A modern hard drive should outperform a gigabit ethernet connection.
My adaptor is an Intel I218-V on the back of an Asus X99S board and it has no issues performing at around 900Mbps or so in iPerf
So I did the same download as yourself and it peaked at 103.6MB/s or 828.8Mb/s so just a bit below the expected speed but close.
Straight after that test Speedtest.net to TNP in Manchester records a lowly 429Mb/s via Chrome browser (VM a similar speed). On the W10 desktop app I am getting even lower. SamKnows is saying 1049 on the last run.
However, I am using a Linksys LRT224 as an intermediary router at the moment which does cause some speed tests to run slower, but ironically still allows the fast steam download.
I do find that speedtest is a bit fickle and not that reliable though and if you can get a fast "real" connection then you can get close to the throughput.
A WD Red which is made to be quiet and runs at 5400rpm and a not been updated since 2013 (AFAIR) can sustain 145MB/s so any modern 7200rpm HDD will be fine some of the larger models now do 200MB/s (WD Red Pro again not new) and possibly newer models 250MB/s due to higher density.
I have no kept up with latest Shingled/Helium tech etc as went all SSD part from my Ext backup Enclosure that is set to Raid10 with 4x WD Reds so that is 190MB/s and slowest part of my PC.
Yeah I figured that my 7200RPM drive should be fast enough but I don't know what to say. Done the test on 5 different games on Steam and it only downloads at max speed when it's writing to my NVME.
Origin/Battle.net are capped at 40 - 45 regardless of the drive I'm downloading to.
is it SATA 1, 2, or 3? that would make a big difference depending on which one it is.
SATA I (revision 1.x) interface, formally known as SATA 1.5Gb/s, is the first generation SATA interface running at 1.5 Gb/s. The bandwidth throughput, which is supported by the interface, is up to 150MB/s.
SATA II (revision 2.x) interface, formally known as SATA 3Gb/s, is a second generation SATA interface running at 3.0 Gb/s. The bandwidth throughput, which is supported by the interface, is up to 300MB/s.
SATA III (revision 3.x) interface, formally known as SATA 6Gb/s, is a third generation SATA interface running at 6.0Gb/s. The bandwidth throughput, which is supported by the interface, is up to 600MB/s. This interface is backwards compatible with SATA 3 Gb/s interface
Speedtest and the like are reporting anywhere from 300 - 650. Might get the odd 750+ here and there.
Samknows is reporting 1090Mbps so it doesn't seem like the router is the issue.
So you are seeing variations in the speedtest.net results from 300 - 750 Mbps. I see similar variations myself.
I doubt that is down solely to the speed of your harddrive. I find that if I've got loads of tabs open on Chrome, other apps open and been working away for hours then the speedtest.net generally shows lower speeds than if I do a clean boot of my PC, allow everything to settle then run speedtest.net.
I also see very different results switching between:
I would say my home system is fairly decent. It's definitely not state of the art but it would be better than 90% of Jo Public's setup. But I don't think all the elements together in my setup allow for a consistent 900Mbps + download speed. On the contrary I think I can reliably get 400Mbps + and often 600Mbps. But the 900Mbps only happens occasionally when all the stars align.
It's certainly not the case that using Cat 6 cable to a 1G NIC will guarantee you 900Mbs+ download. There are a lot of other factors that could limit it.
With the G1 service I really think VM will end up being (even more) swamped by people complaining they're not getting the speeds they're paying for and 99 times out of 100 it will be down to the end-user's setup not the Virgin network. Embedding Samknows was a good move for VM. It's a shame it can run when the Hub4 is in modem mode.
(NB I'm putting the whole 930Mbs vs 1Gbps argument aside as that's being debated in plenty other threads.)