For reasons not pertinent to PIs, I started researching wifi performance, and would like the assembled multitudes to comment on the correctness, or otherwise of what I have found.
- All Pis with built-in Wifi use the Broadcomm chip
- This chip is not capable of 5Ghz connectivity
- Nor is it capable of 40Mhz dual channel operation
- ergo it *cannot* connect at *more* than 72Mbps
And its often _way_ worse than that.
Both my Pi3B+ connect to my 5Ghz wifi.
+++!
can you show what chipsets/drivers and what protocols they are using?
It would be nice to tabulate the results
The Pi 3B+ and 4B have 5 GHz WiFi. I think the chips support 40MHz on
2.4GHz, but the driver doesn't.All my 3B+s and 4Bs have Ethernet, so I can't check on the 5GHz performance, but the 3Bs and Zeros scattered around the house do about
20-30Mbps up and down, as do the 2Bs with USB WiFi adaptors.Just failed over a 4B on to 5GHz WiFi, its fairly close to the router but only gives 88.6Mbs down, and 75.3 Mbs up.
So I recommend if you need speed, use Ethernet. Up to the 3B you should get 96/92Mbps, the 3B+ does 327/270Mbs, and the 937/832MBps down/up.
---druck
lshw shows:
*-network description: Wireless interface physical id: 2 logical name: wlan0 serial: b8:27:eb:fb:cc:a1 capabilities: ethernet physical wireless configuration: broadcast=yes driver=brcmfmac driverversion=7.45.206 firmware=01-88ee44ea ip=192.168.23.152 multicast=yes wireless=IEEE 802.11iwconfig: wlan0 IEEE 802.11 ESSID:"CHRISPLACE-A" Mode:Managed Frequency:5.3 GHz Access Point: 80:3F:5D:FA:4D:FA Bit Rate=78 Mb/s Tx-Power=31 dBm Retry short limit:7 RTS thr:off Fragment thr:off Encryption key:off Power Management:on Link Quality=70/70 Signal level=-31 dBm Rx invalid nwid:0 Rx invalid crypt:0 Rx invalid frag:0 Tx excessive retries:0 Invalid misc:0 Missed beacon:0
# cat /sys/class/net/wlan0/device/vendor
0x02d0 # cat /sys/class/net/wlan0/device/device 0xa9a602d0 is Broadcom
The 3B+ and 4 have 5 GHz capable wifi, apparently using the Cypress CYW43455 says
3b+ 4b & pi400 all speak 5ghz
not sure about max speed
It is indeed a Cyprus chip and yes it does support BT 5.0 as per datasheet linked here..
Cypress bought the Wi-Fi assets from Broadcom, hence it's now a Cypress part that was designed by Broadcom, using Broadcom's vendor ID.
Theo
Op 21-01-2021 om 16:24 schreef The Natural Philosopher:
See also
Op 25-01-2021 om 09:12 schreef A. Dumas:
Oh wow, from one of the first posts there: "So link bumped to 433 from
200 [Mb/s]". That looks promising.Op 25-01-2021 om 09:16 schreef A. Dumas:
D'oh! From a bit further: "The WiFi chip is connected via a 4-bit SDIO link that typically runs at 41.7MHz giving an upper limit on throughput of ~160Mbs."
So the link going to 433 Mb/s won't make a difference, except in this sense: "being able to properly use the wide channels means that the channel (which is a shared medium) is occupied for a shorter time, leaving more time for other devices."
Op 25-01-2021 om 09:27 schreef A. Dumas:
Tiny bit more detail in a different thread for the xxx56 version (which is in the Pi400):
"In terms of improving your throughput further you are probably limited by the SDIO interface. "sudo cat /sys/kernel/debug/mmc1/ios" shows the state of that link. The bus clock has to be an even integer divisor of the emmc clock, which is currently fixed at 250MHz, hence the 41.67MHz. Tweaking the EMMC clock ought to make 50MHz attainable, but for clock synchronisation reasons that would also require changing the core clock. Although not trivial, I think there are potential gains to be made here."
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