Help me understand intel and speeds please

Tumbleweed666

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so, my late 2013 iMac has 3.2ghz i5 processors.
Looking at the new iMac, I see it starts off with 3.0ghz i5 processors.
Are these really the same processors more than 5 years later? Or even slower if mine are 3.2 and the new ones 3.0?
Or are there multiple variants of i5 with the same name but substantially different, eg there's a 2013 i5 and a 2019 i5?
TIA
 

Steve121178

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No, the newer ones may have a the same or even lower clock speeds but are far more efficient and depending on your choice may have 6-8 cores (yours is probably quad).
 

Tumbleweed666

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Yep, mine is quad the new one would be 6 but obviously you can't parallelise all tasks, eg (afaik) Firefox woudl be stuck in one core so just dependent upon the speed ofa single core.
So are you saying that "i5" is really a top level description and there are multiple i5 variants the more recent ones of which are much faster in processing than the older ones even with differences in clock speed.
Would be good to see a real world comparison of the different iMacs I guess that will be out soon for the newer one.
 

Falhófnir

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the clock speed really has very little to do with performance when you are looking to compare between generations of chips. An 8th gen clocked at 2.5Ghz will still probably be more performant than a 5th gen clicked at 3.0Ghz (given also some other factors like the chips having the same TDP etc).

Basically what you want to look at is the single core performance (which is important when looking at system fluidity, how 'fast' everything feels doing light things like browsing) and multi core performance, which gives an indication of the overall maximum amount of power your chip can provide when it's being pushed by a heavier workload. For this it tends to be either benchmark scores like Geekbench, or actual examples of two systems rendering a video or some other task you'd be doing IRL.

In the case of the i5s you mention, it's very likely the newer one is slightly faster in single core performance (despite a slightly lower clock speed) and of course much more performant in multi core workloads, having more cores.

Edit: I have looked it up and for reference your 2013 machine has an i5-4570 - not sure what the new one has yet.
 

Tumbleweed666

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I guess the issue for someone like me not hanging on every announcement from Intel, the Apple store just says (unless i didn't dig deep enough) "i5", not "i5-4570". So on the face of it they look the same over 5+ years !
I didn't think they would be but wanted to be sure !

p.s. even going into system report on my iMac it just says "intel core i5" with no further info.
 
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Tumbleweed666

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Newer CPU's are always better the the ones they replaced. Just not by anything groundbreaking thanks to Intel's laziness.
Trouble is, Apple are not distinguishing between last years model and this. Its like Ford selling a Mustang and you just get told the new one has a 2 litre engine, which (say) is the same capacity as the model they sold five years back, no more details given.
 

Steve121178

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Trouble is, Apple are not distinguishing between last years model and this. Its like Ford selling a Mustang and you just get told the new one has a 2 litre engine, which (say) is the same capacity as the model they sold five years back, no more details given.
I don’t think Apple need to. In Intel’s defence, mainstream processors are so capable they can handle everything a user throws at them - unless you opt for the Core i9 in a MacBook Pro and soon realise Apple have done a horrific job with the thermals and find them throttling.
 

keysofanxiety

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Trouble is, Apple are not distinguishing between last years model and this. Its like Ford selling a Mustang and you just get told the new one has a 2 litre engine, which (say) is the same capacity as the model they sold five years back, no more details given.
It says 8th gen in the description on the store.

Best thing to do is use https://everymac.com/ to find the Mac with the exact CPU model, then look on https://cpubenchmark.net/ to compare the CPU score.
 

Falhófnir

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What Apple advertise really doesn't help matters here. 'core i5 and core i7' are the primary upsell for their upgrade trees, but they also charge more for higher clocked versions of (particularly the i7) so that's probably the only reason they even note that any more. They could do with revisiting this, the core counts and threads are relevant (though not overwhelmingly so to most people) inumber is branding more than anything, though does tend to roughly denote a hierarchy within a specific generation of a specific type of chip (but obviously for that to mean anything you have to be at least vaguely familiar with Intel's arcane product strategy). For example you can have a core i7-7820HQ in the surface studio - which will be marketed as 'intel core i7'. Only, its a 7th generation laptop chip that is no more powerful than the i3-8100 in the 4K iMac, let alone the i5 version (these are proper desktop chips) confusing, right? It's partly intel's fault too for having a nonsensical naming scheme, hopefully Apple will come up with something saner if they start making their own ARM mac chips.

I guess the basics you need to know are:
Proper desktop chip? (check for all iMacs)
Latest generation? (yes, 8th and 9th gen insofar as they are available)
i7>i5>i3? (Yes, they are within the same product family*)

*though some are 9th gen and some 8th, doesn't really matter here, but yeah. Confusing again.

Newer CPU's are always better the the ones they replaced. Just not by anything groundbreaking thanks to Intel's laziness.
I guess you just kind of have to trust in this logic (though not always the case as with the mac mini moving to dual core laptop chips for the previous generation).
 

topgunn

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You can go to Geekbench Mac Browser to get a good idea of how powerful one machine is compared to another. Keep in mind, these are synthetic benchmarks and real world performance may vary.

In your case, the CPU on your 2013 iMac scores 3966 on single core and 11324 on multicore. By comparison, the Mac mini with the same i5-8500 3.0GHz CPU as the base model 27" iMacs scores a 5155 on single core and 20295 on multicore. Using these figures, the new 3.0GHz processor is 30% faster in single core and 80% faster in multicore tasks than your 3.2GHz i5 from 2013.

This is because the IPC (instructions per cycle) is much higher on the newer chips. Basically, this is how many operations can be performed every time the cycle comes around. Since the clock speed is lower on the new chips, the cycle comes around less often but more is done when it does come around.
 

quagmire

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The 8500 also has a higher turboboost clock of 4.1 Ghz than the 4570's 3.6 Ghz. So architecture efficiency improvements plus a 500 Mhz boost when it runs on 1-2 cores( if thermally able) explains why the 8500 is faster even in single threaded applications over the 4570.
 

alien3dx

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so, my late 2013 iMac has 3.2ghz i5 processors.
Looking at the new iMac, I see it starts off with 3.0ghz i5 processors.
Are these really the same processors more than 5 years later? Or even slower if mine are 3.2 and the new ones 3.0?
Or are there multiple variants of i5 with the same name but substantially different, eg there's a 2013 i5 and a 2019 i5?
TIA
the processor is not the same but only extra a bit .what most important is ram and hardisk speed as ssd.Unless you do complex calculation not much diff at all.
 

adamjackson

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Clock speed is mostly dead. My 2012 MacBook Pro was 2.7Ghz. My 2018 MacBook Pro is 2.9Ghz and it's the highest end one they make but despite only 300 megahertz on paper in 6-7 years, there's such a massive difference.

https://cpu.userbenchmark.com/Compare/Intel-Core-i9-8950HK-vs-Intel-Core-i7-3820QM/m486215vsm4339

The new CPU is 52% faster effectively thanks to more cores while operating at the exact same wattage. It's more important now to have a newer process delivering a smaller chip that's just as energy efficient with at least 50% faster specs (in some cases 70% faster).

The CPU gains year over year are way smaller now but we're still getting Gaines.
 

Tumbleweed666

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Thanks all. interesting that even after 5 years raw cpu is only 30-80% faster.
Of course, faster memory and SSDs will also help (I do have an SSD but I understand new SSDs are faster)
 
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macduke

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Thanks all. interesting that even after 5 years raw cpu is only 30-80% faster.
Of course, faster memory and SSDs will also help (I do have an SSD but I understand new SSDs are faster)
Yeah, Moore's law has been drawing to a close. This is why Apple has been able to catch up to Intel with their A-series on the iPad Pro compared to laptops, and why everyone says Apple's chip design team is so impressive, and also why many people expect Apple to start transitioning the Mac to Apple CPUs in the coming years.

You need to stop thinking about CPUs in terms of GHz and look at things like turboboost, hyper threading, L3 cache, single vs. multicore score comparisons, etc. It's way more complicated than it used to be. I remember back when I used to build PCs it was like "The 1.9GHz Pentium 4 is faster than the 1.5GHz Pentium 4" and it was really easy to calculate the scale in performance and the cost per MHz increase. Now you have to look at a bunch of benchmarks and consider all the other specs.
 
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