The inexpensive HP 1400 series don't make an appreciable difference when added in series with my Dell 5324, but I haven't bothered to test to get definitive numbers. Here they sell for circa ~$50 for an 8 port but are unmanaged. Having a couple of managed units like the Dell, unless you're using the added features such as LACP, I'm not seeing much point in them for home use. The Dell does have an independent test done for it that shows it can max out all ports at once, but uses a lot of power doing it (~60W), and has two noisy fans. I paid $60 for the Dell second hand as I wanted it for the SFP ports as I have a ton of them and plenty of fibre interconnects, but never bothered to connect it up as it's quite fast enough as it is.