2019 iMac configuration advice

Dunno if you've already made your purchase...and I know you have already said a few times that you can't afford bumping up to the 1TB SSD...but I was able to test Photoshop files on the latest model iMac (4.2GHz quad-core 7th-generation Intel Core i7, 64GB 2400MHz DDR4, Radeon Pro 580) using the 512, 1TB and 2TD SSD's and I can safely state that the bigger the drive, the happier you're gonna be, especially if you're working on BIG files.

I tested all three configs using GB+ sized TIFFs and the results were eye-opening. With a 3GB TIFF, the 1TB SSD was almost twice as fast as the 512 on tasks like Content Aware Fill, most Transform functions (rotate, warp, perspective) and filters like Blur, Render and Stylize. Moving to the 2TB SSD showed another speed increase of around 20-25%.

I never bothered testing if these speed increases were consistent using smaller, sub-GB sized files, since 95% of my workflow involves huge, layered 16bit TIFFs processed from LEAF RAW files, but having that extra onboard scratch disc space certainly convinced me to buy the biggest SSD available, even though it's stupidly priced.

Thank you all for your input. I feel validated in my choices. Would love to have a bigger SSD drive and even more RAM, but won’t be able to afford it this time around. Really appreciate your time and advice.

Your planned system should do fine with the RAM you selected.  Personally, I would beef up the RAM more, to future proof things a bit. Then again,  my MacBook Pro have been running with 8Gigs of RAM for over the past 5 years and its still runs Photoshop with no issue

You aren't going to have any performance problems and you don't need a NAS. Stick with your planned system.

Hi lesnicole,
the configuration you selected for your iMac is perfect for your purposes. But my advice is to keep your working files and the OS on your main drive (the 500gb SSD in this case). But I know in many cases this will not be sufficient but, as D Fosse said before, in cases like yours there are 2 main factors who will affect your PS performances, ram and scratch disk. But lets say you are going to open a PSD file on an external drive the main part of the job will be still done on your RAM and SSD (if you have enough resources) and just when you will save your file you will face some slowness. Of course the best choice, as said before, is having your working file on your local SSD. In this case you can consider starting with the smallest SSD available on the Apple Store and then change it. (after market upgrades are easy, reliable and waaaaay cheaper than the original on the Apple Store).

Sounds good to me.

The critical part for Photoshop is the scratch disk, and with an SSD system drive you want to put it there. 512GB should be fine - but if you want to be future-proof 1TB is better. The Photoshop scratch files can be huge.

If that system drive is a PCIe M.2 (aka NVMe) drive - which it almost certainly is - then the amount of RAM isn't as critical as it used to be. These drives are so fast that the old scratch bottleneck is gone. 16 or 32GB RAM will do fine.

As for external storage and backup, the 8 or 10TB drives are coming down in price now, so that's a sensible investment. When I got mine they were terribly expensive, and starting to fill up by now