I purchased the Intel I7 model and wanted to upgrade the PS as soon as I received it. So this is what I determined after the purchase. The heatsink on the processor is a <profane>. The power supply is not up-gradable with a standard PS inside the case and is around 240 watts max with a 8 pin molex for main power and 4 pin for PCIE to board power. Dell does not make their motherboards this machine has a Foxconn proprietary board which is useless to switch out to a better case as the front panel USB, audio and card reader ports are part of the motherboard off a L shaped extension. The board is low-line and only supports DDR3L with 16 GB max. 2 slots. Skylake processors will support DDR3L or DDR4 but the board has to have one type slot or the other. This is a DDR3L BOARD WITH A DUMMY DOWN UEFI BIOS. This means you cannot get greater than JDEC with 1T on memory as there are no memory setting and it will not even detect XMP or a higher JDEC like laptops do with faster memory. The power for SATA and the slimline optical come from a proprietary molex on the board and a custom made split-off wire connector. You can use and adapter to run two SSDs but the PS will only support one 3.5" an factory SATA slimline optical or 2 SSDs and the optical. The other drive cage on the right will support 2 2.5" SSDs or laptop drives with the blue Dell drive sleds thta they do not provide. There are two SATA power locations on the board but you can use only one at time unless you just connect the optical on the left and use a second harness on the right for the two 2.5" drives. There is only bearly 65 mm of height space for a heatsink change and the best you can come up with is the Noctua NH-L9x65 which as a 14MM tall 92 MM fan and you will have to modify (cut a small notch to gain full clearance on the drive cage that hold the optical. Unfortunately the Noctua fan has a proprietary IC in it: the NF-A9x14 uses Noctua's novel, custom designed NE-FD1 PWM IC that integrates Smooth Commutation Drive (SCD) technology. By providing smoother torque impulses, SCD suppresses PWM switching noises and thus makes the fan quieter at lower speeds. This IC is incompatible with this Dell/Foxconn board and the Fan spins up on boot but shuts down no spinning at desktop. Their PWM connection are screwed up and do not do a proper job with temp. I disconnected the PWM wire which makes the fan run at full speed not PWM and used the supplied Noctua fan speed reducer wire which has a resistor in it to reduce fan voltage to slow fan speed. The fan went from 5000 to 3500 rpm which is silent, 5000 is not. This after replacing the I7 6700 with and I5 6600K as I am going to use the I7 for another build and sell the 3650, I found the the processor temps were good at 37 degree to 30 with the fan at 3500 rpm. This machine has 2 SSD's with a modified dual SATA power adapter cable which I shortened to the minimum and moved punch-down connectors to line up with staked SSD's in the drive cage. My machine came with a Win 10 pro restore disk but it is Not the Anniversary edition 1607 but teh original November 2015 Win 10 release. It would have been better to download from Dell the restore files for USB as it might have been closer to 1607 or maybe even includes that. The M.@ slot holds a Qualcomm/Atheros single band 2.5 N card with bluetooth 4.0. It is not a dual band AC card and this is not an Upgrade option when buying from Dell. This means you would not be able to connect to a 5G router and and are limited to 54Mb max throughput theoretical speed. Wireless card can be changed to dual band. (not a dell card). If you have other question please post.