Yes get the x variant, its easy to limit, if you dont need the extra cores get the 7800x3d
Buildapc
i need my pc for photo editing, so i think 7900 or 7900x should be better than 3xd.
Anything that benefits from extra L3 cache will benefit from the x3D. I dunno if photo editing is one such tho, probably not.
You won't be changing the voltage on the CPU, but there's built in settings to limit the TDP down to whatever you want. If efficiency is also your goal you also want to limit the maximum clock speed (also in the same software).
do i need the mainboard with the "highest" chipset or the with the cheaper chipset it will be possible too?
In theory the A series chipset will run a 7950x3d or whatever the highest end CPU is. It's the power delivery of the board that matters more. Since you plan on underclocking it then in literally any board should work just fine with it.
I wouldn't cheap out that much on a board. Get a reasonable B series board, not some A series or bottom of the barrel B series if you're pairing it with such a high end CPU.
You cna use eco mode in UEFI BIOS to limit the power draw. It's easier and morenreliable than the software (ryzen master) method.
Why any of those instead of the 7800x3d?
why should i take this 78003xd? it takes more power and is slower tgan 7900x.
It's better for games, better performance. The cache makes a big difference. And has better cache/core distribution than the 7950x3d and 7900x3d, so it has consistently better performance for games.
The 7900 is only better for tasks that can take advantage of the extra cores, which are basically 0 for normal users.
spoken like a true gamer
Thank you all for your help.