I guess that 4450 requests/s to one IP, or even spread across multiple IPs, could trigger some alarms if the victim is alert. Unfortunately, I'm not that familiar with IDS/IPS's to answer that with much confidence.
In any case, an attacker has a lot of options. The requests do not need to be made sequentially, so an attacker could basically start and resume his attack whenever he wants, e.g. when the victim is away from keyboard (which he can estimate based on the network traffic someone usually generates). An attacker could also simply slow down the number of requests/s, although this results in a larger number of hours required for a successful attack.
As for energy/CPU consumption, I don't think that'd be a big concern. When the practical attack was performed, the CPU usage went up to around 75%, still allowing one to visit other websites without noticing anything. So unless one would closely monitor the CPU/network usage, I don't think the average victim would notice it.
It's not a line of defense. I'm thinking about less computer literate people. Do you know a friend or family member that would call you and say "My laptop's really hot, loud, and slow, but it's not doing anything!" and ask for advice?
I guess that 4450 requests/s to one IP, or even spread across multiple IPs, could trigger some alarms if the victim is alert. Unfortunately, I'm not that familiar with IDS/IPS's to answer that with much confidence.
In any case, an attacker has a lot of options. The requests do not need to be made sequentially, so an attacker could basically start and resume his attack whenever he wants, e.g. when the victim is away from keyboard (which he can estimate based on the network traffic someone usually generates). An attacker could also simply slow down the number of requests/s, although this results in a larger number of hours required for a successful attack.
As for energy/CPU consumption, I don't think that'd be a big concern. When the practical attack was performed, the CPU usage went up to around 75%, still allowing one to visit other websites without noticing anything. So unless one would closely monitor the CPU/network usage, I don't think the average victim would notice it.