Intel Announces 8 Core I9-9900KS: Every Core at 5Ghz, All the Time

Re:Intel Announces 8 Core I9-9900KS: Every Core at 5Ghz, All... by gchamonlive on Sunday May 26, 2019 @12:58PM (#20015898)

I believe Intel processors can't boost all cores. At least some tests I have done with my notebook processor (i7 8550u - 4c8t) with `stress -c n`, being n the number of processors, show that for n > 1 the processor doesn't reach 4ghz, only about 3.7ghz, while the package temps are still at around 70 °C. Only a single core on full load reaches 4ghz before throttling.

[ Parent | on HN ]

Re:Intel Announces 8 Core I9-9900KS: Every Core at 5Ghz, All... by mackal on Sunday May 26, 2019 @01:34PM (#20016163)

This is entirely configurable. They generally don't do all core == max boost for power consumption reasons (and I assume yield would be pretty low on chips that can do this)

Desktop chips also generally don't have any AVX offset, which is almost always required for 5 GHz all core.

[ Parent | on HN ]

Re:Intel Announces 8 Core I9-9900KS: Every Core at 5Ghz, All... by shereadsthenews on Sunday May 26, 2019 @01:02PM (#20015923)

Yes, there's a table in the firmware that can tell you the maximum speed with N active cores. This one though has the same speed for all values of N.

[ Parent | on HN ]

Re:Intel Announces 8 Core I9-9900KS: Every Core at 5Ghz, All... by clarry on Sunday May 26, 2019 @01:02PM (#20015930)

> I believe Intel processors can't boost all cores.

And that's exactly what shereadsthenews's point is. They can't boost all cores, and they are not boosting any core beyond the all-core capacity if it's truly a CPU that runs at 5 GHz all the time.

[ Parent | on HN ]

Re:Intel Announces 8 Core I9-9900KS: Every Core at 5Ghz, All... by XMPPwocky on Sunday May 26, 2019 @01:16PM (#20016026)

Turbo Boost can certainly apply to all cores- the limits you hit are TDP and time based, there, not strictly thermal.

So, for example, my old laptop CPU would clock itself up to 2.7GHz on all cores... well, okay, it was a dual core, so that's not saying much, but still. But it'd only maintain that boost for a few seconds- under sustained load it dropped down to 2.5. This wasn't because of thermals, but rather because 2.7GHz was a Turbo Boost frequency, and once the PPL timer runs out...

[ Parent | on HN ]

Re:Intel Announces 8 Core I9-9900KS: Every Core at 5Ghz, All... by XMPPwocky on Sunday May 26, 2019 @01:22PM (#20016072)

And to explain why they don't have, say, one core boost to 5.1GHz...well, let's see what siliconlottery says.

> As of 3/16/19, the top 38% of tested 9900Ks were able to hit 5.0GHz or greater.

> As of 3/16/19, the top 8% of tested 9900Ks were able to hit 5.1GHz or greater.

So, Intel'd cut their yield by more than a factor of four if they only let parts that could hit 5.1 into this bin. For a 2% single-core performance boost...

[ Parent | on HN ]

Re:Intel Announces 8 Core I9-9900KS: Every Core at 5Ghz, All... by mackal on Sunday May 26, 2019 @01:35PM (#20016176)

I think those numbers are for chips that can 5.1 GHz all core though, which is probably a lot less than 5.1 GHz single core.

[ Parent | on HN ]

Re:Intel Announces 8 Core I9-9900KS: Every Core at 5Ghz, All... by XMPPwocky on Sunday May 26, 2019 @02:33PM (#20016568)

As far as I know, K-series parts don't support binning of individual cores- if you have one bad core that'll only hit 5.0, 1-core turbo to 5.1 will still result in the OS scheduler periodically picking that core to use, it clocking up to 5.1, and problems resulting.

Might be wrong, though.

[ Parent | on HN ]

Re:Intel Announces 8 Core I9-9900KS: Every Core at 5Ghz, All... by wtallis on Sunday May 26, 2019 @06:09PM (#20017882)

Intel's Turbo Boost 3.0 [1] was their attempt to take advantage of the fact that some cores on a chip can clock higher than others. It does not work well in practice, because it requires too much collaboration with motherboard and OS vendors. This feature is not available on their desktop platform, which the i9-9900KS uses.

[1] https://www.intel.com/content/www/us/en/architecture-and-tec...

[ Parent | on HN ]

Re:Intel Announces 8 Core I9-9900KS: Every Core at 5Ghz, All... by rzzzt on Sunday May 26, 2019 @01:07PM (#20015972)

XTU allows setting different turbo multipliers for 1-4 active cores (but the difference from the nominal clock speed typically gets smaller as more cores become active).

[ Parent | on HN ]