I have recently upgraded my internet to 600mbit up/down and I am only getting a max of ~250mbit through my PC (wired to the router) and on the router itself (using these scripts: https://github.com/richb-hanover/OpenWrtScripts). I have an Archer C7 v2 with the latest version of OpenWrt installed. I can verify it's the router as when I plug in my PC directly to the internet I get the full upload/download speed.
Is there anything in the default configuration that would have to be changed? Thanks
Your device is not fast enough to keep up with those speeds. Look for "fastpath" or "hardware NAT" in this forum for info about possible measures.
At 600mbps your best bet is a mini pc, x86 box and a smart switch. Particularly if you want SQM to keep latency down for VoIP or games.
Beyond that you should probably look at a Wrt32X.
Thanks for pointing me in the right direction. I found some builds with those settings so I'll give them a try tonight. If not, I'll probably go back to stock firmware.
These speeds are just demanding, stock firmware is likely going to underperform as well. Hardware flow offload helps raise the speed for ipv4 mainly, at the expense of typically much worse buffer management (like up to 300ms of bufferbloat is not too hard to achieve depending on how your ISP works). Several major providers are using ipv6, such as all google services, youtube, drive, photos, etc and all facebook services, and many content delivery networks such as Akamai and cloudflare etc. There's no magic bullet that will make old hardware handle 600Mbps routing and have good buffer performance.
You can enable software flow offload in the standard stable build, I'm not sure about hardware offload for your device, though I suspect it's possible in standard build as well.
As a C7 owner, I can vouch for what dlakelan is saying, and with a 300/30 cable connection, I know where the limits are on this hardware. Being the main router and access point, with SQM, it's hard to get past 120mbit. Straight to eth, no wifi, maybe 130-140. W/O SQM, I can see up to 270-290mbit over the wifi, and have seen 350 out of my cable modem on a good day. Have heard of other folks getting 400-450 with faster connections. If you dont care about SQM, (but isnt that one of the reasons you would change from factory?) you could get near full wire speed if you install fasttrack or similar. But, I dont know if routing and nat'ing and running the wifi radios will still run you out of idle time by 600mbits.
I went with a little Zotac CI327 x86 box, and now have the horsepower to SQM a 1Gbit connection and run other stuff... and have my couple of C7's loafing as dumb AP's. Good radio coverage on the C7... Lots of links out there, dlakelan and others have gone this way and he's been mentoring me in getting set up. Cost is similar to a high end router, but you only need to buy it once, you get to reuse a former purchase as a component. You have to be willing to put a few things together. But, then you're future proof for quite a while, with a lot of capacity to do different things.