I understand that a “future” release of RHEL/Rocky/etc. will no longer support my now-ancient AMD six-core Vishera CPU.
I’m trying to find out which newer CPUs will support the changes causing this incompatibility, but so far I can’t find a suitable search string.
I’d hoped to find a doc here or elsewhere on rockylinux.com that would give me some hints, but so far no such luck.
I’d appreciate hints on what CPU features I need to look for.
Thanks in advance!
Fred
Rocky 9 supports x86_64-v2 and Rocky 10 based on RHEL10 x86_64-v3 so you just need to find out which one it is and if it belongs to one of those groups.
Which is, sadly, a lot easier said than done since there doesn’t seem to be any kind of a database that actually lists that information.
Or if there is, I’d appreciate it if someone could point me to it because I’ve not been able to find it.
On, Rocky 9 for example:
root@rocky9:~# /lib64/ld-linux-x86-64.so.2 --help | grep -i x86-64
Usage: /lib64/ld-linux-x86-64.so.2 [OPTION]... EXECUTABLE-FILE [ARGS-FOR-PROGRAM...]
This program interpreter self-identifies as: /lib64/ld-linux-x86-64.so.2
x86-64-v4
x86-64-v3 (supported, searched)
x86-64-v2 (supported, searched)
so you can see my CPU supports x86-64-v2 and v3, so will be fine for Rocky 10. Check that against yours to find out what it’s got.
The ld-linux-x86-64.so.2 of recent glibc (e.g. like in Rocky 8) has that --help option.
The “microarchitecture levels” are relatively clearly defined sets of CPU instrutions.
See x86-64 - Wikipedia and cpu architecture - How do I check if my CPU supports x86-64-v2? - Unix & Linux Stack Exchange
actually, I’m looking forward to replacing the aging computer, so while the info above is helpful, what I really need to know is how to tell which CPUs on the market implement which features. Might there be a table (and AMD or Intel) listing such info?
I’ll be looking there next.
Thanks again!
Fred
Basically, get a new CPU rather than buying something that has been on the market X amount of years. You can google a lot of information anyway in addition to what @jlehtone linked already. One example of which: What is x86-64-v3? Understanding the x86-64 microarchitecture levels
If you want and need longevity, you buy new hardware to ensure it will run the longest. There are plenty of sites with CPU comparison information which also gives the year they were released. You can find these with google as well.
As I said earlier, though, none of them seem to specifically state whether a given cpu is v2 or v3. Or if there is one, I haven’t managed to find it.
So buying a new CPU comes down to pay-and-pray, and simply hoping that the new one will support v3 or v3.
you nailed it, Frank! the online features lists don’t tell you anything about which instruction extensions they have, you have to pray for divine intervention.
Let’s take a look at my CPU as an example:
11th Gen Intel(R) Core(TM) i5-11400H @ 2.70GHz
from /proc/cpuinfo. Let’s assume I hadn’t even bought my laptop yet, I can then go to say this website: https://www.intel.com/content/www/us/en/products/sku/213805/intel-core-i511400h-processor-12m-cache-up-to-4-50-ghz/specifications.html of which we then take a look at this:
Now we take a look at the wikipedia link that @jlehtone provided, and we can see that due to the AVX-512, we are looking at an x86_64-v4, so will definitely run RHEL10/Rocky10 when x86_64-v3 is the minimum. It’s also easy enough to google that x86_64-v3 started appearing around 2013 or so with AMD having theirs around 2015.
All it takes is looking at the CPU specs and finding out by comparing what instructions are in each architecture. You can find out the date when the CPU was released to ensure you aren’t buying an old one, and the instruction sets will clearly let you find out whether it’s going to be the correct level or not. And for my CPU I found this info within 2 minutes!
Yes they do, see my post above this one.
In addition to Intel and AMD, some third party sites seem to list features too.
For example AMD FX-6300 Specs | TechPowerUp CPU Database
Newer is not always “more” though – earlier Intel consumer CPUs had AVX512.
It’s definitely the long way around the bush to get that information. Check the specs on the manufacturer’s website, see if they list any instruction set extensions, then cross-reference that with a list of extensions on Wikipedia to see if there are any matches between the listed extensions on both websites.
It would be a lot better with less chance of ye-olde-screw-up if Intel and AMD would just say “this CPU is architecture level X” on the spec page. Or provide a list or a table somewhere.
I’m looking at a mini-pc with an AMD Ryzen 7 PRO 5850U Processor. The only page at AMD I’ve found, so far, is this one: https://www.amd.com/en/products/specifications/processors.html which doesn’t seem to give that information. I’ll keep looking.
True it would, but it doesn’t, so… 
Right now we are limited to googling for information, and as shown it’s real easy to do. I know it seems people these days can’t be bothered in googling and prefer to be spoon fed information. Seen plenty of posts on forums where people could have gotten answers to questions far simpler than this one had they actually done a google search. But there we go.
True, the https://www.amd.com/en/support/downloads/drivers.html/processors/ryzen-pro/ryzen-pro-5000-series/amd-ryzen-7-pro-5850u.html has no features.
The AMD Ryzen 7 PRO 5850U Specs | TechPowerUp CPU Database has pulled them up from somewhere.
If you think that is long, then how short and easy is it what MS Windows 11 requires?
The Linux distros at least point to published lists of “we will compile kernel and glibc to have/use/require these CPU instructions”.
Yes, that is whataboutism, so no real excuse. Point is, what distro requires is clear and precise; the ball is on the CPU vendors.
Ah, that’s good. Thanks for the pointer to techpowerup!
Fred
I guess I am going to have to replace my 2012 PC (8 cores @ 4ghz, 32GB) with a compatible tiny PC with a more modern CPU. Good thing there is Debian…