Author Topic: Lies, damned lies and benchmarks  (Read 182 times)

CommuteTooFar

  • Inadequate Randonneur
Lies, damned lies and benchmarks
« on: February 04, 2020, 01:03:14 pm »
A few years ago AMD designed a new architecture called Bulldozer. This was tested and subsequently ridiculed as hopeless. The top chip Fx-3850 should have competed with the contemporary i7 but it was built on a less dense chip process so ended up as a competitor to the i5-2500. The benchmarks were done. In those days the benchmarkers held the false notion that if you use a very fast graphics card and low (VGA) resolutions you will reveal the performance of the cpu.
Every gamer read the benchmarks and when they felt they needed a better machine chose the Goldilocks priced i5-2500.

Modern times. Neither of these two chips are relevant today but sometimes appear in benchmarks.
Modern benchmarking practice is to show best performance so a 'good' tester will test at 1080p, 1440, 4K with highest graphics quality.
They also test the older processors to see where they are with modern games. In this new difficult world the fx-3850 has jumped ahead of the i5-2500.

What has happened here?  Quite simple, in the harsh modern games the performance is limited by the processor. Game engines are compiled and optimised for Intel's cpu architecture.
So if you look at a lesser load the Intel chip is putting everything into. An activity monitor will show 100% on one or more threads.  Poor old Bulldozer is running at 80%.
So when a bigger challenge is offered to the processor the i5 cannot go any faster. But the fx-3850 has another 20% to give and outperforms the i5-2500. It seems that Bulldozer was not such a bad design after all.

I am not suggesting people who chose the i5-2500 got it wrong. Clearly it ran contemporary games and resolutions better than the fx-3850.

Currently most commentators are suggesting the i9-9900KF is the best processor for gaming.  Are they making the same error again? The price equivalent AMD part is the 12-core Ryzen 9 3900. This may become very obvious this year.
In the next few months Sony and Microsoft are launching new consoles. Both are using custom AMD Ryzen 3000 chips and Navi graphics. It seems likely that game companies will start optimising for AMD and more threads. The conclusions from the benchmarks will change miraculously