I've been trying to improve my Logos performance, and done quite well so far. A new graphics card, and some very profitable overclocking has given me the following Windows Experience Index:

So you can see I'd really like to improve disk performance. The problem is that the drive I have at the moment is a 7,200rpm Seagate Barracuda, albeit a 10th generation model. I don't think that's a bad drive, and I don't know how to improve on it. I'm not averse to getting a smallish disk that I just keep for applications that need high speed, but I'm not sure I can afford SSD, and anyway I'm concerned that the random read/writes that Logos does most often wouldn't get best value out of a drive like that.
So, the question is: can anyone recommend a really quick drive that isn't too expensive (<$100 ideally). I know there's other factors at play, but if you have a primary hard disk of with a Windows performance index of 6.5+ or above, I'd be very interested.