Replace *all* of your HDDs with this massive 8TB Samsung 870 Qvo SSD
Samsung's 870 Qvo SSD is one of the best options for high-capacity solid state storage, with a simple 2.5-inch form factor that doesn't take up a valuable M.2 or PCIe slot and a fast-enough SATA connection. While performance is good, at up to 550MB/s for reads and a little less for writes, the real benefit here is having up to 8TB of silent, reliable and low latency storage.
You can currently pick up this RPS-recommended gaming SSD in its ultimate 8TB form for less than £415 from two places in the UK: Tech Next Day, where you can use code TND-10 to get it for £414, and Amazon, where you can get the drive for £412. I've included both options in case you have a preference, and in the event the drive goes out of stock at this reduced price by the time you come to click the links below!