I asked @mike.maxwell and @bravenel this exact question and didn’t get an answer.
An ARM architecture upgrade is the only way to get twice the performance for a 500 MHz clock speed increase.
Edit: looks like Arm A53 to A55 + The memory bus is now 32 bit up from 16 bit.
I had a c7 prior to upgrading. The c7 cloud backup that the newer firmware provides, allowed me to backup, shutdown old hub, boot up new hub, join it to my network, restore c7 backup via cloud migration and everything was working properly
Nice. That would make it a fair bit more than just 33%.
Not 200%+ like I'd hoped for, but probably a solid 50-100% better. Really would depend on how RAM speed dependent HE is.
Considering that (from my understanding) apps/drivers are 'put to sleep' where they have their state written out, then 'wake' up where all that state is read back into RAM... having a decent improvement to memory speeds would probably be a fairly significant improvement.
Considering the "boots almost 2x faster" statements, I'm guessing the SOC change is closer to that 100% faster mark than the 50% mark, and definitely a lot better than the 33% from just the CPU speed bump.
Now the only question I have at this point... can a cloud backup (with all my connected ZigBee and Z-wave devices) from a C8-Pro be restored onto a C8?
Being faster alone isn't worth the asking price to me, when I already have a C8 and a C7. But if I can power down my C8 when my C8-Pro arrives, stick the C8 in a drawer, and keep it as a 'cold spare' for if/when the C8-Pro dies, then within a few minutes restore the latest cloud backup from the C8-Pro onto the C8... that would be worth it. More speed, more RAM, and being able to use my C8 as a cold spare so I'm not down for days if there's a hardware failure. That's worth $180 to me.
I've considered buying a second C8 purely for 'cold spare' use. Being able to restore a backup from a C8-Pro onto a C8... that would make getting a C8-Pro a 'no brainer' for me.
I try to have a cold spare of "important devices". I had a cold spare for my C7, then my C8, and now I have one for my C8 Pro.
Just like I have a spare ps/motherboard/cpu/memory for my opnsense box, and SFP modules, cables, and a couple of unifi switches. 
It gets expensive, but has came in very, very handy a few times where I simply didn't want to live with a few days turnaround time to get things working.
Back to your other question - I don't know if you can restore a C8 Pro backup to a regular C8. It's a good question, though! If you can, then I'm mad I didn't think of that... I likely would NOT have purchased a cold spare C8 Pro, as I already have 3x C8s (2x unused now)...
The only thing I have DATA to compare with is on Maker API... I keep stats on my Maker API status/response times.
On my periodic Maker API speed test I watch fairly closely, average response time improved almost exactly 30% from C8 to C8 Pro. 361ms to 255ms.
Same query/devices in query, same hub software version, just different hub. Obviously I'll be watching it over time (only migrated this morning).
You can find your C-8 to C-* Pro answers here:
No, currently the free migration is for upgrades only. So you can migrate from C5/C7 to C8/C8 Pro, or C8 to C8 Pro. For downgrades, you'd need Hub Protect.
I have hub protect. So you’re saying that if I get a C8-Pro to replace my C8, if the C8-Pro broke i could restore a backup onto my old C8? Connected Zigbee and Z-wave included?
I figured we could use a hard benchmark to compare C8 performance against C8 pro. Having an engineering setup with full OS access, I grabbed a copy of the original DaCapo Benchmark Suite. The suite "consists of a set of open source, real world applications with non-trivial memory loads" and takes long enough to run to make a meaningful, if low tech comparison.
Because it's a headless environment, I had to skip a few failing tests from the suite. Here's the full script showing tests that ran and counted towards the final number:
date
java -jar dacapo-9.12-bach.jar avrora > /dev/null 2>&1
java -jar dacapo-9.12-bach.jar fop > /dev/null 2>&1
java -jar dacapo-9.12-bach.jar h2 > /dev/null 2>&1
java -jar dacapo-9.12-bach.jar jython > /dev/null 2>&1
java -jar dacapo-9.12-bach.jar luindex > /dev/null 2>&1
java -jar dacapo-9.12-bach.jar lusearch > /dev/null 2>&1
java -jar dacapo-9.12-bach.jar pmd > /dev/null 2>&1
java -jar dacapo-9.12-bach.jar sunflow > /dev/null 2>&1
java -jar dacapo-9.12-bach.jar tomcat > /dev/null 2>&1
java -jar dacapo-9.12-bach.jar tradebeans > /dev/null 2>&1
java -jar dacapo-9.12-bach.jar tradesoap > /dev/null 2>&1
java -jar dacapo-9.12-bach.jar xalan > /dev/null 2>&1
date
This is the script's output on a C8 pro:
$ ./run_benchmark.sh
Sun Jan 28 19:07:59 UTC 2024
Sun Jan 28 19:15:16 UTC 2024
$ cat /sys/devices/system/cpu/cpufreq/policy0/scaling_max_freq
2016000
Same on the C8:
$ ./run_benchmark.sh
Sun Jan 28 19:08:39 UTC 2024
Sun Jan 28 19:22:41 UTC 2024
$ cat /sys/devices/system/cpu/cpufreq/policy0/scaling_max_freq
1416000
Both hubs run at full speed, with C8 taking 14:02 to complete all benchmarks and C8 pro taking 7:17. That puts C8 pro's time at 51.9% of C8's time. That number is in line with our experience of C8 pro booting in about half the time of the C8.
Hopefully, this comparison helps!
Very nice! We geeks love us some data! Nice to see such a significant performance improvement!
Here is my favorite chart. That extra 1GB of RAM is definitely nice to have available!
Woah! That's a tall cliff to stand on, great view from up there I bet. Looking forward to setting up my C8-Pro tomorrow.
We're all gonna get baseball caps w/"Pro" on it, right?
Just excellent, thanks, Victor!
They have the same radios, so the answer is yes.
The Zigbee radio in the c7 could be backed up, but not restored to. Hence the limitations.
Technically yes, but I can tell you for a fact it can't be done today...
Right now a C8, on any firmware, can't see cloud backups from a C8 Pro at all, and thus can't restore from them.
Likely a UI bug or oversight that may be fixed later, as I agree it "should" be able to. But I never like to assume, thus my statement that I don't know, as I don't... Not for sure anyway.
Thanks. I'll hold off on a C8-Pro until it's possible to restore the backups from one onto a C8. Keeping my current C8 as a cold spare is really the cincher for me to justify the purchase.
If restoring from C8 Pro --> C8 is important, I would wait until it is confirmed it can do it in production firmware.
I really expect it can/will be able to do that and it will be added "soon". But I am a "wait until it is released" kind of guy when it comes to purchase recommendations.
Well, my standard Maker API speed test settled in at 192ms on the Pro, vs 361ms on the C8.
In the end, an almost 50% improvement on this particular test.
Migrate all devices, including the Zigbee devices?!?!?!
It's expected to be able to do that. However, since C8-Pro > C8 is a hub downgrade (free migration is only for hub upgrades), AFAIK you'd need Hub Protect registered on both devices.
C7 > C8 : Yes
C8 > C7 : No, not supported
Download the Hubitat app
