Apple's macOS is optimised for flash storage, or SSD storage. iMacs with traditional, mechanical hard drives don't perform well with the newer operating systems.
Adding RAM and replacing the old-style hard drive with a solid-state drive will increase the performance so much that it will perform better than ever before - even when it was new.
500GB Solid State Drive - £80 + vat
1TB Solid State Drive - £125 + vat
Different models require different RAM, so call 020 3393 5098 for a model-specific quote.
Labour Prices: We can fit the SSD and install any macOS of your choice including the latest macOS so that, on return to you, it's as if new and 'out-of-the-box'. Alternatively, we can fit the SSD, and then migrate your existing data and apps back to the new SSD so that, on return to you, it would be identical to when you brought it in to us, only much, much faster.