I am trying to establish whether the hEX RB750Gr3 router would be a bottleneck with a 1Gbs Internet feed. To that end, I am reviewing the performance results stated at the following link

https://mikrotik.com/product/RB750Gr3#f ... ifications

The test results here are broken out based on frame sizes of 1518, 512 and 64 bytes.

My question is what determines the frame size that is used for any given transmission?

For example, when I look as stats for my WAN Ethernet port, it seems there is traffic for all three frame sizes:

Tx/Rx 256-511 20150285/54322579
Tx/Rx 512-1023 39590895/80003728
Tx/Rx 1024-1518 96997023/638942374

How should I interpret this in terms of evaluating the max throughput to expect from a 1Gbps Internet feed when using the RB750Gr3? Thank you for any assistance.

Of course there will be different sizes, since you will be forwarding all kinds of different traffic at the same time. This is why such tests are just used for comparing one device to another. They will not tell you the actual throughput you will get, since the real life situation can't be predicted.

Let me ask the question differently. When using this router with a 1Gbps Internet link, to what extent is it likely to be a bottleneck for typical Web browsing and media streaming scenarios?

Alternatively, what results should be expected when conducting a speed test using speedtest.net with this router and a 1Gbps link? (Assume out of the box configuration.)

~15% cpu with ~250mbps upload, 30.000pps
No firewall, active fast track.

~15% cpu with ~250mbps upload, 30.000pps
No firewall, active fast track.

It should be able to do a lot better, assuming you test with multiple streams.

~15% cpu with ~250mbps upload, 30.000pps
No firewall, active fast track.

Seems consistent with what I've saw: about 6% CPU usage, with 95Mbps (IPv4). Using fasttrack, NAT, PPPoE and some firewall rules. No queues, no VLAN.

To clarify the above. If CPU is only at 15%, it means it will do much better, since there is plenty of resources available still

Correct, it's a iptv flux so it is pretty steady. Connection is pppoe with 1Gbps/500mbps. Can't test the full speed, no pc is connected to this router.

1gbps should be no problem for this router, I measured about 30% CPU on 1gbps download with fasttrack enabled, though obviously it depends on the complexity of your firewall and other configuration.