Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

10-core i9-10900F desktop CPU lags behind 8-core Ryzen 9 4900HS mobile APU

notebookcheck.net

Post reply on HN
Print view View original

21–30 of 148 posts

Re: 10-core i9-10900F desktop CPU lags behind 8-core Ryzen 9 4900HS mobile APU

#21

Post by rasz »

briffle wrote: post #2

Does this new intel CPU have 'fixes' for all issues like spectre and meltdown, where you were supposed to turn off hyperthreading for better security? I'm just curious if the fixes for those (and other similar vulnerabilities) are starting to make their way into silicon, but also that the fixes recommended usually slow cpu's down quite a bit too.

Intel "fixes" so far has been microcode level detectors for particular proof of concepts submitted by researchers. Makeup on a pig.

https://www.nytimes.com/2019/11/12/technology/intel-chip-fix...

Re: 10-core i9-10900F desktop CPU lags behind 8-core Ryzen 9 4900HS mobile APU

#22

Post by rasz »

AnotherGoodName wrote: post #6
leetcrew wrote: post #3

this doesn't quite pass the smell test. I can't quite tell if there's a way to filter out results from overclocked parts in geekbench, but it looks like these results for the i9-10900F are significantly lower than typical results for a stock i9-9900K. hard to believe they would do worse on the same process with more cores.

It also doesn't pass the smell test in that the single core performance is higher than the Ryzen 4900 and it also has both more cores and more threads yet it is far behind on multicore performance? Likely some thread affinity issue that just needs a patch.

throttling

Re: 10-core i9-10900F desktop CPU lags behind 8-core Ryzen 9 4900HS mobile APU

#23

Post by kllrnohj »

briffle wrote: post #2

Does this new intel CPU have 'fixes' for all issues like spectre and meltdown, where you were supposed to turn off hyperthreading for better security? I'm just curious if the fixes for those (and other similar vulnerabilities) are starting to make their way into silicon, but also that the fixes recommended usually slow cpu's down quite a bit too.

> Does this new intel CPU have 'fixes' for all issues like spectre and meltdown

It's worth noting that Spectre-V1 is likely to be with us for many many years. CPUs have so far only shown interest in addressing spectre when spectre is crossing process or ring boundaries. In-process spectre leaks (so variant 1, Bounds Check Bypass) are currently not really being considered a problem in the CPU's eyes. No privilege boundaries were crossed, therefore not a bug.

As in, secure in-process sandboxing seems to just be dead. Or left as an exercise for the embedding code to figure out how to in some way handle with no CPU support.

Re: 10-core i9-10900F desktop CPU lags behind 8-core Ryzen 9 4900HS mobile APU

#24

Post by nottorp »

Hmm I need some schooling please:

"The TDP for the latter part is 35 W while the i9-10900F is listed at 65 W, but being an Intel desktop processor that just reflects the TDP for the base clock, with much higher energy demands required for higher clocks (e.g. maximum PL1 has been recorded at 170 W)."

So where do I find the actual maximum power consumption on recent desktop CPUs then? Do I set a limit in the BIOS? Do I read each and every review to see what they measured?

Pointers to relevant links very much appreciated, thankee sai.

Re: 10-core i9-10900F desktop CPU lags behind 8-core Ryzen 9 4900HS mobile APU

#26

Post by rowanG077 »

nottorp wrote: post #24

Hmm I need some schooling please: "The TDP for the latter part is 35 W while the i9-10900F is listed at 65 W, but being an Intel desktop processor that just reflects the TDP for the base clock, with much higher energy demands required for higher clocks (e.g. maximum PL1 has been recorded at 170 W)." So where do I find the actual maximum power consumption on recent desktop CPUs then? Do I set a limit in the BIOS? Do I…

You can't find it. Intel has obscured the measurement too much. AMD is guilty of this as well but on a much smaller scale then Intel.

Re: 10-core i9-10900F desktop CPU lags behind 8-core Ryzen 9 4900HS mobile APU

#27

Post by nottorp »

rowanG077 wrote: post #26
nottorp wrote: post #24

Hmm I need some schooling please: "The TDP for the latter part is 35 W while the i9-10900F is listed at 65 W, but being an Intel desktop processor that just reflects the TDP for the base clock, with much higher energy demands required for higher clocks (e.g. maximum PL1 has been recorded at 170 W)." So where do I find the actual maximum power consumption on recent desktop CPUs then? Do I set a limit in the BIOS? Do I…

You can't find it. Intel has obscured the measurement too much. AMD is guilty of this as well but on a much smaller scale then Intel.

Sheesh. So the only way is to settle on a few cpu models and search for reviews that have measured the actual power consumption?

Re: 10-core i9-10900F desktop CPU lags behind 8-core Ryzen 9 4900HS mobile APU

#28

Post by leeter »

nottorp wrote: post #24

Hmm I need some schooling please: "The TDP for the latter part is 35 W while the i9-10900F is listed at 65 W, but being an Intel desktop processor that just reflects the TDP for the base clock, with much higher energy demands required for higher clocks (e.g. maximum PL1 has been recorded at 170 W)." So where do I find the actual maximum power consumption on recent desktop CPUs then? Do I set a limit in the BIOS? Do I…

> So where do I find the actual maximum power consumption on recent desktop CPUs then?

Unfortunately you do this by putting it on a motherboard and and generally putting an amp meter on the 12v EPS rail. Either that or just power from wall. The CPU vendors have worked really hard to hide this. Mostly because for most people it's largely irrelevant these days as the CPU will scale to cooling and power delivery. There are some limits though.

Re: 10-core i9-10900F desktop CPU lags behind 8-core Ryzen 9 4900HS mobile APU

#29

Post by leeter »

nottorp wrote: post #27
rowanG077 wrote: post #26

Earlier quoted context omitted.

You can't find it. Intel has obscured the measurement too much. AMD is guilty of this as well but on a much smaller scale then Intel.

Sheesh. So the only way is to settle on a few cpu models and search for reviews that have measured the actual power consumption?

Even that is specific to that chip/mobo/PSU/Case/CPU cooler setup. So unless you match what was used in the article your mileage will vary a lot.

Re: 10-core i9-10900F desktop CPU lags behind 8-core Ryzen 9 4900HS mobile APU

#30

Post by kllrnohj »

leetcrew wrote: post #3

this doesn't quite pass the smell test. I can't quite tell if there's a way to filter out results from overclocked parts in geekbench, but it looks like these results for the i9-10900F are significantly lower than typical results for a stock i9-9900K. hard to believe they would do worse on the same process with more cores.

I think the key thing you've missed is the i9-10900F is a 65W part, while the i9-9900K is 95W.

Given both are on basically the same manufacturing process with basically the same architecture, it's really not surprising the i9-10900F isn't keeping up with the i9-9900K in max load scenarios. Having 50% more power easily makes up for 20% fewer cores.

Which is then also why the 4900HS is able to be so competitive with it. It's a 35W part but on a more advanced manufacturing node.

And although TDP is a made up number that has very little meaning, it is roughly what the CPU will settle into when the boost duration has exceeded. So eventually under a constant multithreaded workload the 9900K and 10900F should settle in to their 95W and 65W limits respectively.

Post reply on HN