What's the diff between HyperThreading and Dual Core procs?

[JimmyChunX]

Sorry if there's already a thread on this (I searched and didn't find), and I wasn't exactly sure which catagory to post it in(general, amd or intel), but I've been wandering this for a while.

What IS the difference between Hyper threading and Dual-Core Procs?

Besides what I've been able to deduce: that HT is purely logical and Dual-Core is more Hardware/physical (could be wrong)... what is the difference?... a little more detail would be appreciated... thanks...

 

[Dan_D]

Hyperthreading is a virtual processor using unused pipeline stages in the processors massive 20 or 31 stage pipeline to execute additional data. It first came about on the Pentium 4 Northwood Core "C" processors. The Prescott core "E" processors had the 31 stage pipeline which featured improved hyperthreading.

Basically it was Intel's way of picking up some performance out of their CPU's since most software didn't use all the stages in the processors pipeline to execute code. This allowed them to be more competetive with the Athlon XP series processors which could "get more done" in a given clock cycle.

Hyperthreading wasn't as good as traditional SMP systems, but offered great multi-tasking capabilities for the time. This also began forcing software companies to develope multi-threaded applications to take advantage of the technology. This helped pave the way for dual core processors of today. (Not enough paving was done in my opinion.)

Dual core CPU's have two processor cores in one physical package. The dual core CPU is very much like SMP systems, but it uses only one processor socket. This is faster than Hyperthreading, and accomplishes the same thing. More responsive computing and more processing power available to applications that are coded to take advantage of the technology.

 

[chrisf6969]

Hyperthreading is a virtual processor using unused pipeline stages in the processors massive 20 or 31 stage pipeline to execute additional data. It first came about on the Pentium 4 Northwood Core "C" processors. The Prescott core "E" processors had the 31 stage pipeline which featured improved hyperthreading.

Basically it was Intel's way of picking up some performance out of their CPU's since most software didn't use all the stages in the processors pipeline to execute code. This allowed them to be more competetive with the Athlon XP series processors which could "get more done" in a given clock cycle.

Hyperthreading wasn't as good as traditional SMP systems, but offered great multi-tasking capabilities for the time. This also began forcing software companies to develope multi-threaded applications to take advantage of the technology. This helped pave the way for dual core processors of today. (Not enough paving was done in my opinion.)

Dual core CPU's have two processor cores in one physical package. The dual core CPU is very much like SMP systems, but it uses only one processor socket. This is faster than Hyperthreading, and accomplishes the same thing. More responsive computing and more processing power available to applications that are coded to take advantage of the technology.

B+

Good information, I only subtracted a few points b/c you had one inaccurate statement. Hyperthreading was launched with the 3.06Ghz 533FSB "B" processor. At the time it was basically like the Extreme Edition offering an "extra" over the rest of the line. Then Hyperthread went mainstream with the "C" processors.

 

[PGHammer]

Hyperthreading is a virtual processor using unused pipeline stages in the processors massive 20 or 31 stage pipeline to execute additional data. It first came about on the Pentium 4 Northwood Core "C" processors. The Prescott core "E" processors had the 31 stage pipeline which featured improved hyperthreading.

Basically it was Intel's way of picking up some performance out of their CPU's since most software didn't use all the stages in the processors pipeline to execute code. This allowed them to be more competetive with the Athlon XP series processors which could "get more done" in a given clock cycle.

Hyperthreading wasn't as good as traditional SMP systems, but offered great multi-tasking capabilities for the time. This also began forcing software companies to develope multi-threaded applications to take advantage of the technology. This helped pave the way for dual core processors of today. (Not enough paving was done in my opinion.)

Dual core CPU's have two processor cores in one physical package. The dual core CPU is very much like SMP systems, but it uses only one processor socket. This is faster than Hyperthreading, and accomplishes the same thing. More responsive computing and more processing power available to applications that are coded to take advantage of the technology.

While HT was made popular with the Northwood-C series (all of which supported HyperThreading), it was launched with the 533 MHz (133 MHz quad-pumped) P4 3.06 GHz Northwood-B (this was, in fact, the only B to support HyperThreading). The C series was a heck of an alternative to both the Original Northwood (and to the Big Bad Bs) for reasons *other* than HyperThreading (mainly, the faster FSB and the lower prices compared to the Northwood-B).

The reason for the lack of paving in terms of multi-processing is largely because of the lack of a real *driving force* to upgrade hardware or software. While Windows XP has been SMP/multicore-aware from the beginning, there has been little drive to develop multiprocessing applications (even with HyperThreading on the shelf) because HT was only being used by Intel. AMD's decision to eschew HT in favor of multicore/multiprocessor architecture (and 64-bit processing), combined with their utter failure to get product out the door (except in their expensive-by-comparison Opteron and Athlon64 lines) left the software development community lacking a clear direction.

 

[w1retap]

In my computer engineering class the professor was discussing the difference between dual core and hyperthreading. To put it very simple..

hyperthreading - intel's single core processor technology switching between tasks really quick emulating a dual core processor. It will be slower than an actual dual core, and in some applications, it actually benchmarked lower than if you had hyperthreading disabled.

multi-core - a single processor with more than one core that is able to work on multiple processes at the same time.

 

[Flak Pyro]

B+

Good information, I only subtracted a few points b/c you had one inaccurate statement. Hyperthreading was launched with the 3.06Ghz 533FSB "B" processor. At the time it was basically like the Extreme Edition offering an "extra" over the rest of the line. Then Hyperthread went mainstream with the "C" processors.

I have one of these CPUs, they are rare i think, up till my E6700 it was my main cpu

 

[Parabellum]

HT is a dual core wannabe Really, I believe everything was well explained from the previous posters.

Para

 

[sabrewolf732]

Weren't alpha processors the first with HT?

 

[Dan_D]

B+

Good information, I only subtracted a few points b/c you had one inaccurate statement. Hyperthreading was launched with the 3.06Ghz 533FSB "B" processor. At the time it was basically like the Extreme Edition offering an "extra" over the rest of the line. Then Hyperthread went mainstream with the "C" processors.

I forgot about the 3.06GHz "B" processors.

 

[Dan_D]

Weren't alpha processors the first with HT?

I am not sure on that, I don't think so. I know the technology was originally referred to as "Jackson Technology" before Intel's marketting team turned it into "Hyperthreading". Additionally, the Xeon got the technology a little while before the Pentium 4 did.

 

[drizzt81]

I am not sure on that, I don't think so. I know the technology was originally referred to as "Jackson Technology" before Intel's marketting team turned it into "Hyperthreading". Additionally, the Xeon got the technology a little while before the Pentium 4 did.

http://www.theregister.co.uk/2002/06/18/what_the_hell_is_hyperthreading/

So how does it work? HT is Intel's implementation of a technique known as Simultaneous Multi-Threading (SMT), a technology originally mooted for the cancelled EV8 Alpha processor. It's also going to be implented in IBM's Power5 processor, due 2004.

If El Reg is correct, then the alpha was supposed to have it, but never got produced.