3 ms·

> I can't take any other measurement they published seriously. Here's another problem with the article: > Microsoft is pushing out OS-level updates [...] Howe

by 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
      Perhaps they meant that downgrading is not possible without a reboot.
      - quintushoratius 7y ago
        Loading microcode on a CPU (without patching the firmware) takes effect immediately. The update is lost immediately upon reboot and must be reapplied each time.
        shawnz 7y ago
        Right, but can you load an older microcode after a newer microcode has already been loaded, without rebooting?

by mappu 7y ago

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
    Perhaps they meant that downgrading is not possible without a reboot.
    - quintushoratius 7y ago
      Loading microcode on a CPU (without patching the firmware) takes effect immediately. The update is lost immediately upon reboot and must be reapplied each time.
      - shawnz 7y ago
        Right, but can you load an older microcode after a newer microcode has already been loaded, without rebooting?