I'm pretty sure the Alienware PSU's were all ATX format prior to the Aurora R13. The R13, R14 & R15 are Dell proprietary PSU's. I believe the R16 PSU has gone back to a standard, but is SFF format.

I think even old system builders like me get tempted by something like an XPS or R16 when the price is right.

For those prices you are talking about, yeah, I'm using standard parts. 

I am watching that R16 and if it goes low enough....hehe.

:)

The motherboard on my R13 died after 14 months and that for me was the last straw.

I salvaged the 12900k CPU, the ram and 3090, and bought a midrange z690 board, a 240 mm NZXT AIO, PSU, and a new case.

The new build runs faster, runs cooler,  once I tweaked the far better BIOS options to get it to accept Dell's weird DDR 5 memory.

The new build is also both upgradable and repairable. Dell Alienware are now not easily repairable nor are they upgradeable. They BIOS lock the CPU to the generation supplied with your machine for a start, or as in the R13s case throttle the CPU because the supplied cooling solution is not of a sufficent standard to keep it cool enough. I won't spend another penny with Dell, there advertising promises plenty but the actual truth is hidden well away in the Spec Sheet, which funnily enough is not at the forefront of there advertising. You need to go look for it, because it won't find you.

@Iain K Mackay​   Alienware offerings prior to the Aurora R13 were much more upgradable with the ATX format PSU and much less proprietary nonsense in the motherboard. Of course you may not be able to upgrade to the next generation processor, so order the best possible CPU available at the time of purchase.

@ProfessorW00d​  No they were not, the R7 for a start featured a standard motherboard that Dell ensured could not be easily replaced with the way they attached the heat shield, and fitted it into the case.

Every Alienware PC Dell has produced since buying the brand name has been deliberately designed to ensure you can't upgrade anything and can't buy any spare parts. 

If I am wrong please point me to the Dell site that will sell me a replacement part for any component inside an Alienware PC.

@Iain K Mackay​    heat shield ???  Spare parts from Dell is not "upgrading". You do not need to get the upgrade parts from Dell because they are standard or customized to work. Just a few examples:

Aurora R11 external radiator

Aurora R12 custom loop

Area-51 R5   I upgraded the CPU to i9-9980XE, the graphics card to RTX 3080 FE, 64GB Crucial Ballistix RAM, Samsung 970 EVO Plus 2TB M.2 SSD, two 2TB Crucial MX500 2.5" SATA SSD's, bequiet! case fans, I purchased a Corsair AX 1600i PSU, but decided to leave the OEM 1500 watt PSU, added liquid cooling.

@ProfessorW00d​ I think he's talking about the CPU cooler mounting. Dell usually uses the Intel layout even on AMD, moves the copper block around as needed, and uses studs that are part of the case rather than the motherboard.

The result is issues if you try to mount an aftermarket cooler on an AMD system, or sometimes even on an Intel system pending the socket used.

@Vanadiel​   I don't think the Aurora R7 offered an AMD option, but regardless . . . you know from being in this Community over the years that there have been many, many successful 3rd party AIO CPU coolers installed on numerous Alienware iterations, both Intel and AMD processors. As I recall back in 2019 and leading into the pandemic it seemed there was at least one Corsair Hydro Series H60 (2018) thread started every day.

@ProfessorW00d​ That is true, but you are limited to what works as a backplate is not an option on some of these systems.