Single thread performance increase in overclocking?

If CPU "BlaBla" has a single thread benchmark score of 2,500 at 4 GHz, how much would that single thread score increase if we overclocked it 50% (making it 6 GHz)? I assume this has to make sense.

A real example is the i7-4790K, which has the highest single thread CPU performance in the world.

This is measured at its "stock speed" or non-overclocked. Wouldn't its single threaded performance be better if it's overclocked, especially if it's overclocked to 5 GHz or higher?

How can we measure this difference?

Butter Squarm

Posted 2015-11-08T23:20:09.627

Reputation: 11

Name one CPU that has higher single threaded performance than i7-4790K. – Butter Squarm – 2015-11-09T02:29:48.463

GeekBench has it as #1 among all CPUs they test, and it's been there for years. – Butter Squarm – 2015-11-09T02:31:24.020

But you ran away, little grasshopper ... come back when stronger. – Butter Squarm – 2015-11-09T04:17:13.007

How does one measure non-overclocked single thread CPU performance? That's obviously exactly how one should measure the overclocked performance, too. And from that you get the difference. Was that your question? – zagrimsan – 2015-11-09T09:12:35.060

Answers

It would depend on the benchmark. It's not necessarily the case that clocking the CPU 50% higher will result in a 50% increase in benchmark speed. The benchmark may not be primarily CPU-limited. For example, it may be primarily memory-bound, or may be primary disk-bound. Overclocking the CPU may not result in any increase in the benchmark at all.

It's not possible to say how much faster a CPU would benchmark if overclocked, as it will depend on the benchmark.

ChrisInEdmonton

Posted 2015-11-08T23:20:09.627

Reputation: 8 110

Under ideal circumstances, how much faster then (with no external bottleneck)? – Butter Squarm – 2015-11-09T02:30:33.410

Well??????????? – Butter Squarm – 2015-11-09T06:50:32.793

Do not be so impatatient. Most people are not on here 24/7. And reread the second line of the answer and think about it. – Hennes – 2015-12-06T13:00:03.070

1Under ideal circumstances and with a benchmark that is entirely CPU-bound, the benchmark result will scale directly with clock speed. Note, though, that this begs the question. – ChrisInEdmonton – 2015-12-06T15:12:14.317

If a CPU successfully overclocked to 50% faster (let's say, 2GHz to 3GHz), the performance will only match the 50% clock increase if no other factors inhibit the performance.

Thermal throttling and voltage droop are such factors, but also CPUs can have special rules for things like Intel's Turbo Boost.

Many CPUs have different throttling profiles, not always tied to TDP.

You need adequate cooling (to avoid thermal throttling), good quality power supply, and a knowledge of other specific CPU features such as Turbo Boost.

It all comes down to how many Instructions Per Second the CPU can execute.

Phil Ricketts

Posted 2015-11-08T23:20:09.627

Reputation: 113