly single-threaded. Since then, we had dual and quad cores coming out so developers started multi-threading their applications much-more. There HT might be of much better benefits, not to mention, as others already suggested, that the i7 architecture is way better than the old P4.
January 19, 2009 11:44:23 PM

Re comment: "8 threads are getting a bit rediculous for the avg consumer. then they want to bring out an 8 core too?"

All depends on the "average consumer" just five years out. Yeah, 8 lines in seems excessive, but realize that the PS3 has
JUST that already (IBM cell sdk)!!!
Yes, average word processing etc. could NEVER have need for that much speed. The SW has to be completely different to support it; current C+ presents stuff as a pile of info infront of the CPU; 8 SPU's (in the Cell) prefer 8 piles of stuff infront of it, and not necessarily huge piles at that. Hence, video and audio feeds, vetices, shader info. well, it goes on... but it's all for 3-d intesive realtime rendering.
February 17, 2009 11:35:31 AM

The move to multithreaded is not new to "average consumers". The number of dual core and multicore systems, especially notebooks is inevitably increasing.

The improved implementation of Hyper Threading is a logical and I believe a good choice when you consider the financial drive for intel to improve upon the existing quad core technology. Virtual cores being cheaper than real cores... :D 

The "enthusiast" can enjoy the benefits of increased cores availible due to Hyper Threading whilst the so called "average consumer'' can enjoy the reduced cost of existing quad core technology if such a thing as "average" can be defined these days. :heink: 
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February 17, 2009 11:41:53 AM

afloatingfish said:
Re comment: "8 threads are getting a bit rediculous for the avg consumer. then they want to bring out an 8 core too?"

All depends on the "average consumer" just five years out. Yeah, 8 lines in seems excessive, but realize that the PS3 has
JUST that already (IBM cell sdk)!!!
Yes, average word processing etc. could NEVER have need for that much speed. The SW has to be completely different to support it; current C+ presents stuff as a pile of info infront of the CPU; 8 SPU's (in the Cell) prefer 8 piles of stuff infront of it, and not necessarily huge piles at that. Hence, video and audio feeds, vetices, shader info. well, it goes on... but it's all for 3-d intesive realtime rendering.


And yet the Cell is completely useless on the desktop market. Mainly because its not optimized for x86 code and is much more difficult to code for, hence why the PS3 games take longer to make and not as many exclusives exist anymore or game companies like VALVe decide not to release their games on due to this. Well some get there but only because EA buys the rights to port it.

But hell lets look at it this way. Next step from Intel is Westmere. They say it may have 6 cores. But then again they already have a 80 core CPU. No need for that power except in servers.
February 17, 2009 12:04:39 PM

But hell lets look at it this way. Next step from Intel is Westmere. They say it may have 6 cores. But then again they already have a 80 core CPU. No need for that power except in servers. said:
But hell lets look at it this way. Next step from Intel is Westmere. They say it may have 6 cores. But then again they already have a 80 core CPU. No need for that power except in servers.


I agree with your point... How many people really "need" even a dual core system to do most of the things they do on a computer.


However I remember some words of wisdom... "Build it and they will come".

I believe having 6 or more cores will become the required norm in the future. The computer industry is driven to build the next best thing in order to survive regardless of weather it is needed or not.
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February 17, 2009 12:16:25 PM

BrendanS said:
I agree with your point... How many people really "need" even a dual core system to do most of the things they do on a computer.
I believe the 2nd core is really useful to most people, even if just to offload all the OS processes so their application can have a "full core" to itself (I know it's not that simple, I just don't want to make things complicated), it makes a much smoother experience overall.
February 17, 2009 10:52:11 PM

Zenthar said:
I believe the 2nd core is really useful to most people, even if just to offload all the OS processes so their application can have a "full core" to itself (I know it's not that simple, I just don't want to make things complicated), it makes a much smoother experience overall.


I couldn't agree more having multiple cores is useful for multitasking , reducing the impact of those hanging application problems (which i used to remember getting all the time :o  ) and giving better responsivness overall. :) 

Just remembering back to those good old days when my PIII 733 was seemingly lightning fast. And how quickly I just got used to having a sense of speed and power and finding I was wanting the next best thing. Despite the glacial "slowness" of it now at the time I can remember thinking why would I "need" anything faster than my humble PIII. Even now it will still run the applications (such as word and firefox) I "need".

But then again I think I'm getting way to philosophical about the whole thing lol.
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February 18, 2009 12:25:48 AM

I think "multitasking" is way overused as a concept. Many people now seem to think they need a quad core simply because they use WMP, Word, Excel, IE and other apps like that. Most applications use no CPU when not used, they only eat RAM. IMO, the only "real" multitasking is "heavy tasks" like encoding MP4 file while recompiling my Linux kernel and watching a video in full 1080p resolution with surround sound... THAT is multitasking...
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