6 ms·

The headline is completely bogus. The author switched both the filesystem from HFS+ to APFS and the Meltdown patch was applied. This effect cannot be attributed

by raimue 9y ago

The headline is completely bogus. The author switched both the filesystem from HFS+ to APFS and the Meltdown patch was applied. This effect cannot be attributed to just one of them without further testing.

netgusto 9y ago
I applied the patched on both my systems (iMac 2013 core i7 on Sierra under HFS+ that was upgraded to High Sierra for the occasion, and a MacBookPro 2017 already on High Sierra under APFS), and I can confirm that both my systems are seriously and objectively slowed down, 4 days after the patch now. From what I could observe, applications taking the most serious hit are electron based (like VSCode, that went from smooth as silk to mildly sluggish) and Safari. Docker on mac has also taken a hit, although I couldn't quantify it objectively.
- mastax 9y ago
  Interesting. I had thought about game load times. Most use large agglomerations and shouldn't be too affected. Some games do load small loose files and would be slowed significantly. I suppose the same applies to desktop applications. Most use a large executable with maybe a few dlls. Electron and Python applications that ship as source or bytecode will be much more affected.
- jaaames 9y ago
  Ok so I'm not completely insane, everything felt like molasses this week and that's why.
  - throwawaysecops 9y ago
    Then it's no coincidence that insanity is slowing things down to effect the ongoing illusion of security.
mpweiher 9y ago
You did read the bit where I accounted for APFS, right? And also that the raw, combined difference was 4x, not 3x?
- raimue 9y ago
  You are comparing the maximum write data rate of HFS+ and APFS with the write rate of mkfile with small blocks. I do not think you can assume that the write rate in the filesystem stays the same if you decrease the block size. The expensive operation might be the block allocation that is easy for larger blocks, but for small blocks it might try to squeeze them in somewhere to avoid fragmentation. Yes, syscalls are expensive and most likely became very expensive with the Meltdown patch. Even more so on OS X, where filesystem drivers are running in their own process. I am not arguing against performance drops due to both Meltdown path or APFS, but I do not think your data shows the conclusion you are using in the headline.
  - mpweiher 9y ago
    You didn't read the headline. Or the article. Or the referenced (linked) article. Seriously: a rebuttal of what you wrote is easy, but amounts to rephrasing the article.
    - rudedogg 9y ago
      Was there something that prevented testing HFS+ vs. HFS+?
      - loeg 9y ago
        Possibly: > As part of the upgrade process, the macOS High Sierra installer will automatically convert an SSD to the new APFS https://blog.macsales.com/42884-is-it-possible-not-to-convert-to-apfs-when-upgrading-to-high-sierra https://blog.macsales.com/42884-is-it-possible-not-to-conver...
    - Girlang 9y ago
      Mac Zealots will believe what they want. Ignore them.

by raimue 9y ago

netgusto 9y ago

I applied the patched on both my systems (iMac 2013 core i7 on Sierra under HFS+ that was upgraded to High Sierra for the occasion, and a MacBookPro 2017 already on High Sierra under APFS), and I can confirm that both my systems are seriously and objectively slowed down, 4 days after the patch now. From what I could observe, applications taking the most serious hit are electron based (like VSCode, that went from smooth as silk to mildly sluggish) and Safari. Docker on mac has also taken a hit, although I couldn't quantify it objectively.

mastax 9y ago
Interesting. I had thought about game load times. Most use large agglomerations and shouldn't be too affected. Some games do load small loose files and would be slowed significantly. I suppose the same applies to desktop applications. Most use a large executable with maybe a few dlls. Electron and Python applications that ship as source or bytecode will be much more affected.
jaaames 9y ago
Ok so I'm not completely insane, everything felt like molasses this week and that's why.
- throwawaysecops 9y ago
  Then it's no coincidence that insanity is slowing things down to effect the ongoing illusion of security.

mpweiher 9y ago

You did read the bit where I accounted for APFS, right? And also that the raw, combined difference was 4x, not 3x?

raimue 9y ago
You are comparing the maximum write data rate of HFS+ and APFS with the write rate of mkfile with small blocks. I do not think you can assume that the write rate in the filesystem stays the same if you decrease the block size. The expensive operation might be the block allocation that is easy for larger blocks, but for small blocks it might try to squeeze them in somewhere to avoid fragmentation. Yes, syscalls are expensive and most likely became very expensive with the Meltdown patch. Even more so on OS X, where filesystem drivers are running in their own process. I am not arguing against performance drops due to both Meltdown path or APFS, but I do not think your data shows the conclusion you are using in the headline.
- mpweiher 9y ago
  You didn't read the headline. Or the article. Or the referenced (linked) article. Seriously: a rebuttal of what you wrote is easy, but amounts to rephrasing the article.
  - rudedogg 9y ago
    Was there something that prevented testing HFS+ vs. HFS+?
    - loeg 9y ago
      Possibly: > As part of the upgrade process, the macOS High Sierra installer will automatically convert an SSD to the new APFS https://blog.macsales.com/42884-is-it-possible-not-to-convert-to-apfs-when-upgrading-to-high-sierra https://blog.macsales.com/42884-is-it-possible-not-to-conver...
  - Girlang 9y ago
    Mac Zealots will believe what they want. Ignore them.