Number of cores and other CPU characteristics
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Vít Šesták
Feb 2, 2017, 4:50:49 AM2/2/17
to qubes-users
Choosing the right CPU is about choosing the right tradeoff. The tradeoff is not only between price, power consumption and performance. We can also balance single-core performance to multi-core performance, or we might want some enhancements for some specific tasks, like AES-NI. And many more.
I'd like to ask how should Qubes affect my choice (looking at Qubes 4 and newer):
* Obviously, it needs to meet the requirements mentioned at https://www.qubes-os.org/doc/system-requirements/ .
* I might want TXT for AEM (this is not performance-related, though).
* Qubes has GPU for all VMs emulated on CPU. (I believe the GPU emulation runs in the VM itself or in its stubdom.) This might increase need for multiple cores. (Unsure how much.) This might become more important when considering hiDPI or other GPU-intensive tasks.
* Qubes will typically use encryption (at least for data storage), which makes AES-NI potentially useful. It might also utilize an extra core.
* Qubes typically runs multiple VMs at once. I believe this introduces just a minor CPU overhead – while you have more OSes running at once, one VM will have fewer processes. Typically, IMHO at most one VM is performing CPU-bound tasks.
There are my more specific questions:
1. Does Qubes affected desicion between dual-core and quad-core CPUs? While Qubes will more likely utilize multiple cores, I believe that dual-core should be enough in most cases.
2. Is there anything wrong with Intel's U-series? One of considered CPUs is Intel i7 7500U, which seems to provide excellent single-core performance with low power consumption.
3. Should I be picky about integrated graphics? Since it is used in dom0 only, I don't think its performance is important in QubesOS. Maybe it will become important when XenGT is integrated in QubesOS (which is not sure if it happens at all).
4. Is there anything else I should be aware of when looking at recent i7 (or maybe i5) CPUs?
Regards,
Vít Šesták 'v6ak'
I'd like to ask how should Qubes affect my choice (looking at Qubes 4 and newer):
* Obviously, it needs to meet the requirements mentioned at https://www.qubes-os.org/doc/system-requirements/ .
* I might want TXT for AEM (this is not performance-related, though).
* Qubes has GPU for all VMs emulated on CPU. (I believe the GPU emulation runs in the VM itself or in its stubdom.) This might increase need for multiple cores. (Unsure how much.) This might become more important when considering hiDPI or other GPU-intensive tasks.
* Qubes will typically use encryption (at least for data storage), which makes AES-NI potentially useful. It might also utilize an extra core.
* Qubes typically runs multiple VMs at once. I believe this introduces just a minor CPU overhead – while you have more OSes running at once, one VM will have fewer processes. Typically, IMHO at most one VM is performing CPU-bound tasks.
There are my more specific questions:
1. Does Qubes affected desicion between dual-core and quad-core CPUs? While Qubes will more likely utilize multiple cores, I believe that dual-core should be enough in most cases.
2. Is there anything wrong with Intel's U-series? One of considered CPUs is Intel i7 7500U, which seems to provide excellent single-core performance with low power consumption.
3. Should I be picky about integrated graphics? Since it is used in dom0 only, I don't think its performance is important in QubesOS. Maybe it will become important when XenGT is integrated in QubesOS (which is not sure if it happens at all).
4. Is there anything else I should be aware of when looking at recent i7 (or maybe i5) CPUs?
Regards,
Vít Šesták 'v6ak'
Chris Laprise
Feb 2, 2017, 6:32:37 PM2/2/17
to Vít Šesták, qubes-users
On 02/02/2017 04:50 AM, Vít Šesták wrote:
> Choosing the right CPU is about choosing the right tradeoff. The tradeoff is not only between price, power consumption and performance. We can also balance single-core performance to multi-core performance, or we might want some enhancements for some specific tasks, like AES-NI. And many more.
I'd say its the details that the PC vendor execute on the motherboard
> Choosing the right CPU is about choosing the right tradeoff. The tradeoff is not only between price, power consumption and performance. We can also balance single-core performance to multi-core performance, or we might want some enhancements for some specific tasks, like AES-NI. And many more.
that matter more than anything. The specific way chipsets are wired, the
way the BIOS initializes certain features, peripheral chips that might
not be FOSS-friendly, etc. Plus, the number of USB controllers and the
way the keyboard is wired (PS2 vs USB). These things make or break
compatibility with secure Qubes configurations.
So, until we have a running pre-release of R4, we won't really know
which models work.
As for the CPU itself, AES-NI seems like the must-have to me. IIRC it
can prevent side-channel attacks whereas software AES cannot. Luckily,
its a common option on x86 processors aimed at PCs. Of course, I'll also
recommend TXT and TPM if it makes Anti Evil Maid work.
RAM is also a security issue because of attacks like rowhammer. Some
people recommend an ECC-capable CPU or chipset to help mitigate them.
4. Is there anything else I should be aware of when looking at recent i7 (or maybe i5) CPUs?
Chris
Vít Šesták
Feb 3, 2017, 1:45:30 AM2/3/17
to qubes-users
Sure, we can't say definitely anything about conpatibility with Qubes 4. Maybe I'll buy the laptop after the release of at least Qubes 4 RC1. Now, we can estimate. Performance requirements are hopefully estimatable now.
Multiple USB controllers: I am aware of this (must have for me, because I have external Ergo Ergodox keyboard), but this has already been mentioned in requirements.
On AES-NI: I agree.
ECC RAM: Good point. Unfortunately, those laptops I found with ECC are very very expensive, say $2000 (plus VAT) or more. 😔
Regards,
Vít Šesták 'v6ak'
Multiple USB controllers: I am aware of this (must have for me, because I have external Ergo Ergodox keyboard), but this has already been mentioned in requirements.
On AES-NI: I agree.
ECC RAM: Good point. Unfortunately, those laptops I found with ECC are very very expensive, say $2000 (plus VAT) or more. 😔
Regards,
Vít Šesták 'v6ak'
WillyPillow
Feb 4, 2017, 7:16:40 PM2/4/17
to Vít Šesták, qubes-users
-------- Original Message --------Subject: [qubes-users] Number of cores and other CPU characteristicsLocal Time: February 2, 2017 9:50 AMUTC Time: February 2, 2017 9:50 AMTo: qubes-users <qubes...@googlegroups.com>Choosing the right CPU is about choosing the right tradeoff. The tradeoff is not only between price, power consumption and performance. We can also balance single-core performance to multi-core performance, or we might want some enhancements for some specific tasks, like AES-NI. And many more.I'd like to ask how should Qubes affect my choice (looking at Qubes 4 and newer):* Obviously, it needs to meet the requirements mentioned at https://www.qubes-os.org/doc/system-requirements/ .* I might want TXT for AEM (this is not performance-related, though).* Qubes has GPU for all VMs emulated on CPU. (I believe the GPU emulation runs in the VM itself or in its stubdom.) This might increase need for multiple cores. (Unsure how much.) This might become more important when considering hiDPI or other GPU-intensive tasks.* Qubes will typically use encryption (at least for data storage), which makes AES-NI potentially useful. It might also utilize an extra core.* Qubes typically runs multiple VMs at once. I believe this introduces just a minor CPU overhead – while you have more OSes running at once, one VM will have fewer processes. Typically, IMHO at most one VM is performing CPU-bound tasks.There are my more specific questions:1. Does Qubes affected desicion between dual-core and quad-core CPUs? While Qubes will more likely utilize multiple cores, I believe that dual-core should be enough in most cases.2. Is there anything wrong with Intel's U-series? One of considered CPUs is Intel i7 7500U, which seems to provide excellent single-core performance with low power consumption.
AFAIK, [this attack](http://blog.ptsecurity.com/2017/01/intel-debugger-interface-open-to.html) only work on the U-series.
3. Should I be picky about integrated graphics? Since it is used in dom0 only, I don't think its performance is important in QubesOS. Maybe it will become important when XenGT is integrated in QubesOS (which is not sure if it happens at all).4. Is there anything else I should be aware of when looking at recent i7 (or maybe i5) CPUs?Regards,Vít Šesták 'v6ak'
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