Why older CPUs perform better?

-2

By "perform" I mean have better scores on websites like cpuboss.com or userbenchmark.com. Is that a bad metric, perhaps?

An example: my old laptop has i7 3632QM. New similarly priced laptops have [i7 6500U](i7 6500U). Here are the comparison: cpuboss.com comparison for Intel Core i7 6500U vs. Intel Core i7 3632QM

Note the advantage in the single core test.

Then I compared it to a modern quad core (i7 6700HQ): cpuboss comparison of Intel Core i7 6700HQ vs. Intel Core i7 3632QM

Now the score is closer, but the new processor consumes even more energy, 14 nm notwithstanding.

I'm quite confused, it makes it seem like there was no progress in 5 years.

mathquest

Posted 2016-11-06T23:39:03.180

Reputation: 7

5The i7-3632QM CPU was a performance-oriented CPU typically used in workstation-class laptops (notice the QM designation, these babies were supposed to be comparable to desktop CPUs). The i7-6500U is specifically engineered to consume very little power (notice the U desgination, meaning 'ultra-low power') while providing good-enough performance for office/web/media-consumption workloads. You're comparing apples and oranges here, and 5 years is not actually that long in CPU evolution (the era of massive performance gains between CPU generations is long gone). – misha256 – 2016-11-06T23:57:39.783

@misha256 what about i7-6700HQ, it consumes even more energy seemingly having no advantage. There must be some tasks where new CPUs are better, otherwise I don't see why anybody buys them. – mathquest – 2016-11-07T00:59:42.177

@misha256: wouldn't it be a better idea to have your comment as an answer as comments are rather reserved for information and or clarity on questions and answers? – nyedidikeke – 2016-11-07T01:01:14.383

@bors "no advantage" is not true, benchmarks do indicate some advantage... but not worth the money IMO. It is well known, among enthusiasts, that pure performance improvements since Intel's Sandy/Ivy Bridge have been minimal. Sure, newer CPUs perform a little bit better, and they have some extra features that modern OS' can utilize (e.g. accelerated cryptography and video encoding/decoding), and the "U" series CPUs are truly awesome in terms of power consumtpion, but that's about it. This is the world be live in today, mainstream CPUs are just not getting better as fast as they used to. – misha256 – 2016-11-07T01:51:37.153

@nyedidikeke this is a difficult question to answer authoritively and with good references so I'm just sticking to comments. – misha256 – 2016-11-07T01:53:45.710

@misha256 thank you for your answer. It's interesting about the slowed down growth. I hope the increasing complexity of software would not make the user experience worse with time. – mathquest – 2016-11-07T14:50:14.903

In this case: Because apples are not oranges, frankly. – music2myear – 2016-11-07T17:14:13.053

Answers

You are confused by the comparison, because the comparison you looked at is invalid.

CPUBoss, and the database it uses (Primate Labs) have a severe problem with the GeekBench 3 AES results. Scores from several entire generations of Intel CPUs have been stored in the database with the wrong units.

The actual speed is 2 GB/s, but the score shows as 2 TB/s, which is an impossibility (not even SIMD register access, with no calculations, has that much bandwidth).

The reality is that the speed of the i7-3632 is one-half of the i7-6700, not 500 times higher.

I've used the contact link to report these widespread errors multiple times, but they haven't done anything to fix their database (they may have fixed a couple of individual numbers but haven't bothered doing a query to find all the impossible values). I suggest you use a better comparison site until they get it straightened out.

In addition, there's a negative (!!) score listed on the T-Rex score. Presumably this is a placeholder for "not tested", but missing results properly show up as "n.d." (can be seen on other CPU pages), suggesting that this too is being averaged into the overall rating.

As the saying goes, "garbage in, garbage out"... and the performance, performance/$, and performance/W comparisons are all garbage.

Ben Voigt

Posted 2016-11-06T23:39:03.180

Reputation: 6 052

the old CPU is faster because it is a Quad Core i7 with Hyperthreading so that you get 8 logical cores, while the i7 6500U is only a Dual Core CPU with Hyperthreading, so you have 4 logical cores.

So yes, the Quad core is faster compared to the Dual Core. Also the U stands for ultra book, so those U CPUs are used in ultra books, where the performance is not that important, here those CPUs are used because you have a longer battery life, because the U CPUs use less power and generate less heat compared to the faster quad core CPUs.

magicandre1981

Posted 2016-11-06T23:39:03.180

Reputation: 86 560