Hi all,
I have RB2011UiAS-RM for a long time and I upgraded my Internet connection to 1gbit, the internet speed test on the modem is ok (960 mbit/300 mbit), but passing through the board the speed goes down to 240Mbps.
I have two bridges configured 1 for WAN and one for Lan.

I checked all configurations but I think all is ok (but ask me if you need more details).
When I simulate the traffic I see the CPU goes up until 100%
My questions are:
- Can the board reach 1gigabit speed?
- Should I change some settings?
- In case of a negative answer to the first question, which is a good board for home usage? (RB3011UiAS-RM model ?)

Thanks in advance for the help

Each Mikrotik router has official test results published in respective product page. Test results for your device indicate, that real-life routing performance will be around 250Mbps (give or take) ... experience goes that the number best matching Joe Average's reality, is the one under "Routing - 25 ip filter rules - 512 byte packets". And as it happens, that's about what you actually see.
Yes, it's possible to configure devices to allow higher throughput than the one I mentioned ... but considerably better performance is possible only in some particular use cases so don't count on feasibility of any of such recipes.

Nowhere it says that any of MT device can route at wire speed, so the fact your device has 5 gigabit ports doesn't mean it'll rout at that speed. Rather your device is a router/switch combo ... and is capable of wirespeed switching (if configured properly)

When looking for replacement: go for a modern device (which rules out RB3011). There are (more or less) affordable devices which can route at 1Gbps and can be rack-mounted: RB5009 or L009 (barely); these are in the same category as RB2011 and RB3011 were when they were conceived. You can go overboard and get yourself a CCR2xxx, but that's a step higher (both price ticket wise and performance wise).

[edit]: formating

thank you very much for your detailed answer and for explaining me the meaning of the tests, now everything is much clearer

Do you have fasttrack enabled?

wow @onnoossendrijver thanks a lot, I didn't know this feature, with this enable the speed goes up to 760 mbps instead of 230.
I follow https://wiki.mikrotik.com/wiki/Manual:IP/Fasttrack but if you have more settings that I can set please let me know.

There is not much you can do. You may see some small improvements if you remove the WAN bridge (do you really need it?). Or you can gain a tiny bit for improving the firewall rule order..
Like mkx said before: This thing is old! If you have the money, get a RB5009. It's a beast!
RB4011 is also very good, but not much cheaper, and the switch chips suck compared to the switch chip in the RB5009.

Only get an older RB3011/850Gx2/RB450Gx4/... (second hand) if it is really cheap.

I've seen many RB4011/RB5009 for sale on the second hand market in the last year. Some people upgraded, while others probably didn't want to suffer the learning curve. Worth a look...

thanks to all for the answers