Survey: CPU and VM boot time

While looking through various Qubes forums, I noticed that prospective Qubes users tend to worry about whether their systems are powerful enough. I’ve also wondered what the impact of CPU power on Qubes OS’ operating speed is. There aren’t any good resources on this. Since I don’t have access to a bunch of computers to experiment on myself, I came up with a standardized test we can use to create a handy reference table.

For further details and explanations, please see this thread.

tl;dr - This is a very crude test that just aims to find out the impact of CPU speed on VM start up time, and shouldn’t be impacted by RAM, core count, etc. Hopefully someday there’ll be something like a Qubes compatibility benchmark.


The VM start-up test

  1. Take an up-to-date version of the current release (R4.0). Entering sudo qubes-dom0-update into dom0 should return: No new updates available.

  2. Install a pristine, untouched version of the debian-x-minimal template. The template can be installed by entering sudo qubes-dom0-update qubes-template-debian-10-minimal into dom0. Clone then delete your existing installation if necessary. Please do not modify this template before the test. This includes updating the template.

  3. Shut down all other VMs using qvm-shutdown --all (make sure all your work has been saved).

  4. Run time qvm-start debian-10-minimal and make note of the real time returned. It is recommended you run this test multiple times to get a more reliable result. wrote a little script that’s short enough to manually enter into dom0:

dom0 script


get_real_time() {
  realtime="$(/usr/bin/time -f "%e" qvm-start -q ${qube})"
  qvm-shutdown --wait -q "${qube}"
  echo $realtime 

benchmark() {
  qvm-shutdown --all --wait -q
  for ((i = 0; i < 10 ; i++)); do
    sleep 15
    echo "$(get_real_time)"

  1. Enter your CPU model, VM kernel version, storage type, and VM boot time into the table below (this is a wiki post, so click ‘edit’), rounded to one decimal place and converted to seconds if necessary. If you ran multiple tests, enter the average.



User CPU model VM kernel version VM boot time (s) HDD or SSD?
@fiftyfourthparallel i7-1065G7 5.10.8-1 7.9 SSD
@GWeck i5-7200U 5.4.88-1 8.4 SSD
@fiftyfourthparallel i5-10210U 4.19.147-1 4.8 SSD
@fiftyfourthparallel i5-10210U 5.6.16-1 5.4 SSD
@augsch E3-1231v3 4.9.152-1 8.0 HDD V1605B 5.10.8-1 6.5 SSD i7-3520M 5.4.88-1 8.2 SSD
@johnboy R5 2400G 5.4.98-1 5.2 SSD
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Would adding a column with additional notes make sense? Someone could put in more information if they want like “x220 HDD”.

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What is more important, diskt type (nvme, ssd…), disk encryption or CPU? I have laptop with ssd, hdparm -Tt --direct /dev/sda gives me 435MB/sec 435MB/sec my SSD is full encrypted. If I run the test 3 times, it boots from 7,3s - 8.7s, Kernel is 5.10.3-1, cpu is i7-4810MQ, R4.1

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You’re right–that slipped my mind. I was assuming the computers that interested people were new and therefore came with SSDs. Thanks for pointing that out.

According to some tests @unman did, disk type seems to have the greatest effect. This test was created under the assumption that everyone’s using SSDs.

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I am afraid that the measurements might give a false impression of accuracy. I upgraded the kernel from 5.4.88-1 to 5.10.8-1 and repeated the test, coming to 9.3 s, which at first hinted to a worse performance of the newer kernel. Repeating the test with this new kernel, however, resulted in values between 6.9 s and 11.4 s. If the values differ that much, there must be factors influencing them much more than kernel version or CPU speed, especially as my CPU is supposedly much slower than that of @fiftyfourthparallel.

So to get any meaning out of these tests, it is probably necessary to perform 10 tests or so, and take the average, which is 8,97 s for my configuration (an HP EliteBook 840-G4 with internal SAMSUNG SSD 850, using Kernel 5.10.8-1).


Did you shutdown all other VMs using qvm-shutdown --all? I remember performing multiple tests on R4.1 and the real time returned were all basically identical to one another.

I’m not saying you’re wrong (as I’ve often stressed, I’m not technical), but I feel there might be something else going on, since a Qubes with just Xen and dom0 running shouldn’t have such a large range, with the upper end being more than 50% higher.

I can’t shut down my VMs right now so I’ll try this again later and get back to you with the results.

I shut down all VMs, so there must be something else in the background which I didn’t see. During one of the tests, however, sys-net started again without apparent reason, and I had to shut it down again.

I’ll try again with R4.1, but I think the times wil be longer then, because my R4.1 is running from a USB SSD.

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I checked now with R4.1 and kernel 5.10.13-1 and made sure that no other VM was running. The times are stiil different: 9.2 s, 8.9 s, 12.5 s, 9.3 s and 8.9 s. So most measurements are pretty close, but one is exceptional. It seems that there must be something else running in the background (in dom0 perhaps?).

During my previous tests in R4.0.3, I had the Qube manager running, and as I thought that maybe that was taking time, I had it switched off during my R4.1 tests, but this does not seem to explain the times.

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My R4.1 machine is occupied so I still can’t shut down all VMs (even though the test should be conducted on R4.0). I pulled out an airgapped R4.0 and ran the test using an outdated dom0 and a not-pristine (but close enough) debian-10-minimal.

What I noticed confirmed what I had felt before–my 15nm i5-10210U starts VMs quicker than my 10nm i7-1065G7 (the former has slightly higher clock speeds: 1.6/4.2GHz vs the i7’s 1.3/3.9GHz).

VM start times were closely clustered:

Test # Time (s)
1 5.166
2 4.854
3 4.744
4 4.863
5 4.869
6 4.808
7 4.820
8 4.908

The first one might be anomalous because it was closer to startup.

I still get a scattering of the values, now testing R4.0.3 with all VMs turned off and also the Qube manager turned off. After shutting down the debian-10-minimal template, I also waited some time and checked via the Q widget that this VM was not running any more, and no other VM was running.

Here are my times, with the I5-7200U CPU and the internal disk, using kernel 5.10.13-1:

Test # Time (s)

  1. 7.998
  2. 7.800
  3. 7.995
  4. 7.198
  5. 8.476
  6. 8.475
  7. 5.517
  8. 8.807
  9. 8.012
  10. 8.761

So there is still no clear picture, especially with test 7, which has a much lower value.

My times, CPU E3-1231v3 ,7200RPM HDD, kernel 4.19.152-1:

Test # Time (s)


I have no idea why you’re getting large anomalies. If you include your earlier numbers, your range is between 5.5 and 12.9 seconds, which seems to indicate instability to me (assuming you’ve followed the instructions). But then again, I’m no technician. Have you tried turning your PC on and off again?

I performed the tests on a system that was just started - no actions before the tests.


Dom0 Kernel: 5.10.8-1
CPU: AMD Ryzen Embedded V1605B (4 Cores/ 8 Threads @2.0Ghz with Turbo @3.6Ghz)
Storage: Samsung 970 Evo Plus (M.2 NVMe PCIe 3.0)
RAM: 32 GB DDR4 2400 Mhz


Median: 6.305
Mean: 6.488
Variance: 0.258


I used a little script to obtain the values.



get_real_time() {
  realtime="$(/usr/bin/time -f "%e" qvm-start -q ${qube})"
  qvm-shutdown --wait -q "${qube}"
  echo $realtime 

benchmark() {
  qvm-shutdown --all --wait -q
  for ((i = 0; i < 10 ; i++)); do
    sleep 15
    echo "$(get_real_time)"


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Thanks for sharing the script!

It’s good that it’s short enough to be manually typed into dom0 so we won’t have to ask people to paste things into it. I’ll add this as an option in the instructions.

Edit: I also went ahead and added your results while I was at it

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My more senior “stable” machine:


Dom0 Kernel: 5.4.88-1
CPU: Intel Core i7-3520M (2 Cores/ 4 Threads @2.9Ghz with Boost @3.6Ghz
Storage: Samsung SATA-III SSD
RAM: 8GB DDR3 1600Mhz


Median: 8.245
Mean: 8.163
Variance: 0.934

It turns out my previous test using i5-10210U wasn’t based on a 5.x kernel but a 4.19.147-1 kernel.

I’ve redone the test using a 5.6.16-1 kernel and 's handy dandy script. The results are as follows:

# s
1 5.25
2 5.41
3 6.19
4 5.99
5 4.40
6 4.32
7 5.90
8 6.22
9 6.29
10 4.47

Median: 5.7
Mean: 5.4
Range: 2.0


Manual testing:

# s
1 5.681
2 6.054
3 4.324
4 4.531
5 4.681
6 4.506
7 4.523
8 5.707
9 6.912
10 6.551

Median: 5.2
Mean: 5.3
Range: 2.6

Boot times exhibited a wider variance than using the 4.19 kernel. I also did manual testing (though not in a strictly consistent way) to see if the script affected times significantly. This does not seem to be the case. Based on this I can say that kernel 4.19 loads quicker and with less variance than 5.6.


Qubes 4.1
CPU: AMD A10-5750M


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