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AidenShaw

macrumors P6
Feb 8, 2003
18,667
4,677
The Peninsula
HT might not even be the best idea if you need to rely on those threads.
One of the first things that I do when I get a new system is to disable hyperthreading - and I've done this since when HT first appeared.

On a case-by-case basis, I may enable hyperthreading. Those cases are when the system spends significant time with all physical cores busy. If you don't have significant periods of time with 100% CPU usage, hyperthreading can hurt your performance. Even if you do hit over 100%, hyperthreading is often only a mild benefit.

On Linux you can dynamically enable/disable logical CPUs by writing to the /sys filesystem.

echo 0 > /sys/devices/system/cpu/cpu113/online​

will instantly remove logical CPU 113 from the system. The command

echo 1 > /sys/devices/system/cpu/cpu113/online​

will put logical CPU 113 back online.

On a typical Linux system the "htop" command will show core usage. For example, it may show:

htop1.jpg

(For some reason, "htop" numbers CPUs from 1 to N, whereas most tools number them from 0 to N-1.)

In this screenshot, CPUs 1 to 72 are the "physical" cores, and CPUs 73 to 144 are the HT "second class" cores. (Core 73 is sharing core 1 resources.) If you iterate the command

echo 0 > /sys/devices/system/cpu/cpu$idx/online​

from $idx=72 to $idx=143 - you'll instantly disable hyperthreading (until the next boot). Write a "1", and instantly the logical core is back.

I've tested quite a few workloads with and without HT using this technique - and HT is seldom a big win.

Also note that different systems enumerate cores differently. I think that Windows puts logical core 0 and logical core 1 on the same physical core (and logical core 142 and logical core 143 on the same physical core).
 
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Demigod Mac

macrumors 6502a
Apr 25, 2008
840
288
Don't forget you actually have to get hit with a payload for the vulnerability to matter. For that to happen you have to be exposed to malicious code, like being tricked into opening a trojan or visiting a website with an attack script. This isn't a new, innovative way for malicious code to be delivered to a machine, just a new thing malicious code can do once it's been downloaded and executed. Reading news reports on these vulnerabilities makes it sound like a hacker just needs to sneeze at your machine to break in, which isn't necessarily true.
  • Is your web browser up to date?
  • Do you have an adblocker extension installed? (to prevent malvertising attacks)
  • Xprotect definitions up to date?
  • Is your Mac behind a router with a firewall?
  • Do you avoid visiting shady websites?
  • Do you carefully vet the source of the software you download?
You'll probably be fine, then. Install NoScript if you're still paranoid. Internet street-smarts should be your front-line defense. If you get hit with an attack but have HT disabled, guess what - you still have a problem because malicious code is still running on your machine.
 

Mac_User 0101

macrumors regular
Oct 8, 2017
133
43
One of the first things that I do when I get a new system is to disable hyperthreading - and I've done this since when HT first appeared.

On a case-by-case basis, I may enable hyperthreading. Those cases are when the system spends significant time with all physical cores busy. If you don't have significant periods of time with 100% CPU usage, hyperthreading can hurt your performance. Even if you do hit over 100%, hyperthreading is often only a mild benefit.
That is really interesting and you have me looking at this different now. A lot of my software and particularly plugins utilize distributed processing across multiple cores. I'll have to try disabling HT while running a large session with a lot of plugins and see if it's the same CPU performance if not better.
[doublepost=1558142342][/doublepost]
  • Is your web browser up to date?
  • Do you have an adblocker extension installed? (to prevent malvertising attacks)
  • Xprotect definitions up to date?
  • Is your Mac behind a router with a firewall?
  • Do you avoid visiting shady websites?
  • Do you carefully vet the source of the software you download?
You'll probably be fine, then. Install NoScript if you're still paranoid. Internet street-smarts should be your front-line defense. If you get hit with an attack but have HT disabled, guess what - you still have a problem because malicious code is still running on your machine.
Actually, what worried me most was the vulnerability was demonstrated attacking a computer running the current version of TOR browser within a VM instance of Tails. Just goes to show with the right set of skills a hacker will achieve their payload regardless of most basic security implementations. I guess these Intel processors are just RIDL'd with security holes:p
 

Demigod Mac

macrumors 6502a
Apr 25, 2008
840
288
Actually, what worried me most was the vulnerability was demonstrated attacking a computer running the current version of TOR browser within a VM instance of Tails. Just goes to show with the right set of skills a hacker will achieve their payload regardless of most basic security implementations. I guess these Intel processors are just RIDL'd with security holes:p

I think that was a bit of dramatic flair on the researchers' part. If something as low level as the CPU is compromised then it doesn't matter if the target is Notepad.exe or a TOR browser running in a VM. But once again, in order to pull off that neat trick the attacker needs to successfully circumnavigate multiple layers of security and hit your machine with a payload that exploits the vulnerability, not to mention consider you a worthwhile target for all the effort. Entities that should be worried about this would include governments, large corporations and data centers - the most likely targets for a sophisticated information espionage attack.

To conclude, disabling hyperthreading on a Mac used in a home or small business seems really unnecessary if you follow basic internet security practices.
 

cheezegrate

macrumors newbie
May 15, 2019
18
4
Those cases are when the system spends significant time with all physical cores busy. If you don't have significant periods of time with 100% CPU usage, hyperthreading can hurt your performance.
That's what I was trying to get at. But as always: YMMV
(For some reason, "htop" numbers CPUs from 1 to N, whereas most tools number them from 0 to N-1.)
You can change that in the settings.

Are we getting too off-topic here...?

Cheers
 

yager

macrumors newbie
May 18, 2019
1
1
Could be wrong, but I cannot see Intel staying the course and refusing to update the microcodes for the X56 proc regardless what they put in print. Why, this was one of the main procs in the HP 360/380 line for the 5520 chipset in the G7s. There are a lot of G7s out there in data centers all over the world still running and still under extended warranty by HP. Yes, you would be surprised. Unless Intel is willing to assist HP and not Apple. There would be too much blowback coming out of this vulnerability and Intel sitting on their hands. Maybe Intel seen Apple had so much fun on their planned obsolescence class action suite, Intel wanted to get in some of that action too.
 

tsialex

Contributor
Original poster
Jun 13, 2016
13,455
13,602
Could be wrong, but I cannot see Intel staying the course and refusing to update the microcodes for the X56 proc regardless what they put in print. Why, this was one of the main procs in the HP 360/380 line for the 5520 chipset in the G7s. There are a lot of G7s out there in data centers all over the world still running and still under extended warranty by HP. Yes, you would be surprised. Unless Intel is willing to assist HP and not Apple. There would be too much blowback coming out of this vulnerability and Intel sitting on their hands. Maybe Intel seen Apple had so much fun on their planned obsolescence class action suite, Intel wanted to get in some of that action too.
I hope that I'm wrong, but I'm inclined to think that Intel announced that they don't plan to issue microcode corrections for Nehalem and Westmere Xeons to force enterprise upgrades for servers with these processors still in use.

Intel will get a lot of enterprise blowback and probably some from angry workstation users, that they effectively don't care, but a lot of CTOs will think that's the time of upgrading anything Nehalem/Westmere anyway and thats the push they need to justify spending the money.

The financial gains will be more than the blowback and thats what Intel wants. They care zilt for Mac Pro users.

Now let's go back to the usual BootROM topics.
 

flehman

macrumors 6502
Feb 21, 2015
352
194
In case this info is helpful to anyone. I am on a 4,1->5,1 with a MVC-flashed GTX 980 and still on HS 10.13.6 due to lack of drivers for Mojave. I was still able to download the Mojave full installer and run the 144 BootROM upgrade. I guess the installer doesn’t check the GPU too closely during the BootROM upgrade.
 

h9826790

macrumors P6
Apr 3, 2014
16,656
8,587
Hong Kong
In case this info is helpful to anyone. I am on a 4,1->5,1 with a MVC-flashed GTX 980 and still on HS 10.13.6 due to lack of drivers for Mojave. I was still able to download the Mojave full installer and run the 144 BootROM upgrade. I guess the installer doesn’t check the GPU too closely during the BootROM upgrade.

It checked your GPU. 980 is a Metal supported GPU. You can check your system info.

In HS, when web driver is loaded, Metal is available. That’s why Mojave installer can trigger the firmware update.

If you make a Mojave USB installer (or even simply disable web driver in HS), and use the Mac EFI UGA Display ability to run the installer. There will be no Metal support GPU detected, and the firmware update won’t be triggered.

It’s a matter of if web driver / Metal available in your current OS, not Mojave.
 
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flowrider

macrumors 604
Nov 23, 2012
7,323
3,003
In case this info is helpful to anyone. I am on a 4,1->5,1 with a MVC-flashed GTX 980 and still on HS 10.13.6 due to lack of drivers for Mojave. I was still able to download the Mojave full installer and run the 144 BootROM upgrade. I guess the installer doesn’t check the GPU too closely during the BootROM upgrade.

Thanks for your post, but it's posted in the wrong thread. Many of use have done what you describe, it's detailed in this thread:

https://forums.macrumors.com/thread...-mojave-bootrom-upgrade-instructions.2142418/

Personally I am running an MVC flashed GTX 1080 in 10.13.6 (17G7024).

Lou
 
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macsforme

macrumors regular
Mar 16, 2007
146
88
FWIW, with the 144 firmware and the NVRAM settings to disable HyperThreading, my Windows 10 UEFI installation (yes I know, I know) is unstable. It intermittently freezes on the Windows logo at the beginning of the boot sequence, before the spinning wheel, and goes no further. When it does boot successfully, it shows HyperThreading disabled, as others have pointed out. If I reset the NVRAM to clear out those settings, Windows goes back to being stable again.

I’m not sure if reinstalling Windows with those NVRAM settings in effect would help, but I just reinstalled Windows for other reasons so I’m not super keen on doing that. I’m also afraid to mess with it too much more, since I think it’s freezing right around when the SecureBoot/certificate stuff happens, and I know that is already a known problem area for these machines...
 

trifero

macrumors 68030
May 21, 2009
2,958
2,801
FWIW, with the 144 firmware and the NVRAM settings to disable HyperThreading, my Windows 10 UEFI installation (yes I know, I know) is unstable. It intermittently freezes on the Windows logo at the beginning of the boot sequence, before the spinning wheel, and goes no further. When it does boot successfully, it shows HyperThreading disabled, as others have pointed out. If I reset the NVRAM to clear out those settings, Windows goes back to being stable again.

I’m not sure if reinstalling Windows with those NVRAM settings in effect would help, but I just reinstalled Windows for other reasons so I’m not super keen on doing that. I’m also afraid to mess with it too much more, since I think it’s freezing right around when the SecureBoot/certificate stuff happens, and I know that is already a known problem area for these machines...
Good to know. Thnx.
 

mrtang42

macrumors member
Apr 19, 2019
73
18
FWIW, with the 144 firmware and the NVRAM settings to disable HyperThreading, my Windows 10 UEFI installation (yes I know, I know) is unstable. It intermittently freezes on the Windows logo at the beginning of the boot sequence, before the spinning wheel, and goes no further. When it does boot successfully, it shows HyperThreading disabled, as others have pointed out. If I reset the NVRAM to clear out those settings, Windows goes back to being stable again.

I’m not sure if reinstalling Windows with those NVRAM settings in effect would help, but I just reinstalled Windows for other reasons so I’m not super keen on doing that. I’m also afraid to mess with it too much more, since I think it’s freezing right around when the SecureBoot/certificate stuff happens, and I know that is already a known problem area for these machines...

FYI, my legacy mode win 10 1809 runs flawless after I disabled the HT.
 

bookemdano

macrumors 68000
Jul 29, 2011
1,514
846
Not for me right now as I'm doing a bunch of Handbrake encoding. Perhaps I will when I'm done with that project.
 

Norbert Mikołajczyk

macrumors 6502
May 26, 2016
346
171
intel give me a discount on new Mac Pro or just do what you need to do and patch the cpus!!!
I'm so angry at them that I really can't imagine to buy new pricey Mac Pro with cpus from them.
I would rather switch to amd.
My current beefed Mac Pro is doing just fine and the new AMD VII GPU will expand its possibilities even more with hardware H265 support.
 
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tsialex

Contributor
Original poster
Jun 13, 2016
13,455
13,602
Today @orph sent his mid-2010 dump to check, his Mac Pro can't boot W10 anymore. His NVRAM is a mess and I had to improve my signature file to just to parse the dump.:eek:
  • Multi MemoryConfigs, 25 entries.
  • 12 PanicInfoLogs (Kernel Panics) with a different format than what I usually found in previous dumps
  • 2 IASInstallPhaseList logs,
  • 3 IASCurrentInstallPhaseBoot logs.
Screen Shot 2019-05-20 at 14.22.23.png


Signature version 8:
  • corrects the start of 1st and 2nd NVRAM stream,
  • implements logic checks to detect and show 11 and 12-digits SSN,
  • implements logic checks to detect and show 3 and 4 digits HWC,
  • correctly detects the second format for Kernel Panics, calling it B for now.
Some more improvements and I can release it publicly or send a patch for binwalk, still have to decide what's best.
 

tsialex

Contributor
Original poster
Jun 13, 2016
13,455
13,602
Today Apple re-issued:
  • 10.14.5 combo/delta,
  • Security Update 2019-003 for 10.12.6,
  • Security Update 2019-003 for 10.13.6
  • iTunes Device Support
All of last week non-beta releases were deprecated. Reissues have the same builds as last week:
  • 18F132 build for 10.14.5
  • 17G7024 for Security Update 2019-003 for 10.13.6
  • 16G2016 for Security Update 2019-003 for 10.12.6
Screen Shot 2019-05-20 at 22.19.23.png

[doublepost=1558403757][/doublepost]No firmware changes, btw.
 
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TheStork

macrumors 6502
Dec 28, 2008
296
190
Today Apple re-issued:
  • 10.14.5 combo/delta,
  • Security Update 2019-003 for 10.12.6,
  • Security Update 2019-003 for 10.13.6
  • iTunes Device Support
All of last week non-beta releases were deprecated. Reissues have the same builds as last week:
  • 18F132 build for 10.14.5
  • 17G7024 for Security Update 2019-003 for 10.13.6
  • 16G2016 for Security Update 2019-003 for 10.12.6
View attachment 838170
[doublepost=1558403757][/doublepost]No firmware changes, btw.
Does this mean we should manually download the updated updates and re-install them? Are the build numbers different on the newer updates?
 
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