What is difference between i3 i5 i7 ?

[c64]

It's not number of cores or cache. I can easily find same generation i7 and i3 with same cores and same cache. Frequencies as well.

So what is it? Instruction set? Some instructions run faster?

[LateLesley]

Au contraire, that is exactly the difference between i3,i5 and i7 cpu's. The i3's are usually lower end, a couple of cores, and smaller cache. i5 is your middle of the road, more cache, 4-6 cores, and sometimes faster clocks. i7 is your higher end, 6-8 cores, sometimes more, depends on the generation, but they are higher end parts.

Usually instruction sets only change between generations, but sometimes you get different models within a generation with an extra instruction set.

Another thing, is usually the higher end chips will work more efficiently, running higher frequencies at lower core voltages, whereas the i5s or i3s may not reach those speeds, or require more core voltage to reach them, making them more inefficient.

A site I like to use to tease out the differences between CPUs is CPU World. they are pretty good at listing the number of cores, frequencies, cache size, instruction sets, core voltage, and TDP. It's a very hand site for comparing CPUs.

https://www.cpu-world.com/CPUs/CPU.html

[oPossum]

Au contraire, that is exactly the difference between i3,i5 and i7 cpu's.

Not for 12th gen.

10 core i3  https://www.intel.com/content/www/us/en/products/sku/226257/intel-core-i31220p-processor-12m-cache-up-to-4-40-ghz/specifications.html
12 core i5  https://www.intel.com/content/www/us/en/products/sku/227850/intel-core-i51250pe-processor-12m-cache-up-to-4-40-ghz/specifications.html

[LateLesley]

Well 12th gen is muddying the waters a little, with its BIG/little set up (or Performance P cores and Efficient E cores)

You see both have 8 efficient cores, but the i3 has only 2 performance cores, and the i5 has 4 performance cores. so that is the differentiator.

There is also the hyperthreading of the P cores to consider, where they mention the "total threads". The E cores are only single thread, where the P cores can run two threads, which gives a bump in performance, usually around 1.5x what a single thread core will do. So the i3 in total can do 12 threads, whereas the i5 is 16 thread. (Which is similar to my Ryzen CPU 1800X - 8 cores, 16 threads. Though the i5 would trounce my 1800X due to newer architecture, and higher frequency.)

Another thing that muddies the water in Intel is the integrated graphics. You'll see in the specs, that the i3 runs the graphics engine at up to 1.1GHz, whereas the i5 can go up to 1.3GHz, so that's another area where there can be a gain in performance.

[c64]

Au contraire, that is exactly the difference between i3,i5 and i7 cpu's.

Example:
i5-9600 Processor 6 cores, 4.60 GHz, 9 MB Cache
i7-9850HL Processor 6 cores, 4.10 GHz, 9 MB Cache

Why they call first one i5 and second i7?

[LateLesley]

Well, first, you are not comparing like for like - the i5 is a desktop chip, and i7 is a mobile family chip. And the difference is the core efficiency and hyperthreading.

The i5 has hyperthreading disabled, so is only 6 thread, whereas the i7 mobile has hyperthreading enabled, giving it 12 threads.

But it won't be double the gain in performance, due to it's lower frequency and TDP - it's only 25W compared to the i5's 65W

https://www.cpu-world.com/Compare_CPUs/Intel_CL8068404165200,Intel_CM8068403358610/

I couldn't find a direct comparison of the two chips listed, but i got close with an i7-9850H, and you can see the 9600 can beat it, even though it has less threads.

https://cpu.userbenchmark.com/Compare/Intel-Core-i7-9850H-vs-Intel-Core-i5-9600/m826055vsm853186

[brucehoult]

It's not number of cores or cache. I can easily find same generation i7 and i3 with same cores and same cache. Frequencies as well.

So what is it? Instruction set? Some instructions run faster?

They are purely marketing terms with no technical meaning that might as well be sold as "Good", "Better", "Best".

The differences vary from generation to generation to generation, with the differences in any one generation generally coming down to one or more of:

- different number of cores

- Hyperthreading or not (looks like twice the number of cores, but typically gives maybe 1.2x performance boost)

- high frequency "turbo boost" modes on higher end chips, but less range on lower end, or maybe fixed frequency.

- more cache memory on higher end chips


Within the same generation, for tasks that fit in the number of cores and cache of the lower end chip, the performance at the same MHz should generally be near identical.

[Someone]

It's not number of cores or cache. I can easily find same generation i7 and i3 with same cores and same cache. Frequencies as well.

So what is it? Instruction set? Some instructions run faster?

They are purely marketing terms with no technical meaning that might as well be sold as "Good", "Better", "Best".

Pretty much thats all it is, marketing, like the numbers that follow, not always monotonic or comparable between each other.

Hyperthreading? i3-10100 or i3-10300, but then so did many of the historical i3's (to sell off smaller dies without disabled cores back then)
Cache is always lower on an i3 (L1 and L2 too, not just the headline L3) any where it wasn't?

[MazeFrame]

That i3-1220P is not a 10 core, it is a 2P+8E.
Same as that i5-1250PE, 4P+8E.
Intel Marketing is working better than their engineering.

For a mechanical-world example of what Intel did here:
Container ship: 4 Compressors, 5 Generators, 1 Main Engine = 10 Engines!

[SiliconWizard]

As Bruce said. While that depends on each generation, one common factor is usually that the i3 has less cache than the i5, and the i5 less than the i7.

Now if you can find a i3 with both the same number of cores as a i7 and the same amount of cache, I'll be all ears, maybe I missed it.

As to the instruction set, I think the more advanced extensions such as AVX512 were only available on the i7, but that may have changed.

[TechTaco]

For completeness, where each product sits in performance order:
Atom & Pentium & Celeron (Low Performance) -> i3 (Good) -> i5 (Better) -> i7 (Best) -> i9 (Beefy) -> Xeon (Server/Workstation Class)

Intel over the years has changed what distinguishes them so I recommend typing in to Google the type of chip followed by the dash and it's model number, and the word "ark" (which is the site Intel keeps their product specs) to get the datasheet to compare, i.e.:

Search the web for:  i5-6500 ark

Also, the first number of the model denotes the generation of the chip you're dealing with, for example:

i5-6500  = 6th Gen
i5-7500  = 7th Gen
i7-8700  = 8th Gen
i3-9100t = 9th Gen
i9-10850k = 10th Gen
i5-11400  = 11th Gen
i5-12600kf = 12th Gen

For many years (cough gens 3-7 cough) the generation number went up but not much changed.
This can be argued, but for the most part the product lineup saw significant jumps in the past decade with:

• 8th Gen upped the cores offered by default in all processors. (i5 now had 6 easily, something usually reserved for an i7, 2666MHz RAM support).
• 12th Gen introduced PCIe 4 support, the low power/performance cores, 3200MHz+ RAM, i5 now has Hyper Threading

These are all generalizations, but how I separate out the product lineup. For instance, if buying a used PC I'd definitely try to get an 8th gen over 7th because of the more cores, faster RAM they offered starting with those.

[Someone]

For completeness, where each product sits in performance order:
Atom & Pentium & Celeron (Low Performance) -> i3 (Good) -> i5 (Better) -> i7 (Best) -> i9 (Beefy) -> Xeon (Server/Workstation Class)
....
These are all generalizations, but how I separate out the product lineup. For instance, if buying a used PC I'd definitely try to get an 8th gen over 7th because of the more cores, faster RAM they offered starting with those.

Missing the sub categories like "X" series processors which are more significant than Pentium/Celeron or i3 vs i5 vs i7 designations.

Those generalizations make no sense, even within a single "generation" or Microarchitecture (they dont line up/match with each other, particularly if you span from Celeron/Pentium to Xeon). The ordering is not always fixed when i7's might come in 3 or more different "TDP" power ratings (at least 5 different power ranges in 11th series intel i7).

A colleague asked me why a real time application was running so slowly on their new "fast" laptop with newer/bigger/better specifications/generation processor than their existing computer. I explained out how they were only faster during peak boost, and slower for continuous processing. Its a real problem of the confusing marketing, and cannot be simplified away.

Rather than relying on guessing by the marketing, pick performance/value based on benchmarks. Last/older generation processors are often better value on performance per $.

[brucehoult]

A colleague asked me why a real time application was running so slowly on their new "fast" laptop with newer/bigger/better specifications/generation processor than their existing computer. I explained out how they were only faster during peak boost, and slower for continuous processing. Its a real problem of the confusing marketing, and cannot be simplified away.

Several years ago the company I was working for supplied employees with thin laptops (Lenovo X1 Carbon) with i7-8650u CPUs (15W TDP). I already had a NUC using the same CPU. I was working on changes to LLVM at the time. Building it on the NUC took 20 minutes. Building it on the laptop took 35 minutes.

Better cooling allows the chip to stay at or closer to peak boost more of the time.

That CPU had peak boost of 4.2 GHz single core. In the NUC it was running at 3.2 GHz on all cores even at the end of the 20 minute build. In the laptop it was dropping quite quickly to around 2.0 GHz.

Nehalem was a pretty big advance from Core 2. I had an i7-860.

Sandy Bridge (2*) was another big jump.

Haswell  (4*) was noticeable but not massive.

Skylake (6*) was a decent advance.

Coffee Lake (8*) was an advance mostly in lower power consumption. That 15W 8650U NUC matched or even beat the 91W 6700K tower I had before it -- and while literally fitting the computer in the front pocket of my jeans.

I don't have experience with newer Intel CPUs than that as my next tower was a Zen 1+ 32 core ThreadRipper and Laptop a 6 core Zen 2 -- and the machine I actually sit at at home now is an M1 Mac Mini -- fast, always cool to the touch, always totally silent.

[Someone]

Several years ago the company I was working for supplied employees with thin laptops (Lenovo X1 Carbon) with i7-8650u CPUs (15W TDP). I already had a NUC using the same CPU. I was working on changes to LLVM at the time. Building it on the NUC took 20 minutes. Building it on the laptop took 35 minutes.

Better cooling allows the chip to stay at or closer to peak boost more of the time.
....
I don't have experience with newer Intel CPUs than that as my next tower was a Zen 1+ 32 core ThreadRipper and Laptop a 6 core Zen 2 -- and the machine I actually sit at at home now is an M1 Mac Mini -- fast, always cool to the touch, always totally silent.

We have a range of different chassis from the same brand, with the same CPU, but very different sustained performance on long complies/simulations. Exactly as you say, thermal throttling because of the platform. People also did odd things with various Macbooks to keep them out of thermal throttling as the default fan map was heavily biased towards quietness rather than performance, apparently even some of the M1 units benefit from improved cooling.

Workstations with big+slow fans and finned radiators still have a place. 4+GHz sustained AVX512 on all cores, why thank you! But newer generation high end consumer chips are even getting through that ok:
https://travisdowns.github.io/blog/2020/08/19/icl-avx512-freq.html

[Ranayna]

For completeness, where each product sits in performance order:
Atom & Pentium & Celeron (Low Performance) -> i3 (Good) -> i5 (Better) -> i7 (Best) -> i9 (Beefy) -> Xeon (Server/Workstation Class)

Generally putting Xeons at the end is not correct, at least when you are looking at raw performance.
For quite some time now, Xeons are put into similar categories as the desktop processors: Bronze -> Silver -> Gold -> Platinum. As with the desktop processors, these categories only really make sense within the same generation.

[Someone]

For completeness, where each product sits in performance order:
Atom & Pentium & Celeron (Low Performance) -> i3 (Good) -> i5 (Better) -> i7 (Best) -> i9 (Beefy) -> Xeon (Server/Workstation Class)

Generally putting Xeons at the end is not correct, at least when you are looking at raw performance.
For quite some time now, Xeons are put into similar categories as the desktop processors: Bronze -> Silver -> Gold -> Platinum. As with the desktop processors, these categories only really make sense within the same generation.

Absolutely. I have a workstation here that is a Xeon, but was middle of the road performance at the time (thankfully it was priced accordingly).

[westfw]

Have there been recent Xeons?  My only impression was that i9 replaced Xeon…
Xeon and i9 are the only ones with multiple cpu chip support, right?

[brucehoult]

Have there been recent Xeons?  My only impression was that i9 replaced Xeon…
Xeon and i9 are the only ones with multiple cpu chip support, right?

i9 doesn't support multiple processors, and many Xeons including (but not only) Xeon W don't support multiple processors.

[Berni]

The i3 i5 i7 i9 naming is just Intels marketing department giving things more friendly names for people who don't understand computers.

In the past i7 was mostly just i5 with hyperthreading while i3 was more cut down low core count stuff.

These days it's a mishmash of stuff. You can find i5 with hyperthreading or i7 without hyperthreading and i3 with a decent core count. They all use the same core architecture anyway so what matters more is the generation number. A better way is to threat all of it as an "Intel 12th gen CPU" and use benchmarks to see what performance each one gets. Offten you don't even need to get the latest generation, you might be able to get a great deal on a older generation while being almost the same speed.

[ejeffrey]

3 < 5 < 7 < 9. That's it. 

Within a particular product line and generation larger numbers are more powerful and more expensive.  The distinguishing features vary and you can't compare desktop CPUs with mobile or high performance mobile vs Ultrabook product lines.

[Someone]

3 < 5 < 7 < 9. That's it. 

Within a particular product line and generation larger numbers are more powerful and more expensive.  The distinguishing features vary and you can't compare desktop CPUs with mobile or high performance mobile vs Ultrabook product lines.

False:
i5-12600K benchmarks faster than an i7-12700 in both single and multi threaded:
https://browser.geekbench.com/processors/intel-core-i5-12600k
1857/11593
https://browser.geekbench.com/processors/intel-core-i7-12700
1823/10513

Same generation, 7 > 5, 12700 > 12600, yet performance is <

There are likely many cases of this. The performance is non-monotonic (not ordered by any of the advertising numbers) with overlaps between the "classes" within the same generation.

[coppice]

They are purely marketing terms with no technical meaning that might as well be sold as "Good", "Better", "Best".

If you go back to the first generation where they used the i3, i5 and i7 terms they meant something very specific and meaningful. Every generation since had muddied the waters a bit more. Software now has to test for every feature it might try to use against the specific chip its running on. Does an iX have feature Y? Sometimes, but you need to look up the specifics of its exact SKU or test the status registers. Instruction sets vary, especially with the most recent additions, where a wide range of fragmented additions to the instruction set might exist, in different patterns pretty randomly across the SKUs. It feels like Intel is determined to create such a mess that no software developer will try to use more of the clever features than they are absolutely forced to.

[nightfire]

Basically one has to keep two things in mind when talking CPUs:

1) Marketing makes some decision to name several branches of the product to designate them fit for a certain segment. In the early days of I3/5/7 it was simple:
i3=entry level, i5= mainstream, i7=power users. Fo enthusiasts there were special versions of the i7 with more cores etc. Later they were mostly named as i9...
In those early days, the i3 was a dual-core CPU, i5 and i7 had 4 cores, the i7 had more cache and hyperthreading and a bit higher frequency that the others.

2) Usually a complete family of CPUs is generated from the blueprint of the most powerful cpu ih the series. In the old days, where the above CPU types (Gen 2 and 3 (Sandy/Ivy bridge) were manufactured, it was simple. Basically the theoretical output would be designed as an i7, so we are talking 4 cores and 8MB of cache.
This setup would have to do a minimum of 3.4 GhZ (i7-3770), to be able to marketed as an i7 CPU.
During the course of the manufacturing process, however, lots of things can happen, that will render some portion of the silicone unusable. And now begins the magic of salvaging what is still good and sell it. So, if some problem arise at the area where the 2nd level cache sits, but the rest is still good and usable, sell it as an i5, that has less cache than the i7- and to differentiate further between the models, do not enable hyperthreading.
If a core is unusable, mark it as an i3, and do the cache in half or less (ok, with Intel caache has been associated to the respective cores, as I remember, so there is an automatic decrease in available cache in this way.
If the embedded GPU is broken, mark it as a Xeon CPU for servers that have a dedicated GPU on the mainboard.

This goes for the first generations of CPUs, later they beefed up the systems so that the target CPU would have 6 or 8 cores in later generations.

[ejeffrey]

Same generation, 7 > 5, 12700 > 12600, yet performance is <

There are likely many cases of this. The performance is non-monotonic (not ordered by any of the advertising numbers) with overlaps between the "classes" within the same generation.

You will notice on that page that the i7-12700K is considerably faster than either.  Within the product line the i7 > i5.

The i7, with or without the 'K' has more cores and more cache than the i5, but the K series are the overclockable enthusiast products with slightly higher frequencies and higher power envelope than their non-K bretheren. 

Also those benchmark scores are basically meaningless for this purpose.  It's an average of user submitted scores.  In particular, it doesn't account for system level differences in chipset, RAM type and speed.  The difference could easily be entirely due to "people with K CPUs buy higher speed memory and correctly enable the XMP profile in their BIOS".  It's likely that if you ran both CPUs in the same system with the same settings the i7-12700 would beat the i5-12600K.

For sure Intel's product line is confusing and too large with no good reason for a lot of the products and extremely frustrating choices on which features to reserve for which products. But it is still true that i7 > i5.  It's just not the whole story.

[ejeffrey]

2) Usually a complete family of CPUs is generated from the blueprint of the most powerful cpu ih the series. In the old days, where the above CPU types (Gen 2 and 3 (Sandy/Ivy bridge) were manufactured, it was simple. Basically the theoretical output would be designed as an i7, so we are talking 4 cores and 8MB of cache.
This setup would have to do a minimum of 3.4 GhZ (i7-3770), to be able to marketed as an i7 CPU.
During the course of the manufacturing process, however, lots of things can happen, that will render some portion of the silicone unusable. And now begins the magic of salvaging what is still good and sell it. So, if some problem arise at the area where the 2nd level cache sits, but the rest is still good and usable, sell it as an i5, that has less cache than the i7- and to differentiate further between the models, do not enable hyperthreading.
If a core is unusable, mark it as an i3, and do the cache in half or less (ok, with Intel caache has been associated to the respective cores, as I remember, so there is an automatic decrease in available cache in this way.
If the embedded GPU is broken, mark it as a Xeon CPU for servers that have a dedicated GPU on the mainboard.

While "binning" is certainly common to deal with speed grades and occasionally defect failures, it is rarely if ever done to the extent you describe.  Smaller parts with fewer cores and smaller cache are *usually* (there are exceptions) distinct and smaller dies.  In most manufacturing lines, a core failure is a dead part.  Some products are made to be tolerant to cache failures, but that is more often done by slightly over-provisioning and then disabling defective lines/pages, rather than cutting the cache in half for a lower grade part.

Again: there certainly have been cases of parts where defective cores, cache, or GPUs were disabled to sell as a lower tier part, but that is generally a response to a specific yield problem, it's not how Intel plans their product lines.  Sometimes they do disable perfectly good silicon to sell a part at a lower price, but this is driven by market segmentation rather than defects.  And it is normally done on either small volume parts, or where only a small amount of silicon is disabled.  For mass market chips like an i3 they want to keep the die area small in order to maximize the chips per wafer, making a chip twice the size and disabling half the cores would be wasteful.