UPDATE 15 August 2018: Microsoft has released KB updates,for some OS versions, to resolve the CPU utilization issue:
Version
|
OS Build ID
|
Released
|
KB number
|
Windows 10 RS4 (Version 1803)
|
17134.228
|
14 Aug 2018
|
|
Windows 10 RS3 (Version 1709)
|
16299.611
|
14 Aug 2018
|
|
Windows 10 RS2 (Version 1703)
|
|
|
not released yet
|
Windows 10 RS1 (Version 1607)
|
14393.2430
|
14 Aug 2018
|
|
Windows 10 TH2 (Version 1511)
|
N/A
|
N/A
|
N/A
|
Windows 10 TH1 (Version 1507)
|
|
|
not released yet
|
Windows 7 SP1
|
N/A
|
|
|
Windows Embedded 7
|
N/A
|
|
not released yet
|
IMPORTANT! If the temporary workaround for that issue has been implemented by disabling the Spectre Variant 2 mitigation, the mitigation needs to be re-enabled after installing the KB updates: see Microsoft Advisory ADV180002, FAQ 18, "
To enable Spectre Variant 2 mitigations".
For other affected OS versions, the performance issue may be temporarily resolved by disabling the Spectre Variant 2 mitigation. But this only applies to computers with specific AMD processor families and certain builds of the operating system. Use the following procedures to determine if the computer has an affected processor and operating system build:
FIRST: Check the processor family using one of the following options:
Option 1: Use the WMIC command
-
Press the
Windows and
R keys together (Win+R) to open the
Run dialog.
-
Type
wmic then press
Enter.
-
Type
cpu list brief, then press
Enter.
-
Check the family: if it is
Family 21 (21=15h) or
Family 22 (22=16h) the processor is affected.
Option 2: Use Device Manager
-
Press the
Windows and
R keys together (Win+R) to open the
Run dialog.
-
Type
devmgmt.msc then press
Enter to open
Device Manager.
-
Click
View then select
Devices by connection.
-
Locate the AMD processor and double-click to open
Properties window.
-
Click
Details.
-
Select
Device instance path under
Property.
-
Note the FAMILY value. If it is
21 (21=15h family) or
22 (22 = 16h family) the processor is affected.
SECOND: Determine if either the June 2018 or July 2018 cumulative updates are installed:
To determine if the relevant update is installed, identify the version of Windows that is installed on the computer, then check in the tables below to find the KB. Finally, look in windows update history to see if that KB is actually installed.
Use the winver command to determine which Windows version is installed:
-
Press the
Windows and
R keys together (Win+R) to open the
Run dialog.
-
Type
winver then press
Enter to open
About Windows.
-
Note the
Version and
OS Build and compare to Table B.
Table B. Affected OS Build IDs
OS Version
|
Build ID
|
KB Number
|
Windows 10 RS4 (Version 1803)
|
17134.112
|
|
|
17134.137
|
|
|
17134.165
|
|
|
17134.167
|
|
|
17134.191
|
|
Windows 10 RS3 (Version 1709)
|
16299.492
|
|
|
16299.522
|
|
|
16299.547
|
|
|
16299.551
|
|
|
16299.579
|
|
Windows 10 RS2 (Version 1703)
|
15063.1155
|
|
|
15063.1182
|
|
|
15063.1206
|
|
|
15063.1209
|
|
|
15063.1235
|
|
Windows 10 RS1 (Version 1607)
|
14393.2312
|
|
|
14393.2339
|
|
|
14393.2363
|
|
|
14393.2368
|
|
|
14393.2395
|
|
|
14393.2396
|
|
Windows 10 TH2 (Version 1511)
|
N/A
|
N/A
|
Windows 10 TH1 (Version 1507)
|
10240.17889
|
|
|
10240.17194
|
|
|
10240.17918
|
|
Windows 7 SP1
|
N/A
|
|
Windows Embedded 7
|
N/A
|
|
Workaround the issue
If the computer is experiencing performance issues, has one of the affected processors, and the OS Build ID matches one of those in Table A, the performance issues can likely be resolved by following instructions in Microsoft Advisory ADV180002 (see number 18 under FAQs).