Does an i7 with HyperThreading off symply become a i5 with more L3 cache ?

Velve_87

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Sep 22, 2012
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Hello,

I'm planning on buying a new desktop computer.
After doing my research I've fount that aside from HyperThreading, the only main difference between current generation i5 and i7 processors is that the latter have 8MB L3 cache while i5 processors have 6MB.
I'm really attached to having 8MB L3 rather than 6MB, while i won't be needing HT.
So my question is: For identical clock rates, will buying an i7 and turning HT off be the same as having a 8MB i5 ?

Thank you in advance for your answers
 

oxford373

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Jun 22, 2009
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both core i5 and core i7are quad cores but the difference between i7 and i5 is hyber threading which allow every one physical core to process tow threads
but almost all programs and all games don't support more than 4threads so core i5 and i7 have the same performance for most applications ,but if you want it for professional programs i7 definitely faster ,also the extra 2mb in core i7 make it 1-2% faster per hertz which i think dont deserve the extra money.
 

InvalidError

Titan
Moderator

For most intents and purposes, yes.

Unless you run benchmarks that are optimized for 8MB cache to give the i5 a much larger cache miss rate handicap, performance between i5 and i7 with HT off would be practically identical.
 

Luke Cool

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Nov 22, 2013
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The processor is made up of billions of transistors, these form gates counters, an execution engine, cache, and other parts. The architecture is the way these parts are configured to work with each other. The more expensive processors , like the I7, have a more highly refined architecture.

Is a more highly refined architecture.a really poor investment? Not for Me!! But, for some people, anything past a $400 WalMart computer is a poor investment. I, my self, am a power user, and I strive to minimize user limitations on my builds.

???? The performance between i5 and i7 with HT off would be practically identical.????
This statement is an over simplification. Most programs are simple and are only written to use one core. For these programs, the above statement is true. But some programs and games are very complex and demanding, and are written to fully utilize hyper-threading and/or any number of cores they have excess to. The degree of benefit you see in a hyper-threaded or multi core processor depends on how well your software and the operating system are written to efficiently manage that specific extra resource. Hyper-threading has been around longer, so there is more hyper-threading friendly software out there than multi core, but there is no substitute for an additional core.

***A hyper-threaded processor's cores each contain an execution engine that manages, and shares its resources between, two logical processors. On a hyper-threaded core, you have two thread paths through this core, each path is able to use only about half of the cores processing power. With hyper-threading inabled, a 30% performance improvement is possible, but more than 10% is likely.
***A regular processor's cores each contain an execution engine that manages a single physical processor. On a dual core processor, you have one thread path through each core, each path is able to use 100% of the cores processing power. With use of a second core, an 80% performance improvement is possible, but more than 40% is likely.

With a hyper-threaded multi core processor, you have the best of both worlds.
 

InvalidError

Titan
Moderator

That statement was the correct answer to the OP's question which was specifically about i7 with HT turned off.

BTW, welcome to the art of thread necromancy... the message you replied to was over a year old: September 2012.