5 ms·

The very first graph (Cinebench R15) is wrong. i7-8700K does not score 3314 or even 2515 on this benchmark [1]. i7-7700K numbers are also way off. Not sure what

The very first graph (Cinebench R15) is wrong. i7-8700K does not score 3314 or even 2515 on this benchmark [1]. i7-7700K numbers are also way off. Not sure what happened here, but I can't take any other measurement they published seriously. This is more useful: https://www.phoronix.com/scan.php?page=article&item=sandy-fx-zombieload&num=3 https://www.phoronix.com/scan.php?page=article&item=sandy-fx... If you're using an overclockable workstation CPU, the good news is that turning SMT off gives you additional ~200Hz of overclocking headroom. Modern Intel chips are thermally limited when overclocking and turning SMT off makes them run a bit cooler. My i9-7900X overheats over 4.4Ghz, but with SMT off it's comfortable at 4.7Ghz on air (Noctua D15). [1] https://www.guru3d.com/news-story/intel-core-i7-8700k-benchmarks.html https://www.guru3d.com/news-story/intel-core-i7-8700k-benchm...

Yetanfou 7y ago
> the good news is that turning SMT off gives you additional ~200Hz of overclocking headroom That'd be 200 MHz, not 200 Hz?
- rzzzt 7y ago
  Not on my MOS 6502!
  - monocasa 7y ago
    There's some 6502 compatible cores that are around 200MHz these days.
  - duskwuff 7y ago
    The concept of a hyperthreaded 6502 is intriguing, and I wish to subscribe to your newsletter...
  - tinus_hn 7y ago
    The 6502 runs at around 1MHz so even on that 200Hz would be irrelevant.
- old-gregg 7y ago
  Good catch, yes. :)
mappu 7y ago
> I can't take any other measurement they published seriously. Here's another problem with the article: > Microsoft is pushing out OS-level updates [...] However, this doesn’t mitigate the problem entirely, for that we need motherboard BIOS updates and reportedly Intel has released the new microcode to motherboard partners. However as of writing no new BIOS revisions have been released to the public. That's wrong - microcode updates can be successfully applied by either the OS or by the early-boot firmware, you do not need a BIOS update (just apt update intel-microcode).
- p1mrx 7y ago
  They probably ran the benchmarks on Windows. Is it possible to customize the microcode version on Windows without a patch from Microsoft?
  - gmueckl 7y ago
    No. I have to look it up to be certain but I believe that MS did not want to patch CPU microcode during boot and tried to leave that to the firmware. But - I may be wrong here - this stance changed with Spectre and Meltdown and Windows does indeed patch microcode during boot on affected CPUs. However, I don't think there is a way to apply a user-specified patch. The update has to come from MS.
  - ChrisOboe 7y ago
    Yes,VMware has a free (as in beer) windows tool to update (downgrading is not possible) the microcode.
    - duskwuff 7y ago
      > downgrading is not possible Sure it is. I've done it myself. Microcode is stored in volatile memory on the CPU. Updates are applied on boot, every boot. "Downgrading" is as simple as not applying updates, or applying an older update.
      - shawnz 7y ago
deleted 7y ago
[deleted]
Syzygies 7y ago
Bingo. Hyperthreading does not pay for itself, overclocking. Period. End of discussion. I turn it off, or buy chips without it.
- gambiting 7y ago
  Overlocking is not an option on 99% of laptops.
justinclift 7y ago
The text around it says Cinebench R20 too. Guessing both were tested, and the wrong data set was pasted into the article. "First off we have Cinebench R20 results ..."
- deleted 7y ago
  [deleted]
martinpw 7y ago
There is an R20 8700k score listed here which is close to the one quoted in the Techspot article (3372 vs 3314): https://www.geeks3d.com/20190306/tested-cinebench-r20-cpu-benchmark-released/ https://www.geeks3d.com/20190306/tested-cinebench-r20-cpu-be... So Techspot numbers are fine, just a typo on version of benchmark, should say R20 on graph not R15.
emn13 7y ago
Just note that the perf loss is 20-40% in their benchmarks, so in your case, you'd need to bump that 4.4Ghz to 5.5-73.GHz, which is a tall order. In any case, the article is worst-case FUD-like nonsense. No idea what the eventual perf loss will be, but it's a safe bet it'll be less than that. Consider that it's likely safe enough for 99% of usages for the OS to allocate CPU cores to processes in pairs, and that would incur only a small penalty. And something smarter is almost certainly possible, too.

Yetanfou 7y ago

> the good news is that turning SMT off gives you additional ~200Hz of overclocking headroom That'd be 200 MHz, not 200 Hz?

rzzzt 7y ago
Not on my MOS 6502!
- monocasa 7y ago
  There's some 6502 compatible cores that are around 200MHz these days.
- duskwuff 7y ago
  The concept of a hyperthreaded 6502 is intriguing, and I wish to subscribe to your newsletter...
- tinus_hn 7y ago
  The 6502 runs at around 1MHz so even on that 200Hz would be irrelevant.
old-gregg 7y ago
Good catch, yes. :)

mappu 7y ago

> I can't take any other measurement they published seriously. Here's another problem with the article: > Microsoft is pushing out OS-level updates [...] However, this doesn’t mitigate the problem entirely, for that we need motherboard BIOS updates and reportedly Intel has released the new microcode to motherboard partners. However as of writing no new BIOS revisions have been released to the public. That's wrong - microcode updates can be successfully applied by either the OS or by the early-boot firmware, you do not need a BIOS update (just apt update intel-microcode).

p1mrx 7y ago
They probably ran the benchmarks on Windows. Is it possible to customize the microcode version on Windows without a patch from Microsoft?
- gmueckl 7y ago
  No. I have to look it up to be certain but I believe that MS did not want to patch CPU microcode during boot and tried to leave that to the firmware. But - I may be wrong here - this stance changed with Spectre and Meltdown and Windows does indeed patch microcode during boot on affected CPUs. However, I don't think there is a way to apply a user-specified patch. The update has to come from MS.
- ChrisOboe 7y ago
  Yes,VMware has a free (as in beer) windows tool to update (downgrading is not possible) the microcode.
  - duskwuff 7y ago
    > downgrading is not possible Sure it is. I've done it myself. Microcode is stored in volatile memory on the CPU. Updates are applied on boot, every boot. "Downgrading" is as simple as not applying updates, or applying an older update.
    - shawnz 7y ago

deleted 7y ago

[deleted]

Syzygies 7y ago

Bingo. Hyperthreading does not pay for itself, overclocking. Period. End of discussion. I turn it off, or buy chips without it.

gambiting 7y ago
Overlocking is not an option on 99% of laptops.

justinclift 7y ago

The text around it says Cinebench R20 too. Guessing both were tested, and the wrong data set was pasted into the article. "First off we have Cinebench R20 results ..."

deleted 7y ago
[deleted]

martinpw 7y ago

There is an R20 8700k score listed here which is close to the one quoted in the Techspot article (3372 vs 3314): https://www.geeks3d.com/20190306/tested-cinebench-r20-cpu-benchmark-released/ https://www.geeks3d.com/20190306/tested-cinebench-r20-cpu-be... So Techspot numbers are fine, just a typo on version of benchmark, should say R20 on graph not R15.

emn13 7y ago

Just note that the perf loss is 20-40% in their benchmarks, so in your case, you'd need to bump that 4.4Ghz to 5.5-73.GHz, which is a tall order. In any case, the article is worst-case FUD-like nonsense. No idea what the eventual perf loss will be, but it's a safe bet it'll be less than that. Consider that it's likely safe enough for 99% of usages for the OS to allocate CPU cores to processes in pairs, and that would incur only a small penalty. And something smarter is almost certainly possible, too.