That same system sells for $799 directly from Dell. See more about it here:
http://www.dell.com/us/p/inspiron-3847-desktop/pd?oc=fdcwrt220h&model_id=inspiron-3847-desktop
So, you got good deal on it for $599 from Costco (especially since they extend the warranty by an extra year).
On the downside, it only has 2 DIMM Slots for memory, meaning it's "maxed out" at 16GB using 2x8GB.
But, 16GB is
more than enough memory for all but the most demanding users. Heck, I've only got 12GB of DDR3 in my current desktop (a Dell XPS 8500), and I have seen no issues that would require more for the way I use a computer.
The Power Supply in the Dell model you purchased would not support a really high end video card for more demanding gaming use (IOW, you may need to stick with more conservative settings with some games, versus the "Ultra" type settings) if you wanted to upgrade it's video card.
But, you can buy a pretty decent card now that would work in it's PCIe x16 slot if you needed something more powerful than the Integrated Intel graphics chipset
For example, this Super Clocked Nividia GTX 750Ti model is very popular, and will work in a system with a 300 Watt Power Supply:
http://www.amazon.com/EVGA-GeForce-750Ti-GDDR5-Graphics/dp/B00IDG3IDO/ref=zg_bs_284822_8
But, the integrated Intel graphics should be fine for most purposes, except for use with more demanding games. Also as time passes, you'll see faster and faster video cards that will work with lower power requirements.
Now, the latest "Smart Sharpen" filter in PHotoshop CC may be faster with a nicer video card (and the Nvidia GTX 750ti would be a good choice that you could plug into that system). But, most other PHotoshop features should work fine with the Intel Integrated Graphics (and BTW, a faster video card will not help anything with Lightroom, as it does not support GPU accelerated features).
Basically, it sounds like you found a pretty decent deal, with a computer using a very fast Core i7 4790 CPU, 16GB of memory, etc; at a really nice price point.
That's more than enough computer for most any need, even using higher end software for raw conversion, etc.; unless you're into gaming (in which case you'd probably want a system with a higher wattage power supply with a fast dedicated video card). But, I've upgraded similar Dell systems myself in the past (just buying a higher wattage power supply on sale from newegg, then adding a fast video card).
But, again, you could upgrade the video card to something dramatically faster than the Integrated Intel Graphics just by plugging in a card (like the GTX 750Ti series cards that will work with a 300 Watt PSU, without upgrading your Power Supply. IOW only "hard core" gamers wanting to use very high end video cards for the very fastest frame rates possible using the highest game settings may need to do something like a Power Supply upgrade.
So, I'd probably keep it if I were you, as you could always add a fast video card to it later (and even update it's power supply if you wanted a really high end gaming card), add an SSD to it if desired for the OS and Programs, etc. (but, I think you'll find that although an SSD is great for boot and program load times, it's really not going to help with processing speed using apps like Photoshop, so SSDs tend to be over rated).
I've got one myself (Samsung 830 Series SSD that I installed myself in my Dell XPS 8500 Desktop for the OS and Programs). But, frankly, since i don't reboot my system very often and programs I use more often are already going to be in the Operating System's disk cache in memory, for most practical purposes, it's not helping much.
Now... Costco does have some good deals on the XPS 8700, too. They have higher wattage power supplies, come with a dedicated graphics card, have more memory slots available (4 slots allowing up to 32GB total using 4x8GB); and more. For example, something like this $599 config using a Core i5 CPU:
http://www.costco.com/Dell-XPS-8700-Desktop-|-Intel-Core-i5-|-1GB-Graphics.product.100152990.html
It's more expandable and includes a dedicated video card (although not a high performance card). But, it's using a slower CPU (although you probably won't notice much difference with most apps) with 12GB (versus 16GB) of memory; but expandable to up to 32GB. So, it may be worth a closer look if you don't like the model you purchased for some reason
Or, move up to a model using the same Core i7 4790 CPU your new system came with. Costco has multiple XPS 8700 systems available equipped with the Core i7 4790.
Or, or at what Dell currently offers directly (but, you would have an advantage of an extra year warranty with Costco, that you'd have to pay for if buying a system directly from Dell).
There are pros and cons to any of them. But, on the surface, the box you purchased should handle most anything you'd need (including editing with Photoshop), as that Core i7 4790 CPU is a very nice processor, and 16GB of DDR3 should be more than enough for most any purpose.
Personally, I'd probably buy a refurbished XPS 8700 with a Core i7 4790 in it, adding more memory, etc. myself. I've bought 7 refurbished Dell computers over the last 10+ years for me and wife to use (including my current XPS 8500 desktop, an Inspiron 15 laptop I use, a Dell 11Z netbook our niece is using now, and others). I just look for bargains on the Dell refurbished computers, and add more memory, etc. myself later.
Again, there are pros and cons to any of them.
--
JimC
------
