I doubt it, that SHUF bug is an old one that was fixed with 20191112 general release of Intel microcode.

Incomplete fixes for previous MDS mitigations (VERW)

Firmware changes released on 14 May 2019 for the initial round of MDS overloaded an instruction that was intended to clear a buffer to ensure information would not leak to the end user. This fix modified four of the instructions to perform additional functionality to be used by the operating systems in an attempt to mitigate the flaw. These instructions were:

VERW instruction
L1D_FLUSH instruction
RSM (Return from System Management mode)
SGX Enter and SGX Exit. (Secure Enclave Enter and Exit).

The VERW and L1D_FLUSH commands were used by operating system vendors to instruct the firmware running on the affected processors to overwrite buffer values that can be used in the various MDS attack set.

The flaw is that the L1D buffers were incorrectly cleared and not all bits of the buffer were set to zero. Some parts (bits 16-31 and 48-63) of the buffer were restored to their last known value prior to clearing shortly after they were set to be cleared.

This allows a side-channel into the partially shared data by the system, but to a lesser extent than previous MDS exposure.

A local attacker would need to execute an MDS style attack on systems to gather intelligence on the system. The attack reliability is believed to be considerably less reliable than previous MDS style attacks.

This issue requires a microcode update and it is expected to have no performance impact or change.

Also the SHUF bug you are correct that was fixed with 20191112 but the haswell microcode 27 is from may. So i believe that i am correct but who knows.

SHUF was fixed on multiple processor generations and none of them have bit 9 defined. It was a silent fix that the OS does not check. Having an undocumented new CPUID flag is for the OS to see that something important has changed/been implemented/guaranteed-not-affected.

Has anyone compared microcode 28 to previous versions.I have MC.27 on my I7-4790K and wonder if its worth the while to to update it with the ubu tool.I have a good 5.0 overclock on it now with 1.375v.I might test it out by weeks end just for kicks unless I hear something here that it's worse than 27 for decent overclocking.We'll see...

Nothing new in Windows 10 build 19569.

With microcode 28 (4790) it seems that i have smoother game-play bfv (time-frames). Has anyone tested it? Also my x-fi titanium sound-card seems to not crackle with bfv when a lot of explosions take place.

Missing items.

cpu906ED_plat22_ver000000CC_2019-12-12_PRD_94F4B441 (<cpu906ED_plat22_ver000000D2_2020-01-09_PRD_02ACFA7D)
cpu906EA_plat22_ver000000CC_2019-12-08_PRD_6DBFEE19 (<cpu906EA_plat22_ver000000D2_2020-01-09_PRD_711B4326)

@westlake Not missing but superceded by D2 on Github.

I have added them to my Intel microcode archive thread.

Zitat von chinobino im Beitrag #399

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@westlake Not missing but superceded by D2 on Github.

I have added them to my Intel microcode archive thread.

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Ah yes it is missing from the latest database, my apologies good sir.

Microsoft today revised the microcode packages for Windows 10 at https://support.microsoft.com/en-us/help...crocode-updates . Nothing new for us there.

!New_cpu50654_platB7_ver02000069_2019-12-20_PRD_6A6A88C5.bin
!New_cpu50656_platBF_ver04002F00_2020-01-14_PRD_C8C9FA74.bin

Nothing new in Windows 10 build 19577.