I've just put a 256GB SSD in place of the optical drive in my 2009 iMac. I'm impressed at how much better it performs and feels, it boots far quicker and there's noticeably less lag when opening apps and files. Copying large files is significantly faster. However I just ran a speed test with BlackMagic and am somewhat disappointed with the test results (see attachment.) My stock 1TB internal HD gets read and write scores of about 100MB/s so the read and write of the SSD drive (especially read) are significantly quicker, so the upgrade certainly wasn't a waste of time. But they're nowhere near the 300MB/s+ the SSD is supposed to achieve. So I was just wondering if this is to be expected. I realise that the optical drive connection is only SATA II, could this be to blame? Are manufacturer read/write speeds always so optimistic, or is the drive possibly faulty? I'd be interested to know if anyone that's done the same upgrade could share their test results. Thanks.